Status: Completed
Description: <p>We propose to further advance the technology maturity of the miniature atomic drag-free accelerometer that was first developed under the Planetary Instrument Definition and Development Program (PIDDP). The accelerometer uses free-fall atomic particles as proof masses and quantum wave interference for inertial force measurements. This novel type of accelerometer will provide unprecedented performance in both sensitivity and stability on-board an orbiter without the need for calibration. The accelerometer measures all of the non-gravitational forces of the spacecraft and thus enables the reduction and elimination of the errors induced into the planetary gravity measurements through radiometric orbit determination. Radiometric gravity measurements have provided unique and valuable information about the interior structure and dynamics of planetary bodies. The confirmation and determination of the fluid core size of Mars are great examples of the science achievable from gravity measurements. For other planetary bodies, where non-gravitational forces are severe and dynamic, an on-board accelerometer will provide the drag-force measurements necessary for obtaining high precision gravity data. The need and benefit of such accelerometers are exemplified by the inclusion of the Italian Spring Accelerometer on Mercury Planetary Orbiter in the BepiColombo mission. The atomic accelerometer instrument technology is based on the quantum atom-wave interferometers. It utilizes quantum interference of neutral atoms, laser cooled to microKelvin temperatures without bulky cryogenics. One major difference of the atomic accelerometer from traditional mechanical accelerometers is the use of totally free-fall proof masses without any spring or measurement back action. This allows for drag-free measurements, and therefore, high acceleration sensitivity and stability without the need of on-board calibrations. Through the PIDDP program we have demonstrated the concept of a miniature drag-free reference instrument, developed from a previous full rack-sized instrument to a simple and shoebox-sized sensor system. The objective of the MatISSE effort is to develop an integrated instrument system to TRL5, perform full characterization and evaluation on the ground, and make it ready for microgravity performance demonstration and validation. With the successful development and validation of the atomic accelerometer technology, future missions to orbit Titan, Enceladus, and Venus will be able to carry the precision U.S. accelerometer. This will enhance gravity measurements by enabling the orbiter to fly low in altitude, for higher gravity signals, without the concern of atmosphere drag-induced errors. With better measurements of gravity higher harmonics and tidal variations, scientists will be able to learn more about the density distribution in depth, shape, and the interior structure of a planet body in hydrostatic equilibrium. For planets with heavy atmospheres such as Venus, one may be able to determine the seasonal atmospheric loading through time-varying gravity measurements.</p>
Status: Active
Description: <p>Goals and Objectives: This MatISSE effort will continue the maturation of the Luminescence Imager for Exploration (LIfE), an automated bright-field and epifluorescence microscope developed under the NASA Concepts for Ocean worlds Life Detection Technology (Luminescence Imager for Exploration; 2017-2018) and the Instrument Concepts for Europa Exploration-2 (Europa Luminescence Microscope; 2019-2022) programs. LIfE will be developed under MatISSE to TRL 5 (formally) as end-to-end system "that can be proposed in response to future announcements of flight opportunity without additional extensive technology development (approximately TRL 6)". In other words, TRL advancement to the point where the instrument can be matured fully to TRL 6 relatively quickly (~18 months), for example during Phase A of a planetary mission. Methods/Techniques: For autonomous sample analysis, LIfE isolates insoluble particles on micron and sub-micron pore-size filters and analyzes them using fluorescence imaging with sub-micron spatial resolutions, enabling the detection and quantification of organic and inorganic structures. LIfE uses three operational modes: 1) Bright-field imaging for visual structural measurements. 2) Fluorescence imaging of stained key compositional cellular features (e.g., membrane lipids, proteins, and nucleic acids). 3) Autofluorescence imaging with DUV and visible excitation sources. Perceived Significance: LIfE directly addresses the goals of the MatISSE program and NASA goals by providing enabling technology for flyby, orbital, and landed missions that is suitable for multiple payloads and payload implementations. NASA Science Mission Directorate's "Science 2020-2024: A Vision for Scientific Excellence," establishes priorities for exploration and scientific discovery that includes the "Search for Life." LIfE is specifically designed to address this goal by providing an instrument with the capability to identify and characterize structural, compositional, and functional indicators of life. The impact of a discovery of non-terrestrial life would be profound, affecting our understanding of the science of life and its distribution in the universe, as well as shaping exploration priorities for the coming decades.</p>
Status: Active
Description: <p>Future missions to Mars, Europa, Enceladus, and beyond may seek the molecular signs of extraterrestrial life through chemical analysis of acquired samples. Particularly on ocean worlds such as Europa and Enceladus, samples may contain trace ocean-borne molecular biosignatures of extant life that may or may not share similarities to those of terrestrial life. In situ analyses must be prepared to detect and characterize a wide range of possible molecular species, structures, and patterns, typically with exquisite sensitivity and within a complex, poorly-characterized planetary environment. The Extraterrestrial Molecular Indicators of Life Investigation (EMILI) is designed to meet or exceed the requirements of such missions for organic molecular analysis through a powerful combination of dual chemical separation and both optical and mass spectrometry detection techniques, realized in an integrated, compact instrument package fully compatible with anticipated flight resources and conditions. The full EMILI instrument combines two sample analysis subsystems to provide wide-ranging and complementary detection of organic compounds and inorganic salts. The Gas Analysis Processing System (GAPS) uses a chemical derivatization protocol with gas chromatography (GC) separation prior to detection in an ion trap mass spectrometer (ITMS) to enable full characterization of lower-polarity, volatile and semi-volatile molecules such as fatty acids and hydrocarbons. The Organic Capillary Electrophoresis ANalysis System (OCEANS) uses a liquid-based extraction protocol with CE separation to enable precise analysis of more water-soluble/polar compounds. OCEANS features a laser-induced fluorescence detection mode to perform ultra-sensitive quantitative analysis of chiral amino acids. In EMILI, OCEANS is additionally coupled to the same ITMS through a novel electrospray ionization interface. The common ITMS allows EMILI to identify and cross-correlate molecular species and patterns, detected through either or both protocols, of molecular weights to over 1000 u, potentially revealing complex biosignatures such as alien oligopeptides and informational polymers. With previous support under the Instrument Concepts for Europa Exploration – 2 (ICEE-2) Program, EMILI instrument design has been validated through end-to-end breadboard testing in all modes using flight-like protocols. For a Europa Lander and similar mission configurations, EMILI has reached technology readiness level (TRL) 4 for the full system, TRL 5 for selected subsystems, and TRL 6 for several individual sensor assemblies, notably the high-heritage GC and ITMS analyzer. Here we propose to advance the TRL of EMILI across the board, with a special focus on the OCEANS-ITMS subsystem and its critical CE-ESI-ITMS interface that will reach TRL 6 through stepwise development and full flight environmental verification of an EMILI Engineering Test Unit (ETU). The ETU will feature a highly-compact flight-like housing and electrical/fluidic connections and interfaces, and will be subjected to performance testing under thermal, vacuum, vibration/shock, electromagnetic compatibility, and power/energy requirements relevant to Europa Lander, Enceladus Orbilander, and Mars surface missions. A comprehensive review of TRL 6 status, including any mission-specific conditions such as radiation tolerance for Europa based on completed ICEE-2 work, will be conducted in the final year, leaving time and resources available for retuning and publication of a complete analysis of readiness and path-to-flight requirements for specific missions that may benefit from EMILI-enabled science.</p>
Status: Completed
Description: <p>I. SCIENCE GOALS AND OBJECTIVES The proposed instrument is the next-generation Cold OBject RAdiometer (COBRA) designed for ice giant, icy satellite, and lunar science. Specifically, COBRA will perform measurements of (i) the atmospheric structure of the ice giants through nadir sounding in the far-IR, (ii) the radiative balance of planetary bodies and their satellites, including ice giants, and (iii) the thermophysical properties of satellites and primitive bodies in order to derive information on their surface structure and composition. The instrument we are proposing is an enhancement of JPL’s Mars Climate Sounder (MCS) on MRO and Diviner Lunar Reconnaissance Explorer (Diviner) on LRO which have provided breakthrough science by measuring the thermal infrared properties of the atmospheric limb of Mars and the surface of the Moon, respectively. COBRA is a highly accurate radiometer that measures radiance in a set of bandpass filters spanning 0.3-200 µm and can help answer important questions such as the following: • What is the atmospheric circulation in the upper troposphere of Uranus and Neptune, and how does this circulation interact with other parts of the atmosphere? • Is the internal heat flux from Uranus as low or that from Neptune as high as currently assumed? • What is the small-scale variability of thermal properties, composition, and polar cold-trap distribution of the Moon?</p> <p> </p> <p>II. METHODOLOGY We are proposing to develop the next-generation (beyond MCS and Diviner) multi-spectral IR/Far-IR remote-sensing imaging radiometer specifically to measure cold bodies with temperatures that reach below 60 K (Neptune, Uranus, their satellites, and the Moon’s poles). The enabling technology for MCS and Diviner is the uncooled thermopile arrays developed at JPL. COBRA extends the capabilities of these thermopile arrays so the pixel pitch (100 um), format size (128 x 64), and spectral response (e.g. optical coating) are designed to make accurate and sensitive radiometric measurements of extremely cold objects. We will build the instrument using a new optical design that has an intermediate focus which allows for the integration of a filter block that is compatible with the new larger arrays. Finally, we will use a compact pointing mirror to replace the bulky actuators flying on MCS and Diviner. This instrument will have nearly 100x more pixels than the state-of-the-art and a sensitivity per pixel that is nearly two times higher. This performance will be achieved with an instrument that is 50% less massive than MCS or Diviner.</p> <p>III. RELEVANCY The proposed research is directly relevant to NASA’s MatISSE program since this program is to “develop and demonstrate planetary and astrobiology science instruments to the point where they may be proposed in response to future announcements of flight opportunity without additional extensive technology development”. This proposal will develop new technologies that significantly improve instrument measurement capabilities for planetary missions and retire major technological risks prior to science instrument solicitation. The multi-spectral IR/Far-IR remote-sensing imaging radiometer we are proposing to build will be far more capable than MCS and Diviner in terms of spatial/spectral resolution and sensitivity, BUT will be significantly lighter and more compact. The thermal infrared radiometer technology proposed here is applicable to a wide range of Discovery, New Frontiers, and flagship missions identified in the Decadal Survey including Comet Surface Sample Return, Io Observer, Uranus or Neptune orbiter. Because this proposal is relevant to MatISSE, it is intrinsically relevant to NASA PSD and SMD.</p>
Status: Active
Description: <p>Relevance: Seismic studies provide definitive knowledge of internal planetary structure. Despite several missions to small bodies, current knowledge of their interiors is still inferred and unknown in detail. Direct knowledge of the internal structure via seismology can address this knowledge gap and constrain theories about asteroid formation and evolution—a priority goal in the Planetary Science and Astrobiology decadal strategy for 2023-2032 [Origins, Worlds, and Life 2022]. Knowledge of asteroid interiors is vital for establishing mitigation techniques for hazardous near-Earth objects and exploring in-situ natural resources. Methodology: To investigate asteroid interiors, we propose to raise the TRL of a Silicon Audio broadband seismic instrument—with a similar noise floor and sensitivity to the Insight VBB—from 4 to 6. The original instrument is a novel combination of a classic seismometer and a laser interferometer. Micron-scale movements of an internal mass are recorded as induced current, while the laser system records submicron-scale motions. This allows for a small (<400 g), sensitive (1x10-8 m/s2/Hz1/2) broadband (0.01-100Hz) seismic instrument that is competitive with state-of-the-art planetary seismometers. The 3-axis instrument is insensitive to tilt over 180º. Here we pursue a redesign of this system, improving its sensitivity and enabling it to capture predicted seismic signals on asteroids. We will accomplish this by enlarging the sensor proof-mass and updating the internal spring system We will also pursue subsurface deployment using a ballistic penetration technique in partnership with Honeybee Robotics. Subsurface deployment is accomplished by a penetrator whose shape and mass are optimized to puncture through surface regolith below the diurnal skin depth. This approach is similar to the proposed Lunar-A mission concept led by the Japanese Space Agency (JAXA) and NASA’s launched Deep Space 2 probe. Burial will enable lower noise and power by automatically creating an isothermal environment while improving seismic coupling. The proposed effort will demonstrate seismic sensor implantation to several centimeters depth via simulation and a microgravity environment test. We will advance the deployment mechanism from TRL 4 to TRL 6. Objectives: 1) Raise the TRL of the low-noise broadband Silicon Audio optical three-axis seismometer from 4 to 6. 2) Demonstrate burial with the Honeybee system raising the TRL from 4 to 6.</p>
Status: Completed
Description: <p>SCIENCE GOALS AND OBJECTIVES We propose to build a low-SWaP engineering model of the Venus Wideband Submillimeter Heterodyne Spectrometer (V-WiSHeS), a high spectral resolution instrument optimized to remotely measure trace gases and continuum opacities in Venus’ middle atmosphere. V-WiSHeS will enable spatial and temporal profile measurements of wind, temperature, composition, and aerosol opacity, in both nadir and limb-sounding modes, to reveal the critical role of Venus’ middle atmosphere at altitudes spanning 60 to 150 km. With unprecedented wideband spectral coverage for submillimeter heterodyne planetary flight spectrometers, V-WiSHeS will cover 64 GHz of bandwidth between 529 and 600 GHz, with a spectral resolution as fine as 500 kHz (resolution 0.0000167 cm-1, R=1,000,000 at 557 GHz). These capabilities enable measurements of aerosol continuum opacity, thermal profiles, and isotopic abundances of the gases H2O, H217O, H218O, HDO, CO17O, CO18O, 13CO18O, 13CO17O, CO, 13CO, C18O, O3, OO17O, OO18O, O18O, H2S, H234S, H233S, H2SO4, ClO, 37ClO, H2O2, SO, SO2, 34SO2, OCS, O13CS, OC34S, OC33S, NO, and NO2.</p> <p> </p> <p>The V-WiSHeS instrument is significantly leveraging our team’s previous MatISSE and DALI efforts. In our former MatISSE project, we matured subcomponents of a passive remote sensing planetary flight spectrometer called SELFI, the Submillimeter Enceladus Life Fundamentals Instrument. In our DALI effort, we incorporated – for the first time – broadband ASIC digital spectrometers into the design of the heterodyne spectrometer SSOLVE, the Submillimeter Solar Observation Lunar Volatiles Experiment. In this present effort, however, we will build on our SELFI and SSOLVE technologies, most notably by expanding the spectral coverage, while simultaneously reducing both mass and power.</p> <p>METHODOLOGY We are developing a novel submillimeter planetary flight spectrometer that achieves both high spectral resolution and a groundbreaking 64 GHz of broadband spectral coverage in a low-power, low-mass, and compact instrument. Such an advancement is enabled in part by incorporating four Application-Specific Integrated Circuit (ASIC) spectrometers into the V-WiSHeS back-end, which are critically needed for their high-speed computational capacity. Moreover, we are able to simultaneously achieve wide spectral coverage by implementing an innovative time-multiplexed frequency switching scheme that utilizes four 4-GHz ASIC spectrometers to achieve a 16 GHz instantaneous bandwidth, in which we frequency switch four times to reconstruct 64-GHz of coverage (529 -- 561 GHz; 568 -- 600 GHz). At the end of this 3-year MatISSE project, our highly experienced team will deliver a TRL 6 instrument prototype to NASA, ready for a planetary flight mission opportunity.</p> <p>RELEVANCE This proposed work is responsive to the stated objectives of the MatISSE program by advancing the development of V-WiSHeS, a planetary space flight remote sensing instrument with unprecedented spectral coverage for submillimeter heterodyne flight spectrometers. We will demonstrate that V-WiSHeS is an appealing instrument for a future Venus orbiter with its broad spectral coverage and high spectral resolution. V-WiSHeS provides numerous compelling science capabilities, which will help to unravel fundamental science questions at Venus (e.g., What do diverse climates such as Venus’ reveal about the vulnerability of Earth’s environment? What roles do the targeted trace gases play in Venus’ physical and chemical atmospheric environment?). V-WiSHeS will be an essential part of any orbiter mission to Venus including New Frontiers, Discovery, SIMPLeX, and SmallSat concepts. Beyond that of Venus, V-WiSHeS is applicable to numerous planetary targets such as Mars, Ceres, Jupiter, Io, Europa, Saturn, Titan, Enceladus, Uranus, Neptune, Triton, KBOs, and comets.</p>
Status: Completed
Description: <p>Understanding the origin, distribution and processing of organic compounds in cryogenic planetary environments is one of the most compelling future directions in Solar System research. Such organics are structurally and functionally diverse, despite their low-temperature origins, and are thus thought to constitute an enabling prebiotic inventory for the potential emergence of life. Top-priority planetary science goals for the coming decades will require detailed in situ studies of surface and near-surface composition to elucidate molecular structure and unambiguous identification of complex mixtures of organics from icy environments. These planned investigations will further our understanding of primordial sources of organic matter, and the role and distribution of ancient Solar System and interstellar materials, with implications for the delivery of water, volatiles and hydrocarbons to Earth and other planetary objects. Saturn’s moon, Enceladus, has a rich organic chemistry requiring a modern high-resolution mass spectrometer to fully characterize its molecular evolution which could range from abiotic synthesis to extant cellular biology. We propose to develop a highly capable mass spectrometer instrument that will transform our understanding of Enceladus and other planetary environments such as the dwarf planet Ceres and comets like 67P/Churyumov-Gerasimenko. This comprehensive, in situ investigation requires versatile and high-performance instrumentation capable of: 1. Quantitative measurements of trace levels (e.g., ≤ ppmw) of organic and inorganic compounds over a wide range of volatility, ionization potential and molecular weight; 2. Selective excitation and isolation of targeted mass ranges for enhanced signal-to-noise (and by extension limits-of-detection) and controlled ion manipulation and ejection; 3. Induced fragmentation of parent molecules and structural analysis of daughter ions via tandem mass spectrometry (i.e., MS/MS operations) for the differentiation of isomers; 4. Mass discrimination and disambiguation of isotopologues and isobaric interferences with high-resolution of 50,000-100,000 (FWHM at m/z=100 Th) and mass accuracy of 5-20 ppm for ions with mass between 50 and 2000 u; and 5. Measurements of enantiomeric excess using a gas chromatograph and derivatization. The proposed Advanced Resolution Organic Molecule Analyzer (AROMA) instrument will meet all of these performance requirements by integrating a technically mature, highly capable linear ion trap (LIT) with a high-resolution OrbitrapTM mass analyzer in an efficient and compact system. The AROMA instrument design leverages efforts at NASA GSFC to design and improve upon the linear ion trap for the Mars Organic Molecule Analyzer (MOMA) mass spectrometer for the ExoMars 2022 rover and experience gained in the development of an orbitrap instrument prototype for the Characterization of Ocean Residues and Life Signatures (CORALS) instrument for a Europa lander. The high heritage LIT front end of AROMA will be interfaced to a streamlined set of ion optics that will serve to collimate, compress and accelerate (“crunch and punch”) ions ejected towards an advanced (TRL5) Orbitrap mass analyzer that has been adapted for spaceflight by the CosmOrbitrap Consortium (Co-Is from France). Together, these components define an innovative and potentially game-changing instrument capable of high-sensitivity and high-resolution mass spectrometry in addition to organic structural analysis. The maturation of the AROMA instrument will build on the PICASSO funded AROMA project to incorporate a matured laser and laser injection optics, an extended mass range, and ensure compatibility with ocean worlds and primitive bodies. Environmental testing will be performed to ensure the instrument can withstand general environmental level vibration and shock, thermal cycling, and dry heat microbial reduction consistent with planetary targets.</p>
Status: Completed
Description: <p>The surface-atmosphere exchanges of momentum, heat, and tracers (e.g., water, CH4, dust) on Mars are critical forcings that control weather, climate, aeolian processes, water stability, etc. These exchanges occur through turbulent eddies, requiring fast sampling, and high sensitivity and precision to resolve, a capability out of reach of all previous martian wind sensors. Our Mars Sonic Anemometer is ~20X faster, more sensitive and precise than predecessors and enables direct measurement of the turbulent eddies, and thus their surface-atmosphere exchanges. Measurements with our Mars Sonic Anemometer would advance our understanding of aeolian processes, saltation, dust lifting, the energy balance of the diurnal convective layer, the stability of water in the subsurface, etc. These advancements are all relevant to Decadal Survey & NASA Strategic Goals such as “Understand the processes and history of climate.” Our instrument would also likely contribute to atmospheric model improvement through providing a richer constraining data set, likely reducing future risks in EDL to, and Ascent from, Mars.</p> <p> </p> <p>It would be applicable on essentially all but the absolute smallest of Mars landers, requiring only ~500g and 500mW. With minor adaptations, it could also be used on a Venus cloud-level balloon mission, in Earth’s stratosphere (potentially commercially), on Titan, or on Saturn or Ice Giant Probes.</p> <p>With support from PICASSO, the Mars Sonic Anemometer is currently at TRL5, having demonstrated prototypes that meet our science requirements under Mars conditions in the Danish Mars Wind Tunnel. We will harden our ultrasonic transducers against shock and vibe, and thermal extremes and cycling. We will also optimize the design of the sensor head (“spider”) to minimize wind shadowing, optimize the electronics to reduce mass and power while using rad-hard parts, and migrate the software to flight requirements. Finally, we will validate the instrument to TRL6 with performance tests in a representative martian environment, thermal extreme and thermal cycling tests, and shock and vibe tests. These will place the Mars Sonic Anemometer in position to be included on any upcoming Mars surface mission, or with small adaptations, mission opportunities at Venus, Earth, Saturn, Uranus or Neptune as discussed above.</p>
Status: Active
Description: <p>We propose to build, test, and validate High Sensitivity Silicon Carbide (SiC) Focal Plane Detectors for miniaturized instruments that can enable near-ultraviolet remote sensing of lunar surface and other planetary bodies. Silicon Carbide is a highly promising material, which has demonstrated at least two orders of magnitude better sensitivity in the Near Ultra-Violet (NUV) over previously used materials. To our knowledge, this project would be the first to harness 4H-SiC large format, small pixel, solar blind, linear detector arrays, with their unique material properties for the purposes, of integration into remote sensing planetary spectrometer instrumentation. We would leverage the manufacturing and integration experience of our team in order to fabricate the detectors and then package and integrate them into a focal plane assembly. We will then test the focal plane array in a spectrometer set up we have in hand. Our team is uniquely equipped for this project given previous work that has been done with 4H-SiC material and would leverage previous developments that used SBIR, GOES-R and NASA/GSFC internal research and development funding. The work proposed by the project would raise the technology readiness level of these detectors from 2 to 4, with a future MATISSE proposal aimed at additional maturation of the detectors as a viable path for planetary instrumentation impacting science identified in the decadal survey. The proposed 4H-SiC focal plane detectors would be able to obtain remote sensing radiance observations with a higher detectivity than previous generations of 200-340 nm NUV spectrometers with a resolving power of R~200. The compact power, size and cost footprint of these detectors would enable important NUV observations of several different planetary targets, including the Moon, Icy Worlds, Io, small bodies such as comets and asteroids, and atmospheres of certain planets. The miniaturization of such detectors with readout electronics is also key to enabling NUV instrumentation in SmallSats or added to larger, conventional spacecraft as CubeSat ride share missions.</p>
Status: Active
Description: <p>The goal of this work is to mature to TRL 6 an instrument that can rapidly scan, find, and identify organic materials, facilitating the search for evidence of life on Mars or ocean worlds. Given the potential presence of organic materials on these bodies, NASA’s goal of searching for life is now one of identifying concentrations of organic biosignatures. Therefore, we seek to mature a revolutionary instrument that will uniquely image organic materials at 10s of ppb levels from stand-off distances (to 5 m) and can be fielded by small landers, rovers, or unmanned aerial vehicles (UAVs). Objective 1 is to advance and miniaturize the mechanical design, including swapping the current rectangular detector for a square detector, to produce an ultra-lightweight and space-ready version of the collection optics and spectrometer components. Objective 2 is to further miniaturize and adapt electronics and software from previous flight instrumentation. Objective 3 is to demonstrate and test the optical and detector components together in a Mars-like thermal vacuum chamber, and to shock and vibrate these components to demonstrate their feasibility to operate in a space environment. We propose to use time-resolved fluorescence imaging to uniquely highlight organic materials, maturing breadboard components that have been validated in the laboratory (TRL 4). The “OrganiCam” instrument is a laser-induced time-resolved fluorescence imager and Raman spectrometer that leverages Mars 2020 SuperCam technology. OrganiCam’s 80 mm focal length optics are designed to image 1 mm fluorescent organic features, and collect their spectra, at 2 m, with 10s ppb level detection limits, while the Raman spectrum provides organic identification and mineralogic context. OrganiCam uses a diffuse expanded pulsed laser to illuminate a 20 degree region and uses camera optics and an intensified CCD detector to collect the prompt (100 ns timescale) fluorescence from organic material, thus collecting a fluorescence image of the illuminated area. Simultaneously, OrganiCam collects a fluorescence spectrum on the same detector. The laser diffuser is then switched to a collimated laser beam to collect a Raman spectrum of a spot. The detection of organics and biological materials in the OrganiCam imager relies on the behavior of fluorescence lifetimes of these materials; organics and biopolymers have very short lifetimes and minerals have long-lived luminescence. Hence, OrganiCam uniquely differentiates between organics and minerals by only recording signals of the fastest fluorescence emissions using a fast-gated (100 ns) intensified detector. Simultaneous collection of the image and spectrum of a target from up to 5 m away allows OrganiCam to have a very compact and lightweight design. These savings allow OrganiCam to fit onto a UAV (~4 kg payload), which could be a follow-on to the 2020 Mars Helicopter demonstration mission, to quickly survey an area for biological or organic materials and to use Raman to identify molecules and provide mineralogic context. OrganiCam is suited to address major questions outlined in the NASA 2015 Astrobiology Strategy of identifying, exploring, and characterizing environments for habitability and biosignatures. OrganiCam can help answer questions of “What contextual information is required to [interpret] biosignatures?” and “What new types of biosignatures can we identify and how can they be detected?” OrganiCam will address important questions from Vision and Voyages for Planetary Science in the Decade 2013-2022, including “assess[ing] whether life is or was present on Mars in its geochemical context.” OrganiCam will “characterize complex organics, the spatial distribution of chemical […] signatures, and the morphology of mineralogic signatures.” OrganiCam is equally suitable for ocean world lander missions. OrganiCam is planetary science oriented and its maturation from TRL 4 to TRL 6 fits squarely in the MATISSE program.</p>
Status: Completed
Description: <p>Aeolian processes are the primary agent of change on Mars today and, through dust lifting, control Mars climate. They also play a significant role in shaping Titan’s surface. On both planets, sand-sized grains will "saltate" along the ground in wind-driven, bouncing trajectories, forming ripples and dunes where grains accumulate. Expanses of ripples and dunes have posed significant hazards to both MER vehicles and the MSL and Mars2020 rovers, affecting traverses and the efficiency of surface operations. The energy of saltating grains has eroded outcrops pervasively at both MER sites and the MSL and Mars2020 sites. Saltating grain trajectories are energetic enough also for sand to have accumulated on rover decks as well as against the fore-optics of the MSL Mastcam, ~2 m above the surface, and damaged the wind sensors on both MSL and Mars2020, thus indicating the potential hazard that saltating grains represent to future landed hardware, including infrastructure supporting potential human surface operations. The minimum wind speed required to initiate sand saltation on Mars, Titan, and Venus is unknown, currently predicted only from laboratory experiments. Likewise, saltation trajectories are poorly understood; their energy as a function of height and wind speed has only been modeled numerically and remains untested in situ. Because the grain properties as well as their kinematic behavior are fundamentally important to understanding how saltation operates on these bodies, we are developing a sensor capable of yielding a rich data set about saltating grains on (e.g.,) Mars or Titan. Existing terrestrial saltation instrumentation is inadequate for planetary application not only because of the demands for simplicity, ruggedization, and autonomy, but also because the extent of our understanding of saltating grains and associated aeolian processes is significantly less mature on other planets. For example, the leading terrestrial instrument (the “SENSIT”) only counts particles and reports their energy of impact. This does not allow particle mass to be deconvolved from particle speed. The proposed project follows directly on from a previous PICASSO grant to develop our saltation sensor from concept to TRL4. Our instrument returns not only the count of impacts, but also each impacting particle’s energy and momentum, and impact height. This level of information content is required to advance our understanding of the saltation process in exotic planetary environments. The existing PICASSO saltation sensor prototype is tightly coupled with a sister instrument, a sonic anemometer (also developed by this same team under PICASSO and MATISSE funding). We will mature the saltation sensor to TRL6 in this effort, leveraging highly on the electronics developed for the sonic anemometer, so that these two instruments can share back-end electronics (i.e., the instrument computer), and have significant commonality in the instrument front-end electronics and sensor transducers.</p>
Status: Active
Description: <p>Our diverse team of engineers and atmospheric physicists proposes to develop a 2-µm high-power, high-repetition rate fiber laser transmitter. This laser is the key component of the novel pulsed Differential Absorption Lidar (DIAL) for Martian atmospheric CO2 and pressure profiling. Martian atmosphere consists dominantly of CO2 (about 95%). Global CO2 observations, especially over polar regions where dry ice deposition frequently occurs, are urgently needed considering current pace of Mars’s exploration. Furthermore, air pressure and pressure gradient are the most important variables for atmospheric dynamics that drive atmospheric motion and transports of mass, heat and momentum. Although air pressure is extremely important in characterizing Martian atmosphere, significant global observation gaps exist. There is no systematic observation of horizontal and vertical pressure distributions. Martian atmospheric CO2 and pressure observations will fill this observational gap and address multiple planetary science priorities and objectives, especially those identified by the NASA Science Plan 2020 – 2024 and Planetary Science Decadal Survey. Improving our understating of Mars’s atmosphere and its dynamics is crucial for future Mars exploration. This project will take the advantage of the expertise from all team members, the success of the Earth’s CO2 DIAL system development, and the invaluable progresses in fiber laser amplifier from multiple NASA SBIR projects. The laser of the transmitter will be developed from a single-mode distributed feedback (DFB) seed laser plus optical fiber amplifier system. Wavelength stabilization and variation monitoring will be applied to seed laser. For the high-power fiber-laser amplifier, technologies for both pulsed systems at nearby wavelengths and continuous-wave lasers at the needed ones will be used to achieve our requirements of 2-5 mJ laser pulse energy at a pulse repetition frequency of 1-2 kHz. A pulsed laser output of millijoules at 2.05 mm has not been accomplished before. With this laser, a transmitter toward future Martian CO2 DIAL system will be constructed. Our research team consists of laser/lidar engineering, remote sensing, atmospheric science, and planetary science expertise. Our team has successfully collaborated for many years in many lidar technology development efforts, Earth’s CO2 lidar development, atmospheric observational project collaborations, space/suborbital mission formulation, implementation, and execution processes. For this project, NASA Langley Research Center (LaRC) will be responsible for project management, overall system design and fabrication, instrument integration, and testing. AdValue Photonics, Inc will be in charge of the 2.05 µm amplifier manufacture and provide financially in-kind manpower support. This is a 3-year project, starting on October 1, 2022. The entry TRL of the transmitter is 2 and at the end of this project the TRL will be at level 4. Furthermore, this proposed work will advance the entire Martian CO2 DIAL system to TRL-3.</p>
Status: Active
Description: The Global Reference Atmospheric Model (GRAM) Suite is an engineering-oriented atmospheric model that provides estimates of mean values and statistical variations of atmospheric properties for various planetary bodies. GRAM is used for modeling and simulations to provide atmospheric properties that are then used for trajectory and vehicle performance predictions. GRAM has been one of most widely used engineering models of the atmosphere since development started in the 1990’s with updates and new atmospheric models being released in timely increments since then. Since FY2018, SMD has been providing funding support to continue enhancements of GRAM to support operations for several planetary missions and create atmospheric models of planetary models not available. In 2023, the new GRAM Suite was an Honorable Mention for NASA Software of the Year.
Status: Active
Description: <p>NASA utilizes refrigeration for a range of stowage, biological/medical, and personnel thermal management applications. However, the use of refrigerants can impose risks associated with both personnel safety and mission success/duration that requires careful refrigerant leak monitoring, replacement, and pressure/temperature control. Exacerbating these concerns, recent legislation mandates the phase-down of production, procurement, and usage of high global warming potential (GWP) hydrofluorocarbons (HFCs) such as R134a/R236fa used in existing vapor compression systems. Alternative refrigerants such as HFO-1234yf, ammonia, and carbon dioxide are being considered, but often-times trade a GWP-advantage for disadvantages related to flammability, toxicity, thermodynamic and transport properties (lower-COP), stability, and/or equipment costs. Thus, there is a desire to move away from standard high-GWP vapor compression refrigeration approaches and adopt alternatives to improve platform efficiency/endurance and accommodate recent GWP regulatory drivers. The University of Illinois Urbana-Champaign, in collaboration with Barrow Green LLC., will develop novel gradient-structured (GS) NiTi materials and low-force bending-mode elastocaloric regeneration cooling architectures to advance the performance of refrigeration systems for NASA exploration applications. We will explore laser-induced gradient structuring of nanograined NiTi materials to spatially tune grain size in monolithic NiTi samples. This facile localized grain refinement approach will yield a high-throughput methodology to produce bulk NiTi materials with latent heats exceeding 8 J/g, thermal conductivities from 12 to 22 W/mK, and low stress hysteresis (~60 MPa). Critically, the combination of these salient properties will result in materials with coefficients of performance (COP) exceeding most standard elastocaloric materials (target 10-25). The developed materials are critical to enabling a novel low-force bending-mode regenerative elastocaloric cooling architecture. The rotary-based elastocaloric cooling design has the benefits of discrete hot and cold zones, continuous (as opposed to oscillating) cooling, inexpensive rotary actuation, and scalability, which represents a significant advancement for compact, long lifetime, and inexpensive elastocaloric cooling.</p>
Status: Active
Description: <p>Space exploration applications require high volumetric and gravimetric power density cooling systems for personal climate control, thermal management of sensitive components, and cooling of sensors. Elastocaloric refrigeration has been limited by 1) lack of high performance elastocaloric effect (ECE) materials developed specifically with appropriate materials-level performance metrics in mind, and 2) limited application of co-design principles to couple ECE materials and refrigeration systems development. We propose to develop a prototype high efficiency ECE refrigerator, specifically designed to increase system-level gravimetric and volumetric cooling power density over state-of-the-art (SOTA) by 2× to 10×. This research project will consist of: (i) developing an irreversible thermodynamic model capable of quantifying materials response to active regenerative thermal and load cycles, (ii) data-enabled materials design of high performance ECE materials based on relevant figures of merit, and (iii) co-design of a multi-zone active regenerative ECE refrigerator to evaluate the interaction between materials properties and system-level performance. We will develop a prototype demonstrator system, to evaluate (i) scaling relationships with total cooling power, and (ii) use of a refrigerator architecture to achieve a larger working DT (up to a design target of 30 K) across a multi-zone active regenerator, and higher cycle frequencies (to 1 Hz).</p>
Status: Active
Description: <p>As government and commercial entities expand their activities in the orbital space surrounding Earth, the simultaneous increase in orbital debris causes new challenges related to space safety and sustainability. The orbital debris population contains a significant number of small, hard-to-track fragments that are scattered across larger regions of space and pose a potentially lethal threat to spacecraft components. We propose to devise new passive dust cloud systems as a cost-effective solution for the active removal of small orbital debris.</p>
Status: Completed
Description: The availability of efficient heat switches, which facilitate the dissipation of heat to the environment at high temperatures (> 15°C) and prevent heat exchange at low temperatures (< -15°C), would allow to maintain all vehicle components within an appropriate temperature range throughout all mission phases and enable an unprecedented exploration of the moon and deep space. In this project we will explore the use of a room temperature liquid metal, passively actuated in a channel, to connect or disconnect two thermal conductors, turning the switch ON or OFF, respectively. Compared current state-of-the-art technologies for passive heat switches, this technology enhances the structural integrity of the switch, as the conductors are stationary, with only the liquid metal plug moving within a pre-described channel. Overall, we expect this compact and light-weight thermal switch to achieve conductance ratios of at least 500 : 1 (up to 1000 : 1) over a large area at a full ON performance > 6 W/K.
Status: Completed
Description: Meteoroids comprising the sporadic background population continuously impact larger bodies in the solar system at high speeds. In particular, asteroids are subjected to hypervelocity impacts on their surface due to the lack of atmosphere, resulting in the formation of ejecta plasma. Based on interplanetary meteoroid flux models, a 1 km asteroid at 1 AU would encounter over 100,000 impacts per day from meteoroids larger than 1 nanogram (10 micrometers). This plasma is primarily composed of ionized material from the asteroid surface with only a small contribution from the impacting meteoroid (estimated to be 2% based on crater volume models), and provides a mechanism for characterizing the surface composition of the asteroid. We propose to develop a low mass and low power sensor concept to complement the spectroscopic analysis of an asteroid's surface composition by studying the transient plasma environment in its vicinity. This concept would enable rapid coverage of the asteroid surface using a cluster of nano- or picosatellites equipped with plasma sensors. As humans start to exploit the natural resources available on asteroids, the initial cost will be quite high. Accordingly, it will be necessary to demonstrate that resource extraction missions are targeted at sites of high return. This will likely involve lower-cost precursor missions to several potential asteroids before sending a mining or redirect spacecraft to the one with the most value. The concept presented here enables measurements to be made using multiple (on the order of 10 to 100) identical small spacecraft, and provides a greater coverage of the asteroid surface than with a single conventional spacecraft using more traditional instruments. The use of multiple spacecraft in a cluster provides a dramatic increase in the robustness of the system to single failures, with a gradual decrease in performance rather than complete loss of a particular capability. The plasma sensor is based on the concept of mass spectroscopy, which would provide a measurement of the asteroidal molecular composition rather than the atomic composition as measured through IR, X-ray, or gamma-ray spectroscopy.
Status: Completed
Description: <p>Ablative thermal protection system (TPS) materials are required for the extreme heating encountered during hypersonic entry into the Martian, Venusian, and Outer Planet atmospheres as well as for manned and sample-return missions into the terrestrial atmosphere. This proposal addresses the Topic 1: Advanced Thermal Protection Materials Modeling. Research pertaining to TPSs, specifically the ablative materials used for TPSs, remains one of the main focal points of NASA's technology development, with TPSs mentioned in 7 of 14 space technology roadmaps. The research proposed here is most closely associated with TA09: Entry, Descent and Landing. We propose to provide high-quality experimental data to support the development of high-fidelity, physics-based ablation models that include internal reactions and the chemical evolution of pyrolysis gases within hot carbon chars. Our primary objectives are to: (i) perform experiments with well-controlled test conditions and quantified uncertainties on all relevant test variables; (ii) conduct these experiments in a configuration that can be directly simulated by using coupled Fluid Dynamics (FD) and Material Response (MR) codes, and (iii) use the data in a high fidelity coupled FD/MR framework to extract parameters and validate models. We propose a 3-year research program to accomplish our objectives. We will investigate both internal oxidation reactions in partially dissociated air flows and the chemical evolution of representative pyrolysis gas mixtures by heterogeneous surface reactions with a hot char. Experiments will be performed in a furnace-heated, flow tube configuration, using a porous carbon material as a char simulant. We will regulate input mass flow rates, measure absolute and differential pressures across the porous specimen, and monitor sample temperatures. We will use a microwave discharge and chemical titration techniques to produce and quantify partially dissociated air flows and calibrated gas mixtures representative of incipient phenolic pyrolysis products to study the chemical evolution of pyrolysis gases. Gas compositions will be monitored as a function of temperature, pressure, and flow rate after they exit the hot carbon char simulant using a combination of advanced mass spectroscopic techniques. Changes in char density, permeability, and microstructure due to oxidative attack or carbon deposition by coking reactions will be documented and correlated with gas composition measurements. Scanning electron microscopy analyses of specimens prior to and post furnace heating will be implemented to characterize changes in the microscale morphology and chemical composition of the char upon carbon fibers/ pyrolysis gases interactions. We will use the data obtained through the experiments in a numerical modeling framework designed to simulate detailed coupling problems that involved pure flow and porous media. The framework couples a FD solver with a MR code through detailed mass, momentum and energy balance, which ensures that transport phenomena at the interface are captured. We will use the non-reacting experimental results to validate the coupling scheme and calculate the macroscopic parameters such as permeability, in porous modeling zone. Finally, we will assemble a finite-rate chemistry model using a volume-averaged technique for gas-surface interactions inside the porous chars. We will use the data to select and calibrate the kinetic rates. The benchmark data sets generated by this work are essential for modelers to construct and validate internal reaction and pyrolysis gas evolution models for high-fidelity ablation simulations. The outcome of this research will raise the Technology Readiness Level of the MR codes used for predicting ablation performance in real flight environments. The long term payoff for NASA will be a more sophisticated suite of MR codes with advanced flow field coupling capabilities for ablative TPS sizing.</p>
Status: Completed
Description: <p>The success of future lunar and planetary exploration missions will require predictive simulation tools that capture the complex multiphase dynamics associated with rocket exhaust impingement during touchdown. As a spacecraft approaches the surface of a terrestrial body, high-speed ejection of granular material results in scouring and dust impregnation of exposed hardware, reduced visibility, and potential spoofing of the landing sensors. However, existing modeling tools are unable to simulate these environments accurately. The key objective of this project is to develop advanced physics-based models and numerical algorithms to enable predictive simulations of plume-surface interactions (PSI) under relevant landing conditions. A multiscale approach is designed to connect the flight-scale landing model to two-phase statistics obtained from direct numerical simulations (DNS) that fully capture relevant microphysics. In addition, novel uncertainty quantification (UQ) techniques will be used to measure the effect of modeling parameters on key quantities of interest associated with plume-induced cratering and ejecta characteristics.</p>
Status: Active
Description: <p>This project is focused on developing high-performance transient liquid phase bonding strategies between Nitinol (a shape memory alloy) and dissimilar materials (e.g., steels and titanium alloys) to enable its use in extreme aerospace applications. The primary objectives of this research are to understand atomic diffusion during bonding, and ultimately control phase formation to produce strong and tough joints. In particular, this project will: design interlayer compositions, tailored throughout their thickness, to avoid brittle phase formation; determine interlayer formulations that minimize fabrication cost and bonding time; and, most importantly, demonstrate this process can be scaled to free-standing interlayer foils that are relevant for commercial use. The insights gained from this project can be applied to any dissimilar material joining (or layer-by-layer) process where intermetallic formation and cracking is a concern.</p>
Status: Completed
Description: <p>The goal of the proposed research is to characterize the influence of process parameter variability inherent to Selective Laser Melting (SLM) and performance effect on components manufactured with the SLM technique for space flight systems. Specific objectives are: To develop, verify, and validate robust physics-based numerical models for predictive SLM simulation using a DOE multi-physics, multi-scale massively parallel code called ALE3D for powder-scale SLM process simulations. To quantify the uncertainty in the prediction of material density and maximum tensile residual stress during laser melting and solidification of cubic coupons. A synergistic computational and experimental approach is proposed. The team assembled for this project includes J-P Delplanque (PI) and E. J. Lavernia (co-I) at UC Davis and collaborators R. McCallen, A. Anderson, and C. Kamath at Lawrence Livermore National Laboratory. The approach focuses on the melt-pool/powder-scale phenomena. A simple configuration (single track and cubic coupons) is considered. An uncertainty quantification strategy will be developed using PSUADE (LLNL) and surrogate models. Quantities of interest are: density and maximum tensile residual stress. ALE3D (LLNL) will be used to perform detailed numerical simulations. Laser melting experiments will be conducted to validate detailed numerical simulations and a surrogate process model will be developed on the basis of detailed numerical simulations. An important outcome will be a path to predictive numerical simulation of SLM processes and the identification of strategies to mitigate part variability. It is noted that the development of the surrogate model will also provide insight and guidance for the future development of reduced-order models and, in the longer term, process control strategies. The validation and uncertainty quantification methodology developed will be relevant to other additive manufacturing technologies (e.g., Direct Laser Deposition). The proposed work will constitute a cornerstone of the improved understanding of uncertainty quantification of the SLM process needed for the certification of components produced by these techniques. The proposed work will benefit from active collaborations between UCD, LLNL, and NASA ARC. Geographic proximity will facilitate regular meetings and provide ample opportunities for information exchange to ensure that the research is consistent with NASA’s needs and that it benefits from and complements ongoing efforts at NASA and LLNL. Existing collaboration between UC Davis and LLNL in the context of Accelerated Certification of the Additively Manufactured Metals initiative at LLNL will be leveraged. The proposed work directly addresses subtopic 2(a) of the solicitation (Uncertainty quantification for additive manufacturing). Since the outcomes will contribute to the development of model-based certification methods the proposed research is pertinent to Technology Area 12 (Materials, Structures, Mechanical Systems and Manufacturing) of NASA's Space Technology Roadmaps.</p>
Status: Completed
Description: <p>The proposed program develops novel sensing, perceptual models, and energy-efficient exploration strategies to enable mobile autonomous systems to explore icy moons and identify high value science targets. The research program will yield: (1) a novel active illumination sensor that can selectively image certain types of light paths while blocking others with the capability to scan optically challenging materials such as ice; (2) a probabilistic sensor model that accurately captures sensor measurements and incorporates intensity, depth, and material information; and (3) an energy-efficient motion planning framework that yields maximally informative and energy efficient trajectories that generalize across multiple mobility platforms. Integrative experiments will validate the developments at sites in Pennsylvania that exhibit similar characteristics as the anticipated craggy, icy environments. Each field experiment will emphasize in-situ evaluation and validation of the proposed approach.</p>
Status: Completed
Description: <p>This space technology research effort will develop photonic integrated circuit technology for deep space laser communications. Photonic integration is a method to integrate several photonic functions on a chip in a manner similar to integrating transistors in an electronic integrated circuit. Current space laser transmitters are assembled with discrete components, which is a cumbersome and costly process. Light is coupled to and from each component through fiber couplers, which introduce optical losses and potential failure points. Photonic integration eliminates these coupling elements by interconnecting components on chip while also significantly reducing the size, weight, and power of the laser transmitter. With this technology, entire laser transmitter systems can be realized on a single chip. The HELIOS project will evaluate the potential impact of applying photonic integration to deep space laser transmitters, and establish target specifications by working closely with flight transmitter experts at MIT Lincoln Laboratory and JPL. A library of high-performance photonic building blocks will then be developed. The vision is that system architects will eventually leverage this library to design integrated flight transmitters in a straightforward manner using circuit simulation and design tools. The library will contain fundamental building blocks such as lasers, optical modulators, and optical amplifiers, as well as blocks for performance monitoring including optical taps and photodetectors. Designers will be afforded the flexibility to configure devices for specific modulation formats, and customize laser designs for required output power levels. As such, HELIOS will innovate space exploration by providing a more compact, lower cost, more reliable, and higher performance solution for high data rate deep space laser communications.</p>
Status: Completed
Description: Advances in robotic technology have opened up an era of tremendous scientific discovery in planetary science within our solar system. While NASA has successfully landed multiple rovers on Mars, these robots require a human operators to monitor the rover’s status, analyze sensor data, and command or even directly teleoperate the robot under significant time delay. To harness the full potential of these robotic systems and enable true human-robot teaming, we propose to develop new computational methods for robots to better intuit the goals and strategies of their human counterparts and to understand when and how to act with more autonomy
Status: Active
Description: Using refrigerants in spaceflight applications can impose hazards, require leak monitoring and replenishment, and result in tight operational temperature constraints. Elastocaloric cooling is an emerging high-efficiency solid-state cooling technology that can remove these constraints. The technology is based on the elastocaloric effect, a thermodynamic phenomenon associated with stress-induced solid-state phase transformation, during which the working material may absorb or release a large amount of latent heat that can be used to pump heat. The project objectives aim to develop novel elastocaloric materials and a high-performance refrigeration system for NASA exploration applications. The project objectives will be achieved by a combined materials and system effort: 1) use the newly established computation/machine learning guided high-throughput bulk metals development methodology to unravel the complex relationships between compositions, crystal structures, phase transformation, and fatigue behavior of the elastocaloric materials. 2) leverage our team member’s spacecraft design and manufacturing expertise to design a novel cooling system that can take full advantage of the newly developed material for a most suitable spaceflight application.
Status: Completed
Description: <p>Soft robots (made of compliant or soft materials) are often perceived as less capable when compared to traditional rigid robots. However, the proposed work will show that we can have compliant robots that are effective when operating in uncertain conditions while still having precise, high performance control for manipulation and mobility. In order to dramatically improve control for soft robots, we will initially develop optimal control methods on a 14 degree of freedom, pneumatically actuated, fabric-based, light-weight, mechanically robust robot torso and arms. This system is underactuated and underdamped, and we expect that advances in control for this platform will translate directly to systems with similar dynamics. Furthermore, the resilience of this platform to unmodeled collisions will enable us, as part of our proposed research, to develop algorithms for collaboratively working with other soft robots or people in harsh environments such as space. The platform on which we are developing our algorithms is light-weight, relatively inexpensive, and can be compactly stored for transportation. The result of our proposed work will be a set of control algorithms that will improve the overall performance and relevance of soft robots for future NASA missions.</p>
Status: Completed
Description: <p>NASA's Asteroid Redirect Mission (ARM) is a pivotal and daring approach that will mature multiple technologies for future deep space exploration. ARM seeks to capture a near-Earth asteroid and return it to a stable lunar orbit where astronauts can explore and bring back samples from the asset. One process being studied to capture an asteroid, is to have the robotic craft land on the surface of a larger parent asteroid and use dexterous robotic manipulation to pickup a boulder from the surface and secure it for the transportation to lunar orbit. The Robotic In-Situ Surface Exploration System (RISES) proposed in this work aims to mature mining sensor technologies such as sonic wave velocity sensors and Schmidt Hammer technology to provide in-situ analysis of the asteroid material which, in turn, can aid the robotic manipulation/pickup procedure and an ISRU system by understanding the material strength and composition, respectively. The sensing capabilities of sonic wave velocity and Schmidt Hammer sensors on a scale relative to ARM (1-10m boulder/asteroid diameter) will be studied and the requirements to advance such technology in support of ARM and ISRU will be determined. The integration of the matured sensor system for ARM and ISRU will be integrated and tested on advanced robotic manipulator platforms which will utilize the robot kinematics for accurate position measurements between the sensor transducer and receiver. The testing will advance the TRL level of the RISES system and show the application to future NASA missions and objectives.</p>
Status: Completed
Description: <p>The desire to explore the surfaces of icy moons, such as Europa, will require the development of a new generation of planetary mobility technologies. Wheeled and tracked vehicles are not suitable for the icy and steep slopes that may be encountered, while hopping approaches are inherently risky when adequate terrain assessment is not possible. Legged vehicles provide a promising avenue for traversing complex terrains, however icy surfaces will require anchoring mechanisms to maintain a secure hold. This is especially true for traversing steep slopes or cliff faces that may be encountered. The proposed effort is to develop a novel claw end effector to capitalize on the unique characteristics of an icy moon with effectively no atmosphere. With an electrical heating element embedded into a claw tip, the claw would safely sublimate a hole into the ice, resulting in a relatively undamaged hold point to provide traction, even up a sheer cliff face. The objectives of the proposed effort are to characterize the power, mass and performance of such an end effector, as applied to water ice at cryogenic temperatures under vacuum, and to demonstrate the implementation of these end effectors by integrating them into a simple legged mobile platform to conduct a variety of climbing maneuvers using a dry ice terrain analog at atmospheric pressure.</p>
Status: Active
Description: <p>Through the use of solar-radiation-pressure (SRP)-based propulsion, solar sails offer unique mission capabilities, including orbits outside of the ecliptic plane and interstellar travel. Solar sail technology has advanced in recent years, and it is now conceivable that solar sails with areas of thousands of meters squared will be fabricated and deployed in the coming decades. An unsolved challenge in the design of solar sails is ensuring their attitude and momentum can be controlled accurately and reliably using technology that scales up to the size of these large, next-generation solar sails. To address this, we propose the Cable-Actuated Bio-inspired Lightweight Elastic Solar Sail (CABLESSail) concept, which leverages lightweight cable-driven actuation to achieve controllable elastic solar sail deformations that induce an imbalance in SRP and generate large, scalable control torques in all three axes.</p>
Status: Active
Description: Hypersonic entry vehicles such as capsules operate in an extreme environment where a plethora of physical phenomena must be understood and modeled to design thermal protection systems. Among these phenomena, the interaction between turbulence and chemical reactions in the gas is generally not well understood. This work will extend wall-modeled large eddy simulations (WMLES) to incorporate chemically reacting effects, enabling scale resolved simulations of chemically reacting turbulent flows. WMLES is attractive approach to turbulence modeling for hypersonic flows because it relies on fewer modeling assumptions than Reynolds Averaged Navier-Stokes (RANS), the current design paradigm, at a tractable computational cost not afforded by traditional LES. This work will advance our fundamental understanding of hypersonic chemically reacting flows and enable future improvements to the RANS models currently in use for spacecraft design
Status: Completed
Description: Several advanced thermal protection system (TPS) materials currently under development, such as conformal and woven systems, leverage the porous ablator technology developed for phenolic impregnated carbon ablator (PICA), a binary-constituent composite resin infiltrated carbon fiber substrate system. Current ablation models assume thermodynamic equilibrium chemistry to estimate the recession rate and temperature response, and these models are known to be deficient because they over predicted the recession rate, for example, during the Mars Science Laboratory entry into the Martian atmosphere. Clearly, non-equilibrium chemistry is important in such environments; therefore, non-equilibrium models must be built on a fundamental understanding of the relevant non-equilibrum chemical kinetics and dynamics, which may be obtained from in situ measurements of chemical processes during pyrolysis of PICA-class materials under controlled, non-equilibrium conditions. Validating the models with such high quality laboratory data will enable optimized risk and margin recommendations for a whole generation of future NASA and commercial space missions. The objective of this effort is to transform our understanding of the decomposition chemistry of carbon/phenolic composite ablator materials using advanced techniques that are well established in the field of reaction dynamics but have not previously been applied to understand the decomposition mechanisms of these materials in an atmospheric entry environment. To achieve the objective, we will measure time-dependent yields of volatile products during the pyrolysis of a phenolic resin and a carbon/phenolic composite, and we will study the kinetics and dynamics of the heterogeneous reactions of ablation products and representative boundary gases (from Earth and Mars environments) with char and with preform carbon surfaces. We will also investigate the erosion kinetics of pure phenolic resin and a carbon/phenolic composite at high temperatures in a simulated boundary-gas environment. The focus materials will be PICA, obtained from Fiber Materials, Inc., and the separate preform carbon and phenolic resin components of this composite. The experiments will utilize a molecular beam apparatus with a highly sensitive, triply differentially-pumped mass spectrometer. The mass spectrometer will be used to detect pyrolysis products of hot materials and reactive products when controlled material surfaces are bombarded with beams of specific reagent gases. Pyrolysis products will be detected from surfaces with temperatures from ambient to about 1500 K, while beam-surface reactive products may be detected from surfaces with temperatures up to about 2200 K. For kinetic studies of erosion, surfaces at various temperatures will be bombarded by beams containing pure O2, N2, or CO2 and mixtures containing O, O2, CO, CO2, N, and/or N2 in mole ratios to be specified. Exposed surfaces will be probed by scanning electron microscopy (SEM). The PI intends to work closely with NASA researchers to ensure that the experiments conducted will generate data that will validate ablation models under development.
Status: Active
Description: <p>Rechargeable batteries used in solar-powered orbital missions and Mars surface missions need to be engineered for extreme environmental conditions. Depending on the mission, the battery system may be exposed large vibration environments, radiation, and large temperature and pressure swings. The primary limitation with the current state-of-the-art is the temperature range (-20CC to 40C). This temperature limit is related to the liquid electrolyte's freezing and boiling point. Future missions require novel systems that can endure freeze-thaw cycles. This proposals intend to examine the fundamental science behind degradation mechanisms in batteries which are exposed to large temperature swings. In particular, this proposal seeks to examine the key limitations with wide-temperature range lithium ion batteries: interfacial transformations using advanced electrochemistry diagnostic tools and x-ray imaging. </p>
Status: Active
Description: <p>This project will design, manufacture, and characterize ultra-conducting copper nanocomposite wires for high voltage applications. Atomistic simulations and machine learning will provide optimal conductor designs. The theoretically designed structures will be fabricated, processed into a wire form, and characterized under lunar-relevant environment for high voltage power transmission (HVPT). The higher electrical conductivity of the proposed materials, compared with copper, translates directly to a lower HVPT cable weight or decreased electricity waste, significantly reducing resistive losses or weight. Therefore, developing ultra-conductors is of utmost importance for all NASA missions where weight and energy savings are at a premium, specifically for a sustained human presence on the moon. In addition to an enhanced conductivity per weight, the proposed copper nanocomposites will be more radiation-resistant, and their performance and integrity less affected by the extreme lunar temperature fluctuations.</p>
Status: Completed
Description: <p>The primary focus of this proposal is to examine the development of a new method of digital materials and manufacturing process to produce sparsely filled structures using a reconfigurable lattice. The proposed work will investigate the implementation of the concept, examining questions including design, fabrication, geometry, and planning issues related to the nature of achievable structures. The approach addresses a number of shortcomings in current additive manufacturing processes, including strength of materials, efficiency of material usage, energy-efficiency of the process, and reusability/reconfigurability of the base materials – all of which will lead to improved efficiency and facilitation of fabricating spatial structures, especially in remote locations where mass/volume of payloads is at a premium.</p>
Status: Active
Description: Achieving a successful soft landing on another planet is a challenging endeavor. The Entry, Descent, and Landing (EDL) phase of space vehicles lasts merely a few minutes, yet it encompasses the transition from hypersonic speeds with extreme temperatures to the safe touchdown. Despite the existence of computational methodologies for modeling the fluid dynamics surrounding EDL vehicles, the current approaches lack the capacity to perform accurately across multiple flow phenomena. To enable safe and successful planet exploration by NASA, we propose developing a computational fluid dynamics model that accurately predicts the flow patterns and thermal distributions around EDL vehicles at hypersonic speeds. The improved modeling capabilities will facilitate the development of future missions to Mars, Titan, and the gas giant planets.
Status: Active
Description: <p>Forthcoming space networks are expected to be multi-tenant with multiple service providers carrying bundle flows with differentiated classes of service. These requirements, coupled with a higher uncertainty of the resulting system state, e.g., worse contact communication conditions than initially expected or planned contacts that fail to realize, demand a revised approach to space delay-tolerant networking (DTN). The project objectives aim to enhance the routing capabilities of DTN gateways with situated artificial intelligence techniques, bringing (A) user-defined multivariable utility functions that become self-optimized via learning; (B) scalability through a continual adaptation to unplanned events and network topology changes; and (C) compatibility with the Bundle Protocol and non-cognitive, standard DTN routing regions. These capabilities are integrated with an open architecture and experimentally demonstrated. Outcomes of this work are expected to help increase space networking autonomy with levels of communication performance and efficiency well above what can be achieved today.</p>
Status: Completed
Description: Long missions in deep space present a new set of challenges for maintaining the health, safety and performance of crews. In particular, the ability to screen for disease, establish deviations from health, and detect viral or bacterial infections both in humans and in cabin air or water systems are essential requirements for assuring the health of crew members during flight missions. Many standard screening methods for analyzing, for example, protein and nucleic acids, are not ideal for space flight missions because they often require long processing times, are labor intensive and often use hazardous chemicals. The goal of this project is to is to utilize the electrokinetic method, isotachophoresis (ITP) to develop a liquid handling and sample acquisition technology that is capable of simultaneous extraction of both proteins and nucleic acids from human body fluids and cabin water. Because separation, concentration and extraction of both nucleic acids and proteins will be accomplished in a single step, the success of this project will lead to dramatic improvements in space hardware for monitoring human health. Objective 3: To demonstrate hardware capabilities with single-step sample loading and molecular extraction.
Status: Completed
Description: <p>The OSU and Raytheon Technology team will create and demonstrate a modular DC-Energy Router that not only can function as a power flow controller but also as an intelligent circuit breaker, thus realizing interconnections and power flow optimizations between multiple lunar surface power systems. During the project, the team will focus on energy routing and system stability enhancement, over current and fault current limiting, digital twin and model-predictive control, sensor placement optimization for system reliability, and concept validations with a 120 V, 10 kW prototype.</p>
Status: Completed
Description: The high variability and low repeatability of metal parts produced using Additive Manufacturing (AM) represent a major barrier in getting AM into the mainstream. Efforts to characterize (and eventually reduce) variability start by predicting the microstructure and performance properties of AM parts. In this proposal, we propose a Phase Field Modeling to characterize the microstructure evolution in Selective Laser Melting (SLM) given the temperature history. The majority of works in the literature focus on predicting the thermal history, and none of these works capture microstructure evolution. In contrast, we will experimentally characterize the thermal history using a custom integrated monitoring system, and then use Phase Field Models to computationally predict the microstructure of the fabricated part. Furthermore, we will capture one layer of uncertainty by modeling the temperature history as a time-based stochastic process with measurement errors. Next, we will conduct systematically designed experiments to validate the predicted microstructures, and identify key process parameters and higher order interactions that significantly contribute to the variability of the microstructure. The outcome of these experiments will be used to construct a Response Surface Model to optimize process parameters (e.g. laser power and scanning speed) such that we achieve desired properties while keeping variability at a minimum and increasing repeatability. The proposed framework will be validated using Nickel Titanium Shape Memory Alloys as a model material that is both highly applicable in aerospace applications and whose macroscopic properties are very sensitive to small variations in process parameters and microstructures. The key aspects of innovation in this project lie in proposing a phase field model-based novel approach to characterize microstructure evolution in SLM, and further integrating this with stochastic processes and uncertainty quantification models to identify and control variability sources. This will represent a major contribution to the existing literature on modeling SLM processes which solely focuses on predicting the thermal history. Furthermore, the outcomes of the project will be used to build a repository of process parameters and material properties for NiTi SMAs, and will contribute to increasing the MRL for the Selective Laser Melting of SMAs from its current TRL 1 to TRL 3.
Status: Completed
Description: Multi-robot teams aboard the Lunar Orbital Platform-Gateway will need to communicate with human teammates aboard the Gateway and with ground control workers permanently stationed on earth. Many aspects of these robots' communication strategies may be viewed as performative: robots may perform different levels of autonomy to build trust and rapport through transparency, and may perform different identities to control the localization of that trust to specific bodies and identities. Through the lens of performance of identity and autonomy, we will develop a better understanding of the impact of human-multi-robot communication strategies on the localization, dissociation, and fragmentation of human trust across different robot bodies and identities, and enable robots to maintain sensitivity to spatiotemporal distance when communicating, to build trust and rapport without cognitively overloading human teammates.
Status: Completed
Description: <p>For hypersonic atmospheric entry missions, charring ablators are often used. These materials are made of non-pyrolyzing matrices (carbon, ceramic, etc.) combined with pyrolyzing materials (phenolic, silicon resin). Pyrolysis is the process in which the polymer gradually carbonizes at high temperature, losing mass and generating pyrolysis gas. Once generated inside the matrix, the gas is expelled at the surface, changing the chemical composition of the boundary layer and influencing the thermal conductivity. The material models currently used for designing AVCOAT thermal protection systems (TPS) are based on models that were designed during the Apollo era. Although they have been updated to better replicate the behavior of modern-day AVCOAT, such as that used on Orion, they remain very similar to the original. Although these models have been adequate in providing analyses leading to successful missions, they they fail to account for specific physical processes; the results therefore lack accuracy, leading to higher safety margins for TPS.. The current proposal aims at using a statistical approach to redesign, from the ground up, the AVCOAT material model currently used by NASA. Using uncertainty analysis, the extensive AVCOAT arc-jet data will be thoroughly analyzed, and used to estimate the best simulation parameters. This new material model will then be applied to the EFT-1 flight data, and its accuracy will be assessed. As a second task, a new integrated modeling approach will be developed and tested. Contrary to the state-of-the-art which consist of coupling (loosely or not) a CFD code to a Material Response (MR) code, the new method proposes to solve the whole domain using one general set of equations for both the flow field and the porous ablator. This approach has the advantage of effectively removing all boundary layer assumption currently used in aerothermal boundary conditions by letting the code calculate the surface fluxes intrinsically, and not by imposing approximate surface balance equations.</p>
Status: Completed
Description: <p>Many quantum-enhanced technologies such as networked quantum computing, quantum-enhanced sensor arrays, and enhanced communication protocols rely on the distribution of quantum entanglement – an underpinning resource for most quantum technologies. A satellite-based source of entangled photons can be used to distribute entanglement to ground-based receivers. To realize a high rate of entanglement distribution in such a scheme there are several challenges that must be overcome, including realization of a high-rate entangled photon-pair source compatible with space-based environment, synchronization between source and receiver, channel loss, and reduction of background noise especially during daylight flyovers. Here we take a systems approach to design both the source and receiver to optimize the entanglement distribution rate. This is done by using temporal modes of light to encode information and matching the temporal modes of the transmitter-receiver pair. A key innovation here that makes this possible is the use of a coherent temporal-mode filter, the ‘quantum pulse gate,’ at the receiver. The matched source and receiver will be realized through careful design, fabrication and testing of thin-film lithium niobate devices and deployed as a transmitter-receiver system in the laboratory.</p>
Status: Active
Description: <p>Solar sailing offers unprecedented capabilities for space exploration enabling such missions as solar polar imaging and inner heliosphere probes, and fast transit missions to outer planets and interstellar medium. However, attitude control of present day solar sails is rather limited and cannot be easily scaled to larger and lighter sails. Here, we leverage advances in mechanical and optical materials to create an innovative metamaterial solar sail attitude control system. Our metamaterials are seamlessly integrated with the sail material and allow decoupling sunlight incidence and sail geometry, while creating torques in desired directions. The approach enables controlling local radiation pressure momentum transfer in both in-plane and out-of-plane directions. Equipped with the metamaterial control, lighter and more efficient solar sails can be designed. </p>
Status: Completed
Description: With the advent of the standardized CubeSat platform and continuous improvements in satellite imaging systems, massive constellations of orbital assets will soon provide us with global, real-time surface coverage. Multiple companies are already preparing or launching constellations for commercial purposes, including persistent surface monitoring and providing internet services. Such constellations are also perfectly suited for NASAs mission of exploration and discovery, both for studying the Earth and other solar system bodies. However, current techniques for satellite sensor cross-calibrations scale poorly to constellations of hundreds of elements. Furthermore, current constellations require significant data processing on the ground, which imposes delays on detecting and following up on events of interest. Fully autonomous onboard processing would provide unique and invaluable opportunities to study transient phenomena. To address all these issues, we propose an autonomous cross-calibration scheme for space-based imaging platforms based on an optimal observer combining measurements from standard sources, such as GPS and onboard attitude determination systems, with invariant features extracted from the satellite imagery itself. By sharing individual state estimates and features between elements of the constellation, individual spacecraft will update their own state estimates, which will include both position and orientation knowledge as well as the complete geometric calibration of their imaging system. Continuous state estimation will enable imaging products to be downlinked with sufficient metadata to allow for sub-pixel co-registration without additional fitting. At the same time, temporal changes in the feature set related to a particular location on the ground will reveal transient events that can be autonomously monitored by multiple constellation elements, or by other sensing platforms.
Status: Active
Description: Space debris poses an increasing risk to the operation of satellites and spacecraft, especially in low Earth orbit. Collisions, whether between debris and operational craft or between debris objects themselves, threaten to damage critical space systems and further increase the debris population. While traditional remediation techniques focus on removing large, high-risk objects from orbit, Just-in-time Collision Avoidance (JCA) strategies aim to dynamically lower overall risk by taking small, last-minute actions—slightly nudging the orbit of a debris object, for example—to prevent predicted collisions. We propose to develop a new JCA architecture based on deployment of dust clouds from orbital platforms in order to provide small braking forces on targeted debris objects, providing a responsive, always-ready method to prevent high-consequence collisions.
Status: Completed
Description: The objective of the proposed work is to improve NDE state-of-the-art for detection and identification of manufacturing and service-initiated defects in CFRP composite structures. The work will utilize computational models of the interaction of NDE probing energy fields with the composite structure and the imbedded defect, to study 1) the measured signal dependence on material and defect properties (forward problem), and ultimately, 2) the assessment of performance-critical defect properties from analysis of NDE signals (inverse problem). Generally speaking, the forward problem is mathematically well-posed, amenable to a well-established array of computational approaches, whereas the inverse problem is by-and-large ill-posed, and in need of novel conceptual development leading to robust meaningful solutions. Regarding the forward problem, computational models will be employed appropriate for simulation of NDE measurements in potentially large complicated geometry composite laminate structures. Work will primarily address ultrasound and thermography NDE modalities. A premise of the work is the availability of computational models capable of predicting measurement response for specified NDE measurement instrumentation systems, composite structures, and embedded defects. CNDE has in place computational models for a large relevant class of structural configurations, and is poised to further enhance current simulation capabilities as the proposed research requires, reflecting NASA’s interests. This simulation capability provides the infrastructure for handling the forward measurement problem. Regarding the inverse problem (i.e. the determination of flaw characteristics through analysis of measured signals), work will seek to constrain the ill-posed data inversion through optimization of supplemental measures of defect properties. While measured data is usually insufficient to uniquely determine the defect properties (size, shape, and constituents), a large percentage of solutions compatible with the limited measured data are inconsistent with physical properties of actual defects (e.g. the defect must be contained solely within the structure). The proposed research will explore the effectiveness of various quantitative measures of defect properties in constraining the ill-posed inversion, and the possibility of formulating measures capable of discriminating between flaw types of particular interest (e.g. ply delamination versus distributed porosity) when applied to Bayesian estimation of defect properties using limited measured data. The effectiveness of the computational models will be benchmarked against experimentally measured signals in composite structures containing defects possessing known properties. The computational tools will facilitate the design of NDE inspections, so as to provide an effective balance of defect sensitivity and efficient large area coverage. Although explicit demonstration will be limited primarily to ultrasound and thermography, the concepts emerging from the proposed work will be applicable to a broad range of NDE modalities.
Status: Completed
Description: <p>One of the key questions about lunar ice and regolith is what the spatial distribution and concentration of ice is and what the geotechnical properties of the regolith and ice mixture are. This project will combine dual percussive cone penetrometers with heaters and sensors based on a modified version of the TRIDENT drill stage from Honeybee Robotics. This allows geotechnical property measurements and differential calorimetry measurements to identify and quantify volatile content. The Percussive Hot Cone Penetrometer (PHCP) spot tests will be able to measure volatile composition and concentration in the test locations. Combined with high frequency ground penetrating radar to determine layers and continuity of the subsurface over large areas, this will allow horizontal and vertical spatial distribution measurements and identification of volatiles in the top 1 meter with a resolution of 0.1 wt% at 10 cm intervals as well as determination of geotechnical properties where PHCP spot tests are done.</p><p>Research will consist of measuring thermal release profiles of cryogenic volatiles in regolith, ground penetrating radar (GPR) calibration of subsurface ice and layering detection, developing the differential calorimetry instrument and integrate it with the percussive penetrometer, testing and selecting the best cone geometry for geotechnical property determination, laboratory, Dirty Thermal Vacuum Chamber (DTVAC) and field tests at Michigan Technological University and Honeybee Robotics of the PHCP and GPR to achieve TRL-5 or 6 by the end of the project.</p>
Status: Completed
Description: <p>Constellations of CubeSat radiometers offer enormous potential for Earth and Space observations as low-cost platforms with significant advantages over single, large and expensive monolithic systems such as real-time measurements with large coverage, resiliency of a distributed observation system, and graceful degradation with low-cost replenishment. On the other hand, to obtain stable and accurate calibration of individual sensors in the constellation, as well as precise calibration of the entire constellation to ensure uniform, consistent, and spatiotemporally continuous measurements are some of the main challenges in utilizing such constellations. To address these challenges, the proposed research will develop a framework called Adaptive Calibration of CUbesat Radiometer Constellations (ACCURACy) to calibrate CubeSat radiometer constellations in real-time via a novel approach by considering constellations as single systems to calibrate in their entirety.</p>
Status: Completed
Description: Calibration ensures that the measurement data are used appropriately and is critical for space missions which demand high-level accuracy, precision, and resolution over a long-term use. This project aims to enable autonomous space sensor calibration, both individually and collectively as a sensing network. We are particularly interested in applications of planetary observations and explorations when satellite constellations are used. The algorithms developed in this research are fundamental and will lead to computationally efficient, adaptive, and robust learning methods that can be used for many space applications. The proposed principled Bayesian framework to learn the models, fuse the information with uncertainties, and generate optimal decisions will advance the state of the art in uncertainty quantification, numerical analysis, and control theory.
Status: Completed
Description: <p>WRANGL3R – Water Regolith ANalysis for Grounded Lunar 3d Reconnaissance – is an ultra-compact laser spectroscopy system equipped with a fiber optic sensing probe that is embedded in a drill bit. WRANGL3R includes (1) a rotary-percussive drill with a hollow drill stem (1 m length, 25 mm diameter); (2) a novel miniature (<5 mm diameter; <50 mm length) optical probe to perform in-situ Laser Induced Breakdown Spectroscopy (LIBS); (3) automated water-content quantitative analyses routines, combining hardware designs and deep learning algorithms to enable unprecedented measurements: rapid, direct, depth-resolved downhole quantitation of water content while drilling.</p><p>Mounted on a small rover, WRANGL3R enables in-situ 3D mapping of water content on the Moon surface and subsurface directly with low detection limits (< 1 wt%) and low spatial resolution (< 1 cm depth resolution).</p><p>Our R/R&D effort will combine, for the first time, drilling and laser spectroscopy into an integrated tool. Each partner contributes complementary know-how and expertise: (1) Lunar science and spectroscopy by Washington University in St. Louis; (2) Design and development of high-TRL lasers and spectrometers and relevant resource exploration R&D by Impossible Sensing.</p>
Status: Active
Description: <p>Next generation space telescopes and instruments, such as those needed to directly image Earth-like planets orbiting Sun-like stars, increasingly rely on extreme dimensional stability. The stability of a space structure is directly tied to its constituent materials’ coefficient of thermal expansion (CTE), elastic modulus, and creep rate. This research focuses on designing, building, and testing high-modulus composite materials whose CTE can be precisely and permanently adjusted after fabrication. Ultrafast lasers are used to bond composite layers together, and to tune the CTE by adjusting the layers’ stiffnesses. Ultra-stable composites may provide the extreme stability needed for future large space missions and reduce complexity of other systems such as thermal control. </p>
Status: Completed
Description: <p>We propose to overcome the limitations of wheeled surface rovers by combining recent advances in ball-shaped soft-robots based on tensegrity structures (a tension network of rods and cables), with a hopping mechanism based on cold-gas thrusters. The ball-shaped tensegrity robot with a payload suspended at its center can be collapsed into a small deployment volume, be light-weight, and navigate difficult terrain. In addition to be capable of rolling dynamically (by actuating its cables) and to survive significant landing impact shocks while protecting a delicate payload, we propose to dramatically increase the mobility of this design by adding a simple gas thruster located near the center payload, so that the robot can quickly cover a 1 km distance over a series of hops, while protecting its payload at the center of its structure. Once it has hopped close to its destination, the robot can roll to its exact target. For this concept, we propose to study three technology areas: 1) Mobility - allowing safe and accurate positioning of the robot with a combination of cold-gas thrusters and precision rolling, 2) Perception - placement of sensors to allow for robust navigation, and 3) Autonomy - control algorithms allowing for robust hopping and precision rolling mechanisms that can automatically overcome unexpected obstacles and failures. The innovative tensegrity-based surface probes have much potential in accurately deploying small payloads with speed, robustness and at costs unmatched by today's systems. Tenegrity probes can facilitate an intriguing low-cost exploration mission profile: 1) A tensegrity probe can be squeezed into a small cargo volume then automatically spring away from a base rover; 2) Once released, the tensegrity probe can use a simple gas thruster to make a series of hops towards a final destination. 3) An active tensegrity structure can be used to orient thruster. 4) Compliance of structure allows probe to ``bounce'' on impact, protecting the payload; 5) The probe can then reorient itself from landed position without addition reorientation hardware and efficiently move from landed position to perform sensor measurements and deliver payload; 6) It can survive significant falls and is resistant to being stuck, simplifying route planning and allowing for more aggressive maneuvering and increased autonomy. While tensegrity-based probes have the potential to dramatically increase performance and science return of robotic planetary probes, significant early stage technology development is still needed to enable and evaluate this technology for planetary missions. We propose to develop three key areas to enable this mission concept. These areas will be defined within a reference mission of safely delivering a 1 kg payload a distance of 1 km on the moon. 1. Define thruster and hopping profile to safely deliver payload: The unique tensegrity design offers a number of different ways that the mission goal can be completed. We propose to investigate what thruster hardware will be needed for such a mission to succeed. In addition we will investigate several forms of hopping, ranging from long hops, cushioned by reverse thrusters to many short hops. 2. Determine controls needed to orient thruster and navigate effectively: The design of this probe calls for significantly different controls than for a standard gimbaled thruster. Our thruster will be located within the probe and may be partially or fully oriented by changing the shape of the tensegrity. We propose to research how to develop controls that allow successful completion of the reference mission. 3. Characterize performance using simulation and hardware prototype: For a robot probe to have broad applicability, it will need to handle many challenging terrains, such as hills, and craters. We propose to simulate the tensegrity probe in a number of terrains and simulate its mechanical properties of hardware to show the practicality of this concept.</p>
Status: Completed
Description: <p>We will prove the key technical components of an ISRU facility that can potentially beneficiate hundreds of tonnes/yr of volatile material from small carbonaceous asteroids and process this material into H2O, CO2, hydrocarbons (e.g. methane) and LOX propellant. This proof of concept will allow humanity to confidently develop propellant and materials processing plants and depots at the top of the Earth’s gravity well. A key motivation is to enable human missions to Mars or the Moon to launch with less propellant, water, and oxygen than currently required. Crewed exploration missions will be supplied at the depot and depart with full tanks, dramatically reducing the cost of exploration and development of the solar system and proving that humans can "live off the land" in space using asteroids as feedstocks. This concept is motivated by the need for extremely lightweight, practical, and inexpensive ISRU that once developed can be used on NEOs in the size range of ARM targets (or pieces of ARM targets) in a micro-g environment. This concept makes maximum use of thin-film capture and enclosure mechanisms (like ARM) for material processing; low-pressure thin-film inflatable solar concentrators for the lightest possible, high-quality solar thermal power; deployable thin-film sun shields for cold traps and temperature control; and material processing systems without significant electronics, robotics, complex mechanisms, or mechanical components. Our proposal will provide design concepts that show how small Diaphanous Systems can be used to capture and contain small asteroids, pyrolytically devolatilize large quantities of water and carbon dioxide, separate the extracted volatile constituents, and store them at a depot as useful resources for exploration and industry. Although some system components are currently at TRL 4 or above, the use of these components in a light-weight, practical design to extract and process volatiles from an asteroid is currently at TRL 1-2. Our focused research program will advance the concept to TRL 3. We will do this by building a sub-scale laboratory apparatus that simulates the effect of a solar thermal furnace on small, unprocessed samples of carbonaceous meteorites, then on small samples of asteroid simulants, to validate their similarity to the target meteorites, and then on larger (meter-scale) carbonaceous asteroid simulants. Our proposal will cite scientific work proving that pyrolysis can thermally devolatilize H2O from carbonaceous meteorites at #250C and CO2 at #600C. We will extend that work to engineering applications of how the materials are preprocessed and perform the experiments in a spacelike environment in a vacuum chamber. We will show how solar thermal surface heating propagates through asteroidal material, how the porosity and friability of the asteroidal material affect the out-migration of volatiles, and the degree to which applied mechanical shock and/or other mechanical processing is needed to enhance gas transport. Our team is led by Dr. Leslie Gertsch, Deputy Director, Rock Mechanics & Explosives Research Center at Missouri University of Science and Technology in an industrial partnership with ICS Associates Inc, and its Chief Engineer, Dr. Joel Sercel who will provide systems engineering and mission perspective. Our technical advisors include Mr. Robert Mueller of KSC who will provide linkage to NASA programs; Prof. Robert Jedicke of the Institute for Astronomy, University of Hawaii, an expert on orbit distributions, sizes and origins of NEOs; and Dr. Alexander N. Krot, faculty researcher at the University of Hawai’i and expert on meteorite mineralogy. NASA Technology Area: 7</p>
Status: Completed
Description: <p>The goal of this project is to reduce the power required for high bandwidth, deep space laser communications systems. Our concept will encode data in the time delay between short pulses of light. This technique, known as Differential Pulse-Position Modulation (DPPM), requires a low average power if the amount of data encoded in each delay is large, because each generated laser pulse then signifies a large number of bits. We will use a high precision clock to divide time into very small intervals (~ 0.1 nanoseconds), which will allow us to maintain high data rates (10-100 Mbits/second). We will demonstrate this technique in the lab and package it into a miniature optical communications instrument, designed for small spacecraft or any spacecraft where the mass and power are very constrained. The DPPM modulation scheme will be driven by a low power, space grade FPGA-based modem with time provided by a chip-scale atomic clock. The FPGA modulator will drive a pulsed laser system in a Master Oscillator Power Fiber Amplifier configuration that will emit energetic pulses of 1550 nm laser light. The instrument will be designed from the ground up to be adaptable to a wide range of communications and power requirements and efficient so that it can be demonstrated in space on a low-cost nanosatellite in the future.</p>
Status: Completed
Description: <p>Nuclear power and propulsion systems will enable future NASA human exploration of Mars, effectively decreasing transit time and reducing astronauts’ exposure to hazardous space radiation. For these systems require radiators for rejecting waste heat into space could be large and massive. These radiators need to be much lighter than current State-of-the-Art (SOA) and operated at higher average surface temperatures (~500-600 K). This project aims to develop a lightweight and foldable heat pipes radiator panel for heat rejection at these temperatures with a specific mass < 3 kg/m2 and higher resilience compared to SOA. The radiator panel will employ Ti / C-C composite rubidium heat pipes with integrated fins of composite C-C / Ti /Highly Oriented Pyrolytic Graphite (HOPG) for strength and effectively spreading rejected heat along the surface. The strong and lightweight C-C outer layer provides structural strength and serves as a protective armor against impacts by micrometeorites and space debris. The radiator panels have integrated C-C armored Ti-walled headers with perforated dividers to reduce pressure losses of the circulating NaK-78 fluid and facilitate uniform heat transport by the radiator’s rubidium heat pipes. Performance and structural analysis of the advanced radiator panel design will be carried out using multi-physics, multi-scale approach combining transient heat pipe simulation, 3-D thermal and Computational Fluid Dynamics (CFD), and structural analysis codes. This is in addition to conducting experimental characterization of the robustness of the interfaces in fabricated samples of the layered Ti / HOPG and Ti / C-C composite structures. Experimental testing will investigate the effect of temperature on the integrity of fabricated samples in inert gas atmosphere as well as in a high vacuum. This research effort will develop an optimized design of lightweight heat rejection radiator that ensures long life, suitable materials compatibility, and high structural strength.</p>
Status: Completed
Description: <p>NASA missions on Mars and the Moon require materials that can perform in extreme environments. Shape memory alloys (SMAs) meet this need in solid-state actuators and advanced structural pseudoelastic applications. To fully exploit these technologies, however, SMAs need to be joined to other SMAs and conventional materials without sacrificing the high-performance nature of the material. This research features a novel approach of joining these SMAs without altering the properties of the joined materials by using gas dynamic cold spray deposition, which is a solid-state additive manufacturing (3D printing) process. Cold spray joining of SMAs will provide lighter-weight joints while maintaining robust joint integrity; thus, providing cost savings by reducing payloads.</p>
Status: Completed
Description: <p>The objective of this proposal is to design and demonstrate an ultracompact opto-electro-fluidic system that can efficiently preconcentrate and separate low-abundance chiral molecules for in situ life detection. To achieve the objective, I plan to accomplish three specific research aims: (1) demonstrate an electro-fluidic preconcentrator for low-abundance molecules, (2) demonstrate an opto-fluidic separator for enantioselective separation of chiral molecules, and (3) integrate the preconcentrator and separator into a single ultracompact system and test its performances. With its superior performances, the proposed system will become an integral component for the future end-to-end in situ instrument for NASA space science missions. It will also benefit drug screening, drug purification and point-of-care biomedical applications in human space exploration.</p>
Status: Completed
Description: <p>Sustained human presence on the Moon requires advances in mission-enabling cables and wires to realize a lunar electrical grid. The lunar environment presents challenges such as exposure to cosmic and UV radiation, extreme temperature deltas, and the electrostatic lunar exosphere and regolith. The electrical performance of high voltage power transmission (HVPT) cables is closely associated with the properties of the cable insulation. Modern polymeric insulators employed in cables on Earth and aeronautic wires fall short of the requirements for the electrical microgrid to operate effectively in a lunar environment. We propose a study on lightweight, multifunctional nanocomposites that will simultaneously act as an insulation and shielding layer. We will focus on improvements in thermal conductivity, dielectric strength, electromagnetic interference (EMI) shielding, and mechanical strength of insulating polymer nanocomposites tailored to the demands of the lunar environment. The successful completion of this project will lead to dramatic improvements at the system level of performance, stability, and lifespan of current HVPT technologies. </p>
Status: Active
Description: In this project, we aim to architect novel ionic liquids with specific thermal properties beyond the limits of known heat transfer fluids, thus pushing the boundaries of performance for state-of-the-art thermal control subsystems. Early investigations of thermophysical properties of known ionic liquids show tremendous promise for their application to active thermal control technologies, although an optimized combination of ionic species has yet to be discovered. Here, we will leverage machine learning to enable the discovery of ionic liquids for spacecraft thermal control in the extreme thermal environments encountered beyond the Earth’s orbit, such as those of the lunar surface and deep space
Status: Completed
Description: The ability for humans and robots to accurately and effectively perform collaborative tasks is highly dependent on the efficiency of bi-directional human-robot interaction. Language is an important mode of communication for collaborative human-robot teams because it does not require line of sight and is capable of communicating high-level constraints and objectives of a task, low-level actions that a robot or human must perform, or observations that may inform a teammate’s model of the environment. Efficient algorithms and models for grounded language interaction are particularly important for space exploration because computational resources are limited, operations are often interdependent, and interactions may be intermittent. Recent models for efficient natural language understanding and generation based on approximate probabilistic inference exploit conditional independence assumptions across constituents of the symbolic and linguistic representations and learn from corpora of examples that map language to symbols in the context of the perceived environment. While such work has improved the efficiency of grounded language communication, the ability to effectively communicate how the algorithm reached the final distribution remains a significant and important challenge. A more advanced model for natural language communication should be able to explain why inference failed to ground a particular concept or provide bounds on the metric and semantic state of the world for which a symbol will remain valid. This is particularly important for verifiable natural language understanding, since verifiable execution of the synthetized state machine is based on the formal representation of the problem generated by probabilistic inference. This research will investigate new models and algorithms for natural language understanding and generation for explainable and verifiable human-robot teaming that provide new mechanisms for interacting with natural language symbol grounding models and enable more efficient and effective collaborative task execution.
Status: Completed
Description: The goal of the proposed work is to validate an initial design for a Europa penetrator that can withstand the high g load associated with the expected hypervelocity impact and enable post impact telemetry data. The proposed system would consist of a two-stage penetrator entry. The first stage would have the hard impact into the solid ice. Any deorbiting motors would be attached to the lead stage and add to the total mass involved in the initial impact. The second stage which carried the necessary electronics, would separate prior to impact from lead section. Because of the initial impact, this 2nd stage penetrator will experience less deformation and achieve greater penetration. As a result the mass of a two-stage system could be in fact less than a single stage system because less reinforcing will be required. To validate the system the proposed work will include (1) RAM accelerator studies to quantify ice penetration and changes in the property of the ice including subsurface fracturing as a function of shape of the projectile, temperature of the ice, and a 2nd impact; (2) calibrate a simulation model with these results to identify simulant material that will behave in a similar fashion as ice at the proposed speeds and then use these simulations to predict the behavior of the full size penetrator system against the simulant material; (3) field test a full size prototype based on the simulations in the high speed (< 1 km/s) regime but modified to take into account differences associated with the hypervelocity impact regime and (4) undertake a preliminary design for the survivability of key electronic components from the impact and their continued operation in the low temperatures of Europa.
Status: Completed
Description: Improved passive heat switch technologies would allow thermal engineers to maintain vital spacecraft components at their operating temperatures without consuming onboard power. The proposed passive magnetic heat switch will utilize temperature-dependent magnetic forces to bring thin-film permanent magnets in and out of physical contact, leading to large changes in the thermal conductance with compact switch geometries. The ultimate goal of this research is to demonstrate the thermal capabilities of high-performance magnetic heat switches, in order to enable future advances in spacecraft thermal control systems.
Status: Active
Description: <p>The extreme range of temperature oscillation (50 K – 350 K) in the lunar environment poses unique challenges to lithium-ion batteries, which need to hibernate during the lunar night (50 – 90 K, 354 hours) and recover at lunar dawn. Recent studies have shown strong evidence that lithium-ion batteries can potentially survive the cryogenic freeze-thaw process. We propose to perform chemical, mechanical, and electrochemical characterizations on custom lithium-ion cells on a precision temperature stage that can be interfaced with various spectroscopic instruments. The study will allow us to understand fundamental microscopic processes that occur within a lithium-ion battery during extreme temperature transitions with timescales relevant to the lunar environment. The insights gained will help predict the performance, degradation mechanisms, and thermal management strategies for lithium-ion batteries in the lunar environment.</p>
Status: Completed
Description: <p>“Soft” machines and electronics contain little or no rigid material and remain functional under large elastic deformation. Because they are soft, lightweight, impact resistant, and collapsible, these technologies have the potential to revolutionize robotics for human-machine interaction and space exploration. In this project, my research team and I will accelerate the application of soft machines to space robotics by introducing a “soft robotic tissue” composite embedded with soft elastic sensors, circuit wiring, rigidity-tunable elements, and actuators. These general-purpose elastic films will be millimeters thick and cover a large area. Because the films are soft and stretchable, they can conform to any shape or volume without exerting mechanical resistance. When integrated into clothing, soft robotics, or collapsible structure, the elastic composites can function as “artificial” skin, nervous tissue, or muscle. Potential applications range from strain, pressure, and curvature sensing for shape and contact detection to compact actuators that enable mobility and manipulation without reliance on bulky motors, transmission systems, or pneumatic hardware.</p>
Status: Completed
Description: <p>This project aims to advance design rules and fabrication approaches to create aerospace-grade structures from digital composite materials. Digital materials are discrete building blocks that can be assembled in a scalable, rapid, and reversible manner. To date, however, demonstrated structures have primarily been restricted either in the use of high performance composite materials or in the topology of the assembled structure. We will address these shortcomings via computational and experimental investigation of 1-D fiber-reinforced struts that have increased specific stiffness and buckling resistance, and 2-D element populations to create structures with tunable and directional properties. The modular design of digital materials will be modeled and characterized in an effort to avoid costly and lengthy sub-component certification. Ultimately, the ability to repurpose defunct space structures through disassembly and subsequent assembly within a new, modular design will provide greater material efficiency and a more sustainable launch cost structure.</p>
Status: Completed
Description: <p>There is a sustained effort to develop super-lightweight composites by using polymer impregnation of carbon nanotube (CNT) sheets. This promising area is still in its early stages and significant progress is required before CNT-based composites can be used in load bearing aerospace structures. Researchers from the University of Minnesota, Rensselaer Polytechnic Institute, and Skolkovo Institute of Science and Technology in Moscow will develop a broad scope multiscale modeling methodology able to simulate the mechanics of these materials. A mesoscopic distinct element method will allow for simulations of massive fibrous ensembles not only through parallel computing but also through efficient coarse graining of the atomistic scale interactions. This development will accelerate progress by providing the ability to guide experimental design through simulations.</p>
Status: Completed
Description: <p>Future lunar landers that will deliver humans to the Moon require the construction of landing pads. Yet, the lunar surface is marred by impact craters and impact debris that must first be cleared before a pad can be built. The Autonomous Site Preparation: Excavation, Compaction, and Testing (ASPECT) Project will develop tools and methods to clear, level, and compact the lunar surface. ASPECT is a fully autonomous rover with equipment for regolith excavation, boulder moving, and surface compaction.</p>
Status: Active
Description: A novel and versatile spacecraft coolant capable of efficient operation in various temperature extremes would be a game-changer for future space missions to challenging conditions such as frigid lunar nights, low-power intervals, extended interplanetary journeys, or high-temperature conditions near the sun. Ionic liquids, a novel category of purely ionic substances resembling salts, emerge as a favorable option for spacecraft cooling due to their potential to maintain a liquid state across a wide temperature span. Using a physics-based systematic approach, we aim to create suitable tailored ionic liquids and binary or tertiary ionic liquid mixtures to serve as a spacecraft coolant that could simplify spacecraft design and reduce overall system mass, resulting in lower launch costs and increased payload capacity.
Status: Active
Description: Accurate prediction of aerodynamic heating of space vehicles in hypersonic flight during atmospheric entry, descent, and landing (EDL) is paramount to the success of future space missions. Transition between laminar and turbulent flow regimes in the thin layers of fluid near the exposed surfaces of space vehicles critically increases the heat transfer that must be dissipated by the spacecraft’s thermal protection system (TPS). The proposed research aims to characterize the effects of surface roughness, freestream turbulence, and surface mass flux on laminar-to-turbulent transition and heat transfer augmentation in hypersonic flows over blunt bodies via high-fidelity numerical simulations, enabling accurate and feasible predictions through novel modeling approaches
Status: Active
Description: <p>Enabling the future of large telescopes and space structures NASA envisions for the discovery of habitable exoplanets require dimensionally stable lightweight structural components. Innovating advanced composite materials with exceptional mechanical properties and thermal stability is critical to achieve dimensional stability and robust functionality in extreme environments. Our research focuses on the computationally guided design, scalable fabrication, thermo-mechanical characterizations, and prototype demonstration of lightweight structured composites with extreme mechanical and thermal properties. We aim to identify and establish clear process-structure-property relations in nanofiber-reinforced composites with high-performance interphases that will allow us to overcome material property conflicts to achieve ultra-high modulus, -strength, and -toughness, and ultra-low coefficient of thermal expansion and creep rates.</p>
Status: Completed
Description: <p>The objective of this project is to develop a Piezoelectric Instrument for Precision Exploration Sampling (PIPES). PIPES is a miniaturized liquid sample acquisition and handling system, which looks like a straw and is powered by a hand-held box. The “straw” contains multiple flow paths for parallel sampling. Enabled by 3D printing, PIPES integrates acoustic actuation to achieve multiple sampling functions, including pumping, filtering, and mixing, in one compact unit. The PIPES system seeks to fill a gap in NASA’s current in-flight sensing capabilities: the lack of miniaturized fluidic sampling and handling systems. The PIPES will make dramatic improvements at the system level in terms of weight, cost and operational simplicity. Moreover, as a versatile micro- to meso-scale fluidic sampling system, the PIPES can work with multiple meso- and micro-scale detection technologies such as electrochemical sensors, micromachined chromatographs and miniature mass spectrometers. Therefore, PIPES has great crosscutting potential in biomedical and environmental applications.</p>
Status: Completed
Description: The University of Vermont (UVM) and the University of Michigan (UMI) propose a 2-year experimental and numerical research effort aimed at providing critically needed information on the state of pyrolysis gases leaving a porous char material for a carbon/phenolic ablator and reacting with hot boundary layer species. This proposed activity directly addresses 1) finite-rate gas-surface interactions; 2) finite-rate chemistry of pyrolysis and boundary layer gas interaction; and 3) resin decomposition. The experimental approach for these elements is the use of species-selective, laser-spectroscopic measurement techniques to quantify the chemical composition and thermal state of the gases as they leave the char surface and interact with the plasma boundary layer. The justification for addressing these elements is the lack of such experimental data to guide model development. The proposed experiments involve exposing selected carbon/phenolic material samples to high-temperature plasmas with varying composition (argon, nitrogen, oxygen, and air) in the UVM 30 kW Inductively Coupled Plasma (ICP) Torch Facility. During the tests the interaction zone will be probed using tailored, time-resolved Diode-Laser Absorption Spectroscopy (DLAS) and emission spectroscopic instrumentation. These experiments will establish which species leave the material, and how the composition varies with the introduction of different reacting plasma species (Ar, N, O). A parallel experimental effort will be devoted to developing novel sample test configurations that provide a constant char surface location in the plasma stream by allowing sample movement within the holder. The objective of this work is to establish quasi-steady test conditions to enable spatially resolved Laser-Induced Fluorescence (LIF) measurements of key species. Computations performed by UMI will support the development of this capability by simulating the experimental configuration and test conditions using state-of-the-art numerical codes that include pyrolysis and plasma species interaction chemistry. UMI has direct prior experience of simulating the flow in the UVM ICP Torch Facility. These simulations will help define test configurations and conditions as well as provide continuous feedback on experimental findings. The proposed investigation addresses three of the physical processes of Topic 1 with a set of carefully designed experiments that take advantage of existing laser spectroscopic instrumentation to quantify concentrations and gradients of key reacting species: O, N, H, C, CN, CH, OH. Based on prior work some of these measurements determine surface reaction rates, but in all cases the data will provide a valuable resource for validating the chemistry of advanced ablation models. These validation data sets will be comprised of in situ measurements of key species within the non-equilibrium reaction zone, along with carefully measured plasma test conditions and uncertainty estimates for all measured values. This will facilitate the development of better ablation models, which, in turn, enable more reliable and better-understood heat shields, leading to increased payload and/or mission flexibility.
Status: Active
Description: This research proposes a novel ADR concept using a network of reconfigurable space-based lasers for rapid response debris removal. A network of optimally placed multiple space-based lasers can cover a large volume of space at high spatiotemporal resolution as an inherent feature of a distributed multi-platform system. In addition, the space-based lasers can be closely coordinated to precisely control debris' deorbit/nudge trajectory, minimizing the conjunction of once-irradiated debris by leveraging its unique geometry and relative phasing of configurations to revisit the same debris at different times, distances, and angles. Furthermore, the proposed research efforts intend to apply recent advancements in satellite constellation reconfiguration methods to enable rapid response to high-priority conjunction events. The proposal aims to develop a suite of mathematical models and algorithms critical to enabling a reconfigurable space-based laser network.
Status: Active
Description: <p>This project will develop a Deep Contact Graph Routing (Deep CGR) algorithm using real space systems provided by Astrobotic. Deep CGR uses Deep Learning methods to generalize and enhance Contact Graph Routing methods used in Disruption Tolerant Networks (DTNs). Deep Neural Networks (DNNs) will be used to predict radio channel quality (Channel State Information, CSI) as a function of robot position and time, and a joint communication / robot motion planner will be developed. We expect the planner to generate emergent strategies that combine planning over robot pose and communication system state. Hardware-in-the-loop (HIL) tests will be performed in a relevant environment (a quarry on earth) to demonstrate the feasibility of the proposed solution.</p>
Status: Completed
Description: <p>Refractory alloys, including tungsten and its alloys, have high strength at elevated temperatures, good wear resistance, high thermal/electrical conductivity, low coefficient of thermal expansion and excellent creep resistance, which makes them especially suitable for a number of NASA-relevant applications, such as leading edges and thermal management systems. . Unfortunately, these alloys tend to be brittle and are challenging to fabricate into complex shapes. Recently, Additive Manufacturing (AM) has emerged as a potential game-changing approach to fabricate near-net shape components from many advanced materials Unfortunately, existing refractory alloys are not necessarily 'printable' and AM protocols used to print other alloy classes are not transferable to the refractory alloy space. In this work, we propose to address this double challenge by putting forward a framework to identify new composition and processing windows that surpass the current performance of existing refractory alloys, while ensuring their printability. We will combine novel computational alloy design frameworks with novel alloy prototyping technologies to identify alloy compositions suitable for high temperature applications that are at the same time suitable feedstock for AM. We will use advanced statistical methods and experiments to map the regions in the process space leading to defect-free deposition. The proposed alloy+process design framework will be validated through experimental characterization, followed by the fabrication of components of complex geometries relevant to aerospace applications.</p>
Status: Completed
Description: <p>In the coming years, we look towards the stars and aim toward becoming a multi-planetary species. The return to the moon hasalways been forthcoming since our last encounter in 1969, and with the recent discovery of water on the sunlit side of the moonby NASA’s SOFIA, this mission becomes ever critical. We also look farther into the solar system at similar bodies such as Marsand Jupiter's moons. However, the journey to these bodies and setting up a habitable colony will not be easy. The terrains in theseinterplanetary entities will be vastly different than Earth’s terrain and will feature craters, ice, and even mountainous grounds.Moreover, these habitable entities typically have lower gravity than on Earth. The two features will make locomotion by humansand their assistive robots particularly difficult. Firstly, the low gravity makes for less traction and the uneven terrain would becumbersome to wheeled robots. As such, we envision that legged robots, more so quadrupeds, will be at the astronaut’s side to help setup habitable colonies on other worlds.Robots that will aid the exploration of interplanetary environments will require fast and fluid motions and must be able to transverseterrains that vary from sand to ice or even mountainous grounds. To achieve this feat, robotics control solutions, e.g., optimal control(OC) methods, will need to be a) faster than real time and b) aware and responsive to the low gravity problem.In this research proposal, we aim to answer these challenges via a set of four objectives. 1) Firstly, we will develop control strategiesfor quadrupeds to navigate complex and varied terrains. Here, we will use a tool named Differential Dynamic Programming (DDP)that can produce OC solutions in real time. This tool is extremely powerful and features a correction term that enables maintainingstability without re-optimizing for quadrupeds in different terrains. Here, we note that DDP relies on an initial trajectory in itsoptimization. The choice of this initial trajectory is critical to the computation speed of DDP.This observation brings about our second objective. 2) This research will pursue the development of a learning library of gaits,footholds, terrains, and their correspondent OC. Once developed, when the quadruped encounters a terrain in the other world, itwill query the library for a trajectory. It will use the queried trajectory as the initial guess. This will allow for faster than real-timecomputation of optimal gaits in different terrains. Moreover, this learning library will be made to be dynamic so that it grows overtime (within limits) to add new terrain information. These two objectives deal with the first problem of computing control laws fasterthan real time, but we also need to deal with the problem of low gravity.To deal with this problem of low gravity, we introduce the third objective. 3) This research objective will consider the addition of anextra appendage (flywheel or control moment gyroscope) to the quadruped. This extra appendage will generate the requisite bodytorque to counteract the reduced traction and thus will help to maintain stability in low-gravity environments. The control problemis now seen through the lens of handling the conservation of angular momentum. This advance will lead to a quadruped that is moreresponsive in low-gravity environments and even in the presence of external disturbances.Finally, the last objective will (4) validate and unify all the previous objectives in simulations and hardware experiments. We willfocus on quadruped robots like the University of Notre Dame’s MIT mini-cheetah and potentially other mobile platforms such as theNASA Jet Propulsion Laboratory's (JPL) LLAMA and LEMUR multilegged robots. The visiting technologist role will serve as anopportunity to inject relevant data into the project, carry out experiments with new systems, and work on the outlined objectives.</p>
Status: Completed
Description: <p>The current state-of-the-art planetary rover technology, such as Mars 2020 and Curiosity, are limited in their ability to both access extreme terrain and create high-force environmental interaction. To overcome these limitations, we will develop a team of small, agile jumping, and self-anchoring robots will both be able to move over obstacles and through challenging terrain as well as apply significant forces to the environment. The small robots will be capable of jumping unprecedented heights and distances, enabling them to access extreme terrain. Further, each will be capable of “growing” root-like structures into the soil such that each will be able to create reaction forces one or more orders of magnitude larger than its weight, and when working in a coordinated team, will be able to perform high-force environmental interaction. The proposed concept will lead to substantial system-level advantages. The robot team will be: (i) small, light and inexpensive, due to anchoring and load-sharing to generate reaction forces even in low gravity environments; (ii) operationally simple, due to simple robot design; and (iii) redundant with increased system reliability due to multiple robot team members.</p>
Status: Completed
Description: <p>The primary outcome of this project includes a fully integrated structural-thermal-optical (STOP) analysis of a space-based precision-pointed telescope design, such as WFIRST. The STOP analysis will provide rigorous uncertainty quantification and sensitivity analysis for the system. This work will address the need for uncertainty propagation throughout the spacecraft modeling process. The current process is to model each subsystem and add an estimated uncertainty downstream of the model’s worst-case outputs. While this is usually sufficient to cover all potential mission scenarios, it also leads to overly conservative designs. Additionally, it is very difficult to pinpoint specific portions of the spacecraft that must be tested more thoroughly during the verification and validation process.<br /> <br /> Working to create a Bayesian-based model validation (BMV) system for this STOP analysis will help to not only reduce the time it takes for model validation, but it can also provide engineers with more information about the system earlier in the design process. By providing uncertainty propagation throughout the models, engineers can pinpoint at any stage of the design process which design parameters have the most uncertainty in value. Monte Carlo methods will be used to perform this uncertainty quantification, and techniques such as two-stage Markov Chain Monte Carlo and the control variate framework will be used to reduce the computational cost of propagating uncertainty. This can be further analyzed with a distributional sensitivity analysis, which will identify the model parameters with the most variance. Laboratory tests can then be designed to provide more information about those specific parameters. A multi-fidelity model will be implemented to help reduce the computation time for the distributional sensitivity analysis (DSA), as the DSA can be iterated in a low-fidelity model if that model can estimate the system response with a similar accuracy to the high-fidelity models. With the proposed methodology of uncertainty and sensitivity analysis for the integrated multi-fidelity structural-thermal-optical model, more can be learned about the system, even in early stages of design, and this model validation can help to determine the system response in scenarios that cannot be easily tested on the ground for large, space-based telescopes.</p>
Status: Completed
Description: <p>Tungsten (W) is key for innovative integrative thermal management systems that are capable of operating at extreme temperatures. Some disruptive NASA high-temperature applications include W as a matrix material for nuclear thermal propulsion (NTP) fuel elements, as a shielding material for solar probes, and as a containment material for advanced heat-pipe cooled wing leading-edge designs. Because W-based materials are refractory materials, melting and casting of these materials is extremely difficult. The project objective aims to demonstrate an advanced additive manufacturing (AM) method to improve the properties of high temperature tungsten (W) and W-alloys as high-temperature materials. Targeted properties of interest are to improve the grain structure while minimizing the porosity and micro-cracking of fabricated components. This will be achieved by robocasting (direct ink writing) of colloidal gels containing W and W-alloys to fabricate “green bodies” in cylindrical and “dog bone” shapes that will then be densified by flash sintering. Atomic layer deposition (Particle ALD) will be used to add dopants and sintering aids, and then the coated powders will be processed into colloidal gels for robocasting. The result from this work is anticipated to be transformational if it is demonstrated that near full density of W and W-alloys can be achieved with minimal grain growth using flash sintering of robocasted “green” parts fabricated using Particle ALD doped W particles.</p>
Status: Completed
Description: <p>Novel analytical methods that can be deployed in space for the identification and measurement of organic molecules that are representative of biotic samples are essential for confirming the existence of extraterrestrial life. Capillary electrophoresis (CE) coupled to electrospray ionization mass spectrometry (MS) is a powerful analytical tool that can be used to separate and identify organic molecules that are biosignatures of life and has the potential to be integrated into a space mission. Sample acquisition and preparation are critically important steps for successful implementation of CE-MS for biosignature detection. To obtain the maximum chemical information, it is crucial that any cells found in extraterrestrial samples are lysed and the maximum yield of organic molecules is achieved. The molecules detected by CE-MS can then be used as a fingerprint of the types of cells that are present. This proposal concerns the development of a modular device to trap and lyse cells and concentrate organic molecules that can be integrated directly with CE-MS. This system will be evaluated using complex brine water samples similar to what would be expected on Europa. An important goal is to identify specific molecules that can be used as biosignatures for particular cell types using bacteria as a model organism. This integrated approach will improve the detection limits for cells and their components and enable profiling/identification of any cellular life found on an ocean world. This technology meets the goal of NASA TA 8.3.3.6, “Wet Chemistry Technologies for Life Detection.”</p>
Status: Completed
Description: <p>The goal of this research is to develop accurate and efficient models covering the scales from microscopic charging (micrometermicrosecondscale) to macroscopic transport (meter-second scale) of dust grains through computational and data-enabled modelingstudies. This project will bridge the gap between microscopic charging and macroscopic transport of dust grains for interactions inspace. Particularly, this project will self-consistently resolve the net amount of charge (Qd) on each individual dust grain for differentconfigurations at multiple scales. Also, this project is the first to apply data-driven modeling and uncertainty quantification to firstprinciple-based particle simulations of complex/dusty plasmas. Computationally efficient and accurate models will be developedfor multi-scale interactions. Effects of uncertainty sources, such as plasma environment, dust size, and physical properties, in thosemodels will be quantified and analyzed. The outcome this project is an efficient and accurate model of lunar plasma-dust environmentthat can be used as a rapid analysis tool to predict quantities of interest for Artemis missions, such as local electrostatic and dustenvironment (e.g., surface potentials, levitated dust size and height distribution), risks of electric discharging/arcing, efficacy of dustmitigation schemes for surface operation and habitat, etc.</p>
Status: Completed
Description: In nature, there exists a class of materials which are inherently two-dimensional (2D). Although they form solid 3D structures, the individual atoms have strong bonds in one plane, and weak bonds out of plane; a single sheet can be separated from the bulk. These are called van der Waals (VDW) materials. 2D and VDW materials will be extremely useful to NASA in many electronic and optical devices due to their low weight and high efficiency. Throughout this proposal, I will discuss the unique properties of 2D and VDW materials, and the opportunities to combine multiple 2D materials into a hybrid metamaterial. A multi-functional solid state device can be constructed by the stacking of different-function 2D layers. The 2D layers can participate in conduction, insulation, light-matter interactions, ion storage, catalysis, charge storage, and coupling. The questions that need to be answered are: (i) how does hybridization alter the properties of the layer; (ii) can we form hybrids with layers which behave independently; (iii) and do unique properties exist in hybrids which do not manifest in homogeneous VDW materials? To answer these questions requires probing hybrids with differing composition and geometry. Synthesis of a wide range of hybrid VDW materials is not possible without being overly expensive and time consuming. But, manufacturing a specific material cheaply and efficiently is certainly possible. Additionally, the computational and theoretical techniques we will use are widely applicable; we can calculate a hybrid's electronic and optical properties and easily switch to study a hybrid with significantly different elemental makeup and hybridization. I will perform analytical calculations, modeling, and Density Functional Theory (DFT) studies to answer the above questions, and I will use our results to motivate the synthesis of new materials for devices that are of interest to NASA.
Status: Completed
Description: <p>I am conducting novel research on the use of dual quaternions for the modeling and control of spacecraft used for gravity recovery missions such as the GRACE and GRACE-FO NASA missions. Measuring Earth's temporal and spatially varying gravity field is of significant interest to many fields of study, including ocean dynamics, sea-level rise, post-glacial rebound, etc. The novelty of this research is that although the dual quaternion modeling approach has shown significant promise in past research for efficiently and accurately modeling the coupled relative dynamics of spacecraft, this approach has never been employed for gravity recovery missions. Gravity recovery missions make ideal candidates for proving the merit of dual quaternions because very precise measurements must be taken between formation flying spacecraft and taken between the spacecraft and their test masses. The assumptions needed to implement traditional modeling and control methods on gravity recovery missions increase error in these measurements. Therefore, it is expected that this work will be transformational for gravity recovery missions since dual quaternions are not limited by the assumptions of traditional methods, which gives dual quaternions the potential to improve calculations used to map Earth’s gravitational field. For this research, a dual quaternion modeling approach is compared to traditional modeling methods for modeling the 12 degree-of-freedom coupled relative dynamics of a spacecraft and its test mass. The two modeling approaches will be compared to existing GRACE-FO data products to compare the accuracy and utility of both methods. Controllers designed from the dual quaternion approach will also be explored and compared against the typical control approaches currently utilized on gravity recovery missions. I expect that the dual quaternion control and modeling approach will show an increase in performance and/or accuracy over traditional methods, and therefore prove the dual quaternion’s transformational potential for gravity recovery missions.</p>
Status: Completed
Description: <p>Hollow cathodes are a vital component for the ignition and plume neutralization of Hall effect thrusters (HETs). Traditional HETs are known to exhibit significant erosion along the channel walls of the thruster through ion bombardment. Magnetically shielded HETs have nearly eliminated this short term erosion mechanism; however, a new long term azimuthal erosion pattern has been measured on the inner front pole cover. Literature has suggested that ions stemming from both the cathode and the beam through charge exchange collisions are the cause for this new erosion pattern. However, the physical mechanism for this erosion and growth of ions from the cathode is unclear. The proposed research will investigate the high energy ions generated specifically at the cathode through observing the turbulence in a partially magnetized hollow cathode plume. In lone cathode experiments without an applied magnetic field, the cathode is known to operate under a quiescent "spot" mode and an oscillatory "plume" mode. Plume mode has shown to increase the keeper erosion of cathodes. It has been suggested that the predator prey oscillations in the plume coupled with ohmic heating due to ion acoustic turbulence (IAT) is the cause for the spot to plume mode transition. However, when electrons are magnetized, as they are in HET plumes, the cathode appears to operate in an entirely different mode, deviating from the traditional spot or plume mode. Further, with the application of the external magnetic field, azimuthally travelling high energy ions appear. The proposed research will investigate IAT and the azimuthally drifting ions with a high speed ion saturation probe array for a wave dispersion analysis (WDP), a high speed Langmuir probe (HSLP), and a high speed retarding potential analyzer (HSRPA). The dispersion analysis will be performed using a method defined by Beall for two ion saturation probes. Reconstructive Fourier transfer techniques will be used to resolve the spatial turbulent plasma parameters collected at the probes. An understanding of the turbulent plasma waves in hollow cathodes will provide insight in long-term erosion patterns observed in HETs. Further analysis with full thruster operation will show how the thruster environment affects the measured turbulence. The knowledge gained from this research will greatly contribute to the understanding of HET life-limiting factors.</p>
Status: Active
Description: <p>In-situ Resource Utilization (ISRU) technologies are critical for enabling long-duration crewed missions. Reducing or even eliminatingEarth-launched supplies greatly reduces launch costs and advances operational flexibility via more robust resource utilizationcapabilities. In lunar in-situ fuel, oxygen, and water production, volatiles must be captured and separated both in the initial capturephase and throughout subsequent processing and refining. In its 2015 Technology Roadmap, NASA specifically called for research inmembrane-facilitated gas separations for these applications. This project aims to investigate the feasibility of supported ionic liquidmembranes (SILMs) for gas separations in lunar ISRU.SILMs consist of a porous membrane filled with an ionic liquid (IL) sorbent. ILs have shown promise in a variety of gas separationsand are more stable under low pressures and high temperatures than other liquids. SILMs have also been studied in carbon dioxideand humidity removal but remain at low TRL. The first objective of this investigation is initial ionic liquid identification andcharacterization, informed by literature review and screening for favorable characteristics which vary depending on the target gas.The second objective, membrane identification and SILM production, will be accomplished through screening of membranes andverified through chemical analysis. The third objective will be to conduct individual SILM performance testing, performed at varioustemperatures and pressures for a variety of mixed gas feed compositions. This will yield values for permeance of each membrane andwill verify their stability. The final objective is to assess the feasibility of a multi-stage SILM separation system for lunar ISRU gasseparations. Here, data from the third objective will enable chemical process modeling, and construction and testing of a small-scalemulti-stage system will verify the model’s feasibility assessment.This study addresses NASA’s need for membrane separation technology for lunar gas separations. Successful application of SILM gasseparations will bolster human spaceflight capability.</p>
Status: Active
Description: Within the last decade, the space industry has steadily increased its usage of electric propulsion (EP), viewing it as a solution to many longevity and fuel consumption issues raised by the inherent weight limits for chemical propulsion rockets. Given the high specific impulse of EP thrusters, improving our knowledge of its efficiency and functionality, particularly as it relates to EP-generated plasma behavior, is imperative for long-term human exploration and expansion into deep space. Computational models especially are key to developing an enhanced understanding of the plasma behavior within the thrusters, as experimental facilities cannot fully emulate conditions found during flight, and data gathered may be negatively impacted by facility effects. In fact, when it comes to the space environment, it is exceedingly difficult to predict plasma and space weather behavior experimentally, and thus much of the current spacecraft design is based upon computational models of the plasma environment. Despite the abundance of models that predict plasma behavior within EP devices and the space environment, there have been fewer studies that have targeted simulating the coupling between the space plasma environment, the plasma emitted by EP devices, and the spacecraft. Previous studies have modeled space plasma effects on EP systems, but have primarily focused on nanosatellites with simple spacecraft geometries, and often neglect phenomena such as secondary electron emissions and the photoelectric effect, which can fundamentally change space plasma behavior. In order to address these research gaps, this project proposes increasing the predictability of current spacecraft charging models by focusing on three main aspects. The first is the development of a high- fidelity spacecraft charging model that utilizes kinetic theory to couple EP-generated plasmas with ambient space environment plasma simulations. The result will likely be a 3D Particle-in-cell (PIC) code. The second is the utilization of this model on complicated, realistic spacecraft geometries. The final topic is scaling the resulting computational model to simulate larger and higher power spacecraft systems. Altogether, we propose leveraging existing computational software that model various EP device behavior to develop our own robust Hall Thruster Kinetic model and augmenting it with space environment simulations in order to develop a more thorough understanding of the effect the two plasma populations have on each other when the EP device is in use. The final product will prove very impactful to the space and defense industry. Spacecraft charging has the potential to compromise the function of sensitive electronics and solar arrays which power EP devices, as well as cause material degradation, signal failure, power fluctuations, and noise. In addition, the discovery of any potentially negative effects on thruster performance and efficiency, material degradation, and the necessity of ion beam neutralizers will be essential to the future planning and deployment of further near-earth and deep-space EP missions. In fact, this study may open up new opportunities for space exploration via new orbit paths and missions which would encourage novel scientific pursuits.
Status: Active
Description: <p>The goal of this proposal is to develop a real-time perception-aware trajectory planner for autonomous planetary landing missions. The autonomous lander must be able to safely land in unseen and treacherous environments by reasoning about uncertainty in perception information and swiftly adapting its desired landing location based on new observations. The three key research thrusts are: (1) Developing a systematic approach to tightly integrate perception with trajectory planning to actively monitor potential landing sites and replan to a new landing site if the current site is deemed unviable as new observations are received. (2) Constructing a principled approach to prioritizing landing sites that balance safety considerations with proximity to scientific points of interest(s). (3) Designing operationally relevant tests to validate the effectiveness of the proposed perception-aware planning algorithm and demonstrate its real-time capabilities on various hardware platforms. This research directly benefits NASA's Entry, Descent, and Landing (EDL) research interests, with a particular focus on Robot Navigation (TA4.2.6) for autonomous planetary landings especially in cases where there is little to no a priori information about the environment. Additionally, this research addresses the challenges of Large Divert Guidance (TA9.2.6), Autonomous Targeting (TA9.2.8), and Guidance, Navigation, and Control for EDL (TA9.2.6) as core elements of the research include identifying and monitoring potential landing sights, and planning feasible trajectories that can reach multiple potential landing sites in case some are deemed infeasible later on.</p>
Status: Active
Description: <p>When robots are sent to the surface of Mars or space stations like the ISS or Gateway, they will need to act autonomously for long durations of time and be exposed to challenging environments. In these conditions, robots have a high likelihood of experiencing some form of system failure. Presently, most robotic missions require engineers to develop pre-designed failure responses, significantly increasing the preparation time and decreasing the robot’s ability to continue operating if it fails in an unforeseen way. This current approach does not offer the scalability needed for large-scale robot deployments to happen--deployments that NASA will need to pave the way for humans to go back to the Moon and eventually Mars. To enable mass robotic systems to accompany and lead long-term space missions, my research will develop a unified system that utilizes redundant actuation to creatively adapt a robot’s actions in real-time in the event of one or multiple faults. Autonomous robots using this system will have greater flexibility than with classic control loops alone. This will increase the time between catastrophic failures, decrease the cost of robot deployment, and improve mission longevity. This research will present a controller-based Fault Detection, Isolation, and Recovery (CFDIR) method to adapt control systems to novel major fault types using null space manifolds. It will then utilize reinforcement learning(RL) to analyze variations in the control system due to prolonged wear and tear and adapt the control parameters to the robot’s condition. CFDIR and RL will be combined to create a task completion probability analysis system(TCAP) that will analyze tasks in a task queue and balance the task’s priority with the probability of completion. This TCAP system will present the factors decreasing the likelihood of completion and suggest ways humans or other robots can assist and increase the probability of completing the task.</p>
Status: Active
Description: <p>In-space manufacturing and assembly are vital to NASA's long-term exploration goals, especially for the Moon and Mars missions. Deploying welding technology in space enables the assembly and repair of structures, reducing logistical burdens and supply needs from Earth. The unique challenges and extreme conditions of space--high thermal variations, microgravity, and vacuum--require advanced welding techniques and computational tools to ensure reliability, repeatability, safety, and structural integrity in one-shot weld scenarios. For the first time, this project investigates these challenges by focusing on three key factors: (1) Very low temperatures in space degrade the weldability of high thermal conductivity materials, like aluminum alloys, making it harder to achieve strong, defect-free welds. (2) The extreme vacuum in space lowers the boiling points of alloying elements, altering the keyhole geometry during welding. This selective vaporization changes the weld’s final chemical composition, affecting its microstructure and properties. (3) Microgravity nearly eliminates buoyancy-driven flow of liquid metal inside the molten pool, preventing gas bubbles from escaping, which leads to porosity and defects in the welds. By examining these critical factors using multi-scale multi-physics models integrated with physics-informed machine learning, and forward/inverse uncertainty quantification techniques, this project provides the first-ever real-time digital twin platform to evaluate welding processes under extreme space/lunar conditions. The models are validated through Earth-based experiments, parabolic flight tests, and publicly available data from different databases and agencies worldwide. Moreover, the established models will facilitate extendibility to support in-situ resource utilization on the Moon, including construction and repair using locally sourced materials like regolith. The established fundamental scientific knowledge will minimize trial-and-error, enable high-quality one-shot welds in space, and reduce the need for reworks, significantly reducing the costs and time needed for space missions.</p>
Status: Completed
Description: <p>Soft robots address key issues that exist with traditional rigid robots -- safety compliances, morphing capabilities, and adaptive behavior among others. However, soft robots are predominately driven by fluidic soft actuators that require tethering to an external reservoir, restricting mobility of these soft robotic systems. To address the mobility issues of frequently used soft actuators, I will synthesize an electro-responsive scalable soft actuator and test this actuator under extreme environments to ensure its versatility. Utilizing the volumetric expansion that arises from the liquid-to-gas phase change, I have synthesized multi-core shell soft microcapsule actuators with solvent cores within a hyper elastic polymeric shell. These thermo-responsive soft microcapsule actuators, synthesized using a scalable double emulsion process, range from diameters of 50 microns up to 3000 microns. When alone, these microcapsule actuators act as microscopic soft actuators, and when a large amount of the microcapsule actuators are embedded within an uncured polymeric matrix, the mixture can be 3D printed and molded into larger macroscopic soft actuators. However, the solvent inclusions typically evacuate the microcapsule actuator after one actuation sequence, preventing cyclic actuation. To increase the technology readiness of this soft microcapsule actuator, I will implement a gas-impermeable layer onto the microcapsule actuators, based off of 2D nanosheet materials, to prevent solvent escape during actuation. From thereon, I will synthesize a Joule heating elastic material to act as the carrier matrix of these microcapsule actuators, enabling electro-responsivity in the soft macroscale actuators. Finally, I will test this soft composite actuator under a variety of extreme environments, controlling the temperature and humidity, to determine the environmental effects on this novel soft actuator and synthesize insulating materials accordingly to prevent environmental interference. By enhancing this novel actuator to have cyclic and electro-responsive abilities, along with testing the effects of extreme environments, I will put forth a novel, scalable electro-responsive soft actuator which will untether soft robots. This development will largely benefit the fields of biomedical engineering, extraterrestrial research and discovery, and wearable technologies, where soft robotic systems are essential, but largely immobile.</p>
Status: Active
Description: <p>The use of textile devices for spacecraft structures and decelerator (parachute) systems provides significant stowed versus deployed volume and mass advantages. To assist in the design of these devices, engineers make extensive use of fluid-structure interaction (FSI) modeling. The objective of this project is to advance the state-of-the-art for the FSI simulations of decelerator systems by providing calibrated structural models of the parachute components (canopy fabric, suspension-line cords) in application-relevant conditions (inflation and descent). This advancement will be accomplished though (1) an experimental program that will develop the rules and tools for characterization of canopy fabrics and suspension lines and build a material database for their response in service conditions, (2) the implementation of high-fidelity textile models into NASA-relevant FSI codes, and (3) the validation of the structural models in quasi-static as well as deployment conditions. The innovative aspects of this effort include the development of robust structural models of parachute canopy fabrics and suspension lines, that are not presently available or properly modeled/calibrated, and the creation of the associated test methods and facilities for the characterization of the fabric and line textile material systems for application-relevant conditions. The success of this project, through improved high fidelity FSI modeling, will reduce the cost in time and dollars to build and test multiple prototypes before concluding a final design. In the long term, the results of this research program will facilitate sustainability, affordability, and safety of space science and travel by enabling the design of lightweight reusable decelerator systems, which in turn will reduce the effective weight of the space structures, thereby accommodating either reduced propulsion demands or increasing payload capacity. </p>
Status: Active
Description: <p>Project Moonbeam will develop a directed energy (DE) system capable of flexible power distribution for difficult-to-reach and mobile applications on the Moon. The modular directed energy system enables a wide variety of lunar mission profiles due its scalability and efficiency, made possible by the Moore’s Law-like exponential growth in photonics. The project goal is to create a “photonic extension cord,” beaming near-infrared directed energy laser light to distant assets, where it is converted into useful electricity by tuned high efficiency photovoltaics (PV). This technology ultimately enables electrification beyond 1km, such as tower-to-tower power beaming with distances exceeding 100km and power levels exceeding 10kW. The overall effort consists of: (1) the development of a high-efficiency low mass laser and laser PV converter, including thermal management/storage, (2) the design and construction of a high-fidelity laboratory demonstration system, including a 4π beam director and a fine pointing system for target locking, capable of field use and extendable to flight, and (3) a full >100We test.</p>
Status: Completed
Description: <p>During atmospheric entry, a hypersonic space vehicle is often slowed down by drag forces, which convert kinetic energy into heat. Thermal protection systems (TPS) help to keep this heat from harming the vehicle. These TPS are often made of an ablative material, which has a base made of a carbon fiber matrix. The process of ablation helps absorb the heat through mass removal of the material. However, the fibers that make up the carbon matrix are extremely thin, making them brittle. The process of spallation occurs when pieces of these fibers break from the matrix, resulting in many unwanted effects. Although understanding this process is important to accurately designing and analyzing the TPS, it is currently modeled using only an empirical parameter. However, results from recent arc-jet experiments provide an analyzed data set that gives further insight into this process—what causes it, the frequency of particles produced, and the resulting distribution of particle size. Additionally, utilizing the coupled computational fluid dynamics and material response solver known as KATS, the Gas Surface Interactions Lab is working to model individual spalled particles and their effects on the TPS. This code couples with the KATS solution to determine the chemical reactions of the particles with the surrounding flow field and the effects of individual particles on heating rates. However, it does not take into account how often or at what volume these particles are produced, or the material response to this particle production. Thus, this research seeks to develop the experimental results into a model that can be implemented into KATS to imitate spallation effects on the TPS. This model will allow the TPS to produce particles at a rate and size distribution relative to the given flow and sample conditions, as well as implement the resulting mass loss on the material.</p>
Status: Completed
Description: <p>In recent years, the idea of using rotating detonation engines (RDE) for space propulsion has garnered much attention. RDEs are atype of pressure-grain combustion whereas traditional are operated with constant pressure combustion. There is a greater amountof thermodynamic work that can be extracted from a pressure-gain system. Therefore, RDEs operate at a higher efficiency thantraditional systems. Extensive work has already been performed for gaseous-fed RDEs. However, liquid propellant fed systems stillrequire extensive experimental testing and analysis. There is a need to develop a highly resolved spatial and temporal diagnostic tostudy the liquid-shock interaction, vaporization, and combustion in RDEs. Research in this area satisfies the goals laid out in theTechnology Roadmap, section TA 1.2.4.Accurate knowledge of the evolution of a liquid propellant spray in a detonation environment is instrumental in developing liquid fedRDEs. This proposal seeks to measure the liquid-shock interaction of traditional liquid rocket propellants via MHz rate imaging andburst-mode lasers. Laser-based measurements have a massive advantage over traditional techniques because lasers are non-intrusiveto the flow field. The primary development in this work will be with 2-D Stokes-Raman scattering. This is similar to the prevalentand well-known Rayleigh scattering effect. However, Raman scattering is an inelastic phenomenon so there is a color shift in theresulting scattered light. The size of the shift differs depending on which molecule is being studied and can be subsequently isolated.High fidelity imaging of liquid oxygen, liquid methane, and RP-1 in detonation driven flow fields will be made during this study. Thisresearch is instrumental towards the development of functional liquid-fed RDEs for liquid rocket engine applications.</p>
Status: Completed
Description: <p>In the next decade, NASA is prioritizing returning humans safely to the Moon, deploying scientific instruments, and ultimately human exploration of Mars. However, one of the most significant obstacles to achieving this objective is our limited understanding of the interaction between the rocket exhaust and the lunar surface leading to crater evolution and lunar dust formation during descent and touch-down. Some basic scientific issues that remain include crater and particle-plume formation and evolution in non-intrusive, full-domain experiments; scaling laws to correlate data and predict planetary landing conditions; and the effects of altitude and descent rate on the aforementioned issues. This investigation, conducted by a multi-disciplinary team including experts in propulsion, fluid mechanics, optical diagnostics, and planetary science, centers on improving our scientific understanding of 3D crater evolution process and particle-jet interactions under sub-atmospheric conditions using a multi-pronged non-intrusive diagnostic approach to achieve the following objectives (1) mature and apply time-resolved, non-intrusive, 2D/3D diagnostic techniques for use in sub-scale and full-scale studies and obtain data suitable for validating current computational models under development, (2) develop scaling laws to permit correlating experimental data to flight conditions for proposed landing sites, and (3) quantify the effects of descent rate on the process and mechanisms of rocket exhaust and lunar surface interactions.</p>
Status: Active
Description: <p>Lunar dust may seem unimposing, but it presents a significant challenge for space missions. Its abrasive and jagged particles can damage equipment, clog devices, and even pose health risks to astronauts. This project addresses such issues by developing advanced coatings composed of crumpled nano-balls made from atomically thin 2D materials such as MoS₂, graphene, and MXenes. By crumpling these nanosheets—much like crumpling a piece of paper—we create compression and aggregation resistant particles that can be dispersed in sprayable solutions. As a thin film coating, these crumpled nano-balls form corrugated structures that passively reduce dust adhesion and surface wear. The deformable crumpled nano-ball (DCN) coating works by minimizing the contact area between lunar dust and surfaces, thanks to its unique nano-engineered design. The 2D materials exhibit exceptional durability, withstanding extreme thermal and vacuum environments, as well as resisting radiation damage. Additionally, the flexoelectric and electrostatically dissipative properties of MoS₂, graphene, and MXenes allow the coating to neutralize and dissipate electrical charges, making them highly responsive to the charged lunar dust environment. The project will be executed in three phases, each designed to bring the technology closer to real-world space applications. First, we will synthesize the crumpled nano-balls and investigate their adhesion properties using advanced microscopy techniques. The second phase will focus on fundamental testing in simulated lunar environments, where the coating will be exposed to extreme temperatures, vacuum, radiation, and abrasion. Finally, the third phase will involve applying the coating to space-heritage materials and conducting comprehensive testing in a simulated lunar environment, targeting up to 90% dust clearance and verifying durability over repeated cycles of dust exposure. This research aligns with NASA’s goals for safer, more sustainable lunar missions by reducing maintenance requirements and extending equipment lifespan. Moreover, the potential applications extend beyond space exploration, with the technology offering promising advances in terrestrial industries such as aerospace and electronics by providing ultra-durable, wear-resistant surfaces. Ultimately, the project contributes to advancing materials science and paving the way for NASA’s long-term vision of sustainable space exploration.</p>
Status: Active
Description: <p>Improved rocket propulsion directly translates to reduced fuel requirements and increased payloads for space flight. Rotating detonation rocket engines (RDREs) have the potential to provide significant performance gains in thrust-per-fuel ratio, design trade space, and mass savings compared to traditional rocket engines, and are attractive candidates for NASA lander, launch, and attitude-control applications. However, it is not currently known how to optimally design an RDRE injector, chamber, or nozzle to achieve what theory suggests is possible, so NASA needs capability for improved understanding of RDRE behavior. Because in situ diagnostics are limited and detailed computation is too computationally intensive for design iteration, I propose to develop a reduced-order computational model, capturing the important features of the flow, with emphasis on understanding the associated chaotic dynamics, for which no model currently exists. My model will run fast enough for use in design iteration and will be used to accelerate NASA’s ongoing RDRE development by quickly providing predictions for many design parameters. This improvement in evaluation turn-around time will allow for more detailed exploration of the design parameter space. In particular, I aim for this model to identify the geometric and operating parameters that determine the development of different wave modes in RDREs. Experiments have shown that current RDREs do not consistently exhibit the same wave modes and that different wave modes can produce different engine performance. Inconsistency in engine performance inhibits both practical use and efficient development of the technology, so the results of this work will inform optimal design practices and significantly advance NASA and industry development of RDREs. Thus, this work will enable the designs with the most favorable properties to be more quickly identified and iteratively refined to improve desired performance measures, directly supporting ongoing NASA development of next-generation RDRE design.</p>
Status: Active
Description: Development of autonomous systems for deep space exploration, Rendezvous, Proximity Operations and Docking (RPOD), and On-Orbit Servicing (OOS) have been of growing interest for NASA as shown by the latest decadal survey and the Space Technology Mission Directorate’s (STMD) Strategic Framework [1, 2]. These systems rely heavily on autonomous navigation capabilities centered around Optical Navigation (OPNAV), the use of resolved bodies in imagery for navigation purposes. Unlike traditional navigation techniques, OPNAV has the ability to recover a full pose estimate from a lightweight and cost-effective digital camera, which is a key benefit in deep space travel where communications may be limited. With image processing, pose estimation, and implementation developments, OPNAV has already played a significant role in furthering space exploration through missions such as OSIRIS-REx and Artemis I [3, 4]. The need for autonomous navigation, and therefore OPNAV, will increase as the space exploration focus shifts from Earth-orbiting missions to cislunar and deep space applications due to these inherent communications delays. OPNAV is inextricably linked to the field of Relative Navigation (RelNav), a branch of navigation that determines the spacecraft’s pose relative to another spacecraft, body, or terrain feature. With techniques such as limb-scanning and surface mapping, NASA has already utilized OPNAV and RelNav on prominent missions. Most notably, the Artemis program has used OPNAV to navigate within cislunar space and image the lunar surface [4]. While this technology has been used on past missions, OPNAV and RelNav technology have limitations on image processing and pose estimation optimality that must be explored further. Spacecraft image processing and feature detection is often a difficult task due to harsh illumination conditions, deployment anomalies, and more. Classical and learned detection methods utilize models of a nominally deployed spacecraft to determine features. On a partially illuminated spacecraft, large shadowed regions are hard to predict and typically confuse the feature detection methods. Similarly, features on a spacecraft experiencing deployment anomalies such as incomplete deployment of solar panels or antennas may be unrecognizable. This technology gap has been recognized by the European Space Agency (ESA) through the Satellite Pose Estimation Challenge (SPEC), yet the results indicate that top algorithms in the competition struggled when tested on real space imagery [5]. This challenge, alongside ongoing research, shows promise in deep learning and analytical solutions to pose estimation using feature descriptors, yet the lack of consensus on methodology and performance on real space imagery further highlights the technology gap within both pose estimation and feature detection. Bridging this technology gap is integral for future missions. For instance, future Artemis missions may utilize emerging RelNav technology in conjunction with traditional OPNAV to dock with spacecraft such as Gateway. Beyond Artemis, future components of the Mars Sample Return (MSR) campaign must perform autonomous navigation and RPOD operations around Mars to collect and return Martian samples [6]. MSR’s operations may benefit significantly from evolving OPNAV and RelNav technology. Developing efficient and robust image processing and pose estimation capabilities will not only enable improved navigation and docking operations for upcoming missions like Artemis and MSR, but also bring technology one step closer to truly autonomous systems. As a Ph.D. student at the Georgia Institute of Technology (GT), I’m interested in investigating the intersection of OPNAV and RelNav and its image processing, pose estimation, and implementation in navigation filtering. This topic will not only advance autonomous navigation needed for upcoming NASA missions, but also further NASA’s Strategic Thrusts as shown in the Strategic Framework. Additionally, it will equip me with relevant skills needed for future navigation work at NASA Johnson Space Center as a current Pathways Program Intern and future full-time engineer. Lastly. this investigation will benefit from Dr. John Christian’s (PI) expertise as of OPNAV and RelNav greatly aligns with his research lab, the Space Exploration and Analysis Laboratory (SEAL) at GT.
Status: Completed
Description: <p>Cassiopeia A is a bright, nearby supernova remnant. It is unique in that it is the only known supernova remnant in which Ti-44 has been directly observed, but it is well understood that Ti-44 plays a key role in supernova dynamics. We observe the presence of Ti-44 in Cassiopeia A via hard X-ray spectral lines that arise from nuclear decay processes. The position distribution of Ti-44 was first imaged by the Nuclear Spectroscopic Telescopic Array (NuSTAR) in 2012, but we now seek more fine-grained velocity information about the Ti-44 distribution. This will be critical for furthering our knowledge of the Cassiopeia A supernova dynamics and, more broadly, the formation of heavy elements in our universe. We propose the development of phonon-mediated and superconducting kinetic inductance detector (KID) technology as a means to achieve world-leading resolution in hard X-ray spectroscopy. This nascent technology requires dedicated research and development to reach the expected sub-0.1 keV FWHM resolution, an order of magnitude better than the detectors used in NuSTAR. My contribution to this effort will include designing, fabricating, and testing a KID device that could be loaded into a NuSTAR-like telescope; improving the fundamental limitation on our energy resolution by testing and implementing a quantum-noise-limited cryogenic amplifier into our readout electronics; and optimizing the material makeup of our devices by leveraging the unique physical properties of superconductors. In these ways, I hope to bring clarity to our understanding of Cassiopeia A and other supernova remnants in our never-ending efforts to explore the final frontier.</p>
Status: Completed
Description: <p>In light of the Artemis 2024 mission, and in preparation for crewed missions to Mars, additive manufacturing has gathered momentum for building construction on other celestial bodies due to the potential for reduced material transport costs and high complexity of printed structures. Direct ink write of simulant Martian regolith, suspended in a polymer binder and solidified by UV curing, offers a solution to the challenges encountered by traditional AM methods in outer space, namely low atmospheres and low gravity. Herein, I propose a comprehensive study for formulating regolith simulant-dense DIW inks and optimizing their processing and weatherability at low temperatures. Rheological characterization and 3 Interval Thixotropy Testing will be employed to assess the effects of regolith particles’ nonuniformity on the suspension’s stability during printing. DMA and TGA will be used to study the effects of monomer crosslinking and particle loading on the binder’s ability to retain a low Tg, preventing brittle mechanical failure. Print performance and adhesion failure through thermal cycling will be assessed through SEM and microCT. A 2-level factorial design of experiments will serve to determine the strongest contributing factors in adhesion failure of 3D printed granular matter. Larger concentrations of smaller particles are expected to yield lower phase stability during printing, while monomers resulting in rapid and tight crosslinking will result in a brittle binder prone to failure. Loss of adhesion due to thermal cycling is anticipated to be the result of differences in the coefficient of thermal expansion of the binder and particles. A successful conclusion of this work will demonstrate new application methods for 3D printing of high solids materials, expand the range of possible printing materials to maximize in-situ resource utilization, while also providing knowledge specific challenges for off-Earth construction.</p>
Status: Active
Description: <p>Establishing a permanent base on the moon is a critical step in the exploration of deep space. One significant challenge observed during the Apollo missions was the adhesion of lunar dust, which can build up on vehicle, equipment, and space suit. Highly fine and abrasive, the dust particles can have adverse mechanical, electrical, and health effects. The proposed research aims to develop a new class of hierarchical, heterogenous nanostructured coating that can passively mitigate adhesion of lunar particles. Using scalable nanolithography and surface modification processes, the geometry and material composition of the nanostructured surface will be precisely engineered to mitigate dust adhesion. This goal will be accomplished by: (1) construct multi-physical models to predict the contributions of various particle adhesion mechanisms, (2) develop scalable nanofabrication processes to enable precise control of hierarchical structures, and (3) develop nanoscale single-probe characterization protocols to characterize adhesion forces in relevant space environments. The proposed approach is compatible with roll-to-roll processing and the dust-mitigation coating can be transfer printed on arbitrary metal, ceramic, and polymer surfaces such as space suits, windows, mechanical machinery, solar panels, and sensor systems that are vital for long-term space exploration.</p>
Status: Active
Description: <p>Energy storage devices which can operate at low temperatures (below 0°C) are highly desirable in the field of space exploration. State- of-the-art storage devices fail in this temperature range generally due to anode polarization and Li dendrite formation. Solutions to this problem have ranged from electrolyte additives, novel electrolyte formulas, and self-powered heaters. Though more effective and easily integrated heating devices are necessary, current strategies either sacrifice power density or are overly complicated by the addition of cell components. Biology researchers have developed a novel heating method for polymerase chain reactions, which require fast, accurate heating to facilitate DNA denaturation, annealing, and extension. In this method, polydimethylsiloxane (PDMS) absorbs surface acoustic waves (SAWs), resulting in extreme acoustothermal heating of over 2,000 K/s. However, to our knowledge, this heating technique is not widely used outside of microfluidic devices. This proposal aims to utilize acoustothermal heating in lithium- ion batteries (LIBs) to achieve rapid heating. Existing literature and preliminary data will be presented to show that this method will produce positive results. We hope to collaborate with NASA experts to create a battery heating device which can heat a full cell from -60°C to 0°C in less than 20 seconds without sacrificing more than 10% of the battery’s energy. We expect that integration of this technique into a commercial-grade pouch cell will not sacrifice more than 5% of the original energy density (~250 Wh kg-1)10. Realizing the potential of this technique will advance NASA roadmap goal TA 3.2.1.3.</p>
Status: Active
Description: <p>The development of parachutes for the deceleration of planetary entry systems poses extraordinary challenges related to inflation dynamics, multi-body dynamics and capsule wake/parachute interactions during deployment and descent. Despite the advances in fluid-structure interaction (FSI) modeling, parachute design continues to rely on extensive ground and flight testing. Computational models need to resolve a wide range of scales to capture the dynamic behavior of parachute systems, and predictive tools are not mature enough for design and optimization. Without reproducing flight phenomena in large and costly wind tunnel experiments, well characterized benchmark data in simplified settings can be used to assess the performance of numerical tools and assist model development. Within this project we develop experiments that enable tailored validation of FSI models, while improving our understanding of parachute dynamics. In-situ x-ray micro-tomography and novel image analysis methods are used to resolve the multiscale mechanical response of parachute materials. Sub-scale wind tunnel experiments aided by advanced diagnostics are carried out to characterize coupled fluid and canopy dynamics at a wide range of time and length scales.</p>
Status: Completed
Description: <p>During planetary entry, a strong bow shock ahead of blunt spacecraft generates large heat loads near the vehicle surface. This is mitigated via thermal protection systems (TPS) which comprises a substantial fraction of the total vehicle mass. This fraction is further scaled by uncertainties in experimental measurements and simulations. Thus, obtaining quality validation data on heating is crucial to improving TPS performance, increasing vehicle capability, and reducing overall costs. The transfer of heat loads occur by either convection or radiation. Recent studies have found radiation to be dominant on the aft shell, wherein radiation strengths and uncertainities scale exponentially with velocity. Accurate modeling of the radiative environment requires precise knowledge of rovibronic transitions at the molecular level. Previous studies have pursued significant efforts towards developing appropriate models for such processes. However, the emission diagnostics currently employed are reliant on excitation rates and spectroscopic constants that are not known with a high degree of certainty. In contrast, laser absorption spectroscopy (LAS)allows for a direct measurement of ground state number density which can be related to key thermodynamic properties. Therefore, I propose to develop a laser absorption diagnostic to directly capture physical processes occurring in vehicle wakes on planetary entry. The aim is not to replace currently employed diagnostics, but to supplement emission measurements of excited states with ground state measurements for varying species of interest. These direct measurements will not only capture key thermodynamic properties in the radiative environment, but also reduce the uncertainty propagated into flow models and aerothermodynamic performance analyses. This research ties directly into current NASA activities for shock layer radiation modeling, aerothermal testing, and development of non-intrusive techniques to support entry systems design. The proposed diagnostic will be demonstrated in Stanford facilities for Earth/air reentry, and may then be extended to any gas composition.</p>
Status: Active
Description: <p>A cryocooler’s performance is strongly dependent on its heat exchanger performance, which is directly proportional to its size. In other words, a high-performance cryocooler is feasible but with the penalty of a prohibitively large and bulky heat exchanger. This work aims to study an unexploited fundamental flow phenomenon for the flow of fluids through wavy channels and use this science to design and optimize wavy channels for realizing compact cryogenic heat exchangers. The wavy channels can be embedded in the current or future cryogenic heat exchanger designs and provide a vast scalability and modularity scope. The new flow phenomenon will be studied and optimized using analytical and computational fluid dynamics and heat transfer models. Additive manufacturing will be pursued to build two optimized wavy channels intended for use in cryocoolers operating at 90 K and 20 K, respectively. The wavy channels will be tested in the PI’s laboratory to demonstrate the feasibility and proof of concept. The new flow phenomenon can be used to reduce the size or enhance the performance of thermal management systems and heat exchangers in numerous applications such as spacecraft electronics, satellites, data centers, automobiles, and energy systems.</p>
Status: Active
Description: <p>Internal defects are always formed in laser welding process due to the keyhole instability, molten pool collapse, and rapid solidification. The extreme lunar environment complicates the reliable implementation of welding, thereby enhancing the welding defects formation. The welding defects are critical material barriers preventing the metal components from Moon exploration. Professor Wei Li’s team will establish an integrated computational materials modelling framework to study the process-structure-property linkage of laser welding under the lunar conditions. The research is emphasized on modelling the internal defects (void, lack of fusion) formed in the lunar laser welding by fully considering the reduced gravity, large temperature change, and extreme vacuum on the Moon surface, and predicting the influence of internal defects on the material and mechanical properties of welding joint. </p>
Status: Active
Description: <p>Lunar dust, with its highly abrasive and electrostatic properties, poses serious threats to the longevity and functionality of spacecraft, habitats, and equipment operating on the Moon. This project aims to develop advanced bioinspired surface textures that effectively repel lunar dust, targeting critical surfaces such as habitat exteriors, doors, and windows. By designing and fabricating innovative micro-/nano-hierarchical core-shell textures, we aim to significantly reduce dust adhesion, ultimately enhancing the performance and durability of lunar infrastructure. Using cutting-edge fabrication methods like two-photon lithography and atomic layer deposition, our team will create resilient, dust-repelling textures inspired by natural surfaces. We will also conduct in-situ testing with a scanning electron microscope to analyze individual particle adhesion and triboelectric effects, gaining critical insights into lunar dust behavior on engineered surfaces. These findings will guide the development of durable surfaces for long-lasting, low-maintenance lunar equipment, with broader applications for other dust-prone environments.</p>
Status: Active
Description: <p>Space travel to planets and moons with a sensible atmosphere requires an atmospheric entry vehicle to deliver payloads safely from orbit to the surface. The entry vehicle generally has a blunt forebody to withstand heating during the high-speed entry phase. However, blunt-body vehicles become dynamically unstable once they slow down to supersonic and transonic speeds. The instabilities cause the angle-of-attack to oscillate, gain amplitude in time and diverge to a point where the vehicle tumbles, resulting in a catastrophic event. The physical mechanisms leading to the dynamic stability and its characteristics remain challenging after decades of meticulous work due to massive flow separation, complex wake flow, and unsteady pressure field of dramatically changing flight and flow conditions of the descending and decelerating vehicle. This proposed research aims to develop hybrid physics-data modeling approaches for space exploration. We focus on innovating a holistic physics-guided machine learning framework for characterizing the dynamic stability and performance of reentry vehicle systems. Our framework is, therefore, motivated to provide a trustworthy learning platform with enhanced model fusion, feature engineering, and symbolic regression capabilities. We will explore the feasibility of new learning approaches to elucidate new physical insights in describing vehicle stability and identify how to utilize multimodal resources extracted from experiments and high-fidelity simulations effectively</p>
Status: Active
Description: <p>A novel technique is proposed that integrates a robust process model with a high-speed multiscale analysis tool (NASMAT) for which verification and validation take place under a building block approach using the commercial FEA software suite Abaqus. A novel approach is proposed to First, a visco-elasto-plastic constitutive model will be developed to determine stress evolution as a function of strain rate and temperature. This model will be integrated into a process modeling framework containing an existing curing and fracture model provided by the University of Massachusetts (UML) Integrated Computational Composites (iComp2) research group. The user-written subroutines that make up the process modeling framework can be accommodated by NASMAT due to its “plug-and-play” functionality. Next, multiscale process modeling and PFA will be conducted on a 3D woven textile. An idealized RUC of a 3D woven textile will be created with the commercial Finite Element Analysis (FEA) suite Abaqus and NASMAT. The effect of the processing on inter/intra-tow cracking, stiffness, and strength properties will be studied and compared. A macroscale model of a C-channel will be developed with the tow architecture guided by X-Ray CT scans. Process modeling and progressive failure will be conducted via concurrent modeling with FEA geometry and a synergistic model in NASMAT. Additionally, NASMAT’s API will allow the software to communicate with a third-party macroscale code such as FEA, Higher-Order Theory for Functionally Graded Materials (HOTFGM) or Carrera’s Unified Formulation (CUF). A resin system of interest to NASA will be characterized and implemented in the process modeling framework and validated with existing data provided by NASA. Finally, efforts will be made to mitigate cracking and reduce cure time in 3D woven PMCs through tow architectural topology and cure cycle gradient-based optimizations using open-source Multidisciplinary Analysis and Optimization (OpenMDAO).</p>
Status: Active
Description: <p>This proposal aims to make NASA’s in-space robotic systems adaptable and multifunctional by enabling autonomous, closed-loop shape change in lightweight, compliant systems. I will do this by overcoming a fundamental issue in proprioception for shape-changing systems: current proprioceptive methods measure deformations from an initial model, rather than true global shape. They then fail when the resting or unactuated shape of the robot changes to adapt to a new task. To solve this, I present stretchable shape-sensing skins (S3s): a platform that, when applied to the surface of a shape-changing robot, can accurately sense its shape without reliance on an initial state or mechanical model. To push towards a vision of multifunctional, lightweight, and human-safe robotic systems, enabling and achieving shape change is essential. S3’s stretchable circuit hardware will be made by solving fundamental manufacturing issues that have kept stretchable circuits from widespread use. Shape estimation algorithms will then be developed to accurately and efficiently sense shape in real time. S3s will then be applied to an existing shape- and stiffness-changing, modular robotic platform to develop the algorithms necessary to achieve closed-loop shape change of a compliant robot for the first time. Shape-changing robots that can adapt to tasks would revolutionize many of NASAs current missions. For example, the current functionality of Astrobee would be augmented if the gripper could change shape and stiffness to achieve different tasks. With increased safety due to the arm/gripper’s compliant nature, Astrobees could help humans side-by-side, or act independently to maintain spacecraft. S3s also address NASA’s need to develop a single, lightweight robot platform that can change shape and gait to operate in multiple terrains. This proposal’s goal of estimating shape and achieving closed loop control of shape in robotic systems is an essential next step to enabling NASA’s next-generation fleet of adaptable, human-safe robots.</p>
Status: Active
Description: <p>When landing payloads in extraterrestrial bodies, the rocket plumes used for terminal descent impinge onto the regolith surface leading to a number of hazards that can compromise the mission and safety of orbiting and surface assets. The supersonic plume causes cratering of the granular substrate, lifts regolith particles that obscure the view of onboard cameras and leads to near-wall high-speed jets with supersonic ejecta that can sandblast surrounding objects. Vehicle and mission designs that anticipate these challenges rely on a better understanding of the coupled interactions between the gas, the lifted particles and the granular surface dynamics. The scarcity of detailed experimental data in relevant environments hinders the development and validation of predictive computational models. The present effort is designed to fill that gap by: 1) developing a suite of diagnostics for probing gas, particulate and granular media dynamics, and 2) applying them to a series of well-controlled, and fundamental sub-scale experiments that reproduce the main aerodynamic parameters representative of Mars and Moon landings. Our experiments will reproduce landing jet velocities and low-pressure environments while targeting substrates of controlled characteristics. Measurement techniques will combine laser-induced fluorescence, optical attenuation tomography, high-speed imaging, optical range sensing, and sensors embedded on the bulk granular media. We anticipate providing a comprehensive set of data with associated uncertainty and sensitivity analyses that will help understanding the complex interactions between phases, guide model development, and serve as validation of predictive numerical tools.</p>
Status: Completed
Description: <p>Diffraction-limited spaceborne optical systems require an accurate physical optical model to understand how the instrument performs. The design teams for NASA’s flagship observatories (e.g. JWST, Roman) achieve such a model through an ensemble of commercial ray tracers (Zemax, Code V) and open-source physical optics propagators (POPPY, PROPER). Considerations for polarization, misalignment errors, and the ideal wave optics performance are handled separately. This inhibits the designers of spaceborne systems from optimizing their instruments across all potential optical performance limiters. We propose the development of a new physical optics design tool that considers diffraction, polarization, and misalignment errors simultaneously. This tool utilizes Gaussian Beamlet Decomposition (GBD), a technique of propagating complex optical fields through a linear superposition of Gaussian beams. GBD’s strength lies in the ability to propagate the Gaussian beams using the linear laws of geometrical raytracing, enabling near-field diffraction calculations without computation of diffraction integrals (e.g. Fresnel, Angular Spectrum). The proposed design tool will leverage the geometrical nature of gaussian beamlets to compute the impact of optical system misalignment. Polarization aberrations will be considered by assigning a Jones vector to each Gaussian beam, enabling an expeditious calculation of vector diffraction in an optical system. The code generated from the proposed investigation will be formally integrated into POPPY (Physical Optics Propagation in Python) to enable open-source access through an already established physical optics tool tailored to the design of space telescopes (JWST, Roman). This project will advance the design process of spaceborne optical instrumentation by enabling greater simultaneous knowledge of the actual system performance. We further anticipate that GBD will be able to assist in the development of coronagraphic instruments identified for future investigation in NASA’s Decadal Survey (LUVOIR, HabEX),enhancing the search for exoplanets.</p>
Status: Active
Description: <p>Cryocoolers represent an enabling technology in space applications. Large linear (Stirling and pulse tube) cryocoolers, with cooling capacities of 150 W at 90 K and 20 W at 20 K, are needed for future long-duration space missions for in-situ resource utilization (ISRU) and controlling of boil-off in storage of cryogenic propellants. However, efficiency in present state-of-art large linear coolers is reduced by flow asymmetries in their regenerative heat exchangers (regenerators) – an issue that worsens as the regenerator size increases. In this research, we will develop and demonstrate a computational fluid dynamics (CFD)-assisted and micro-manufacturing-based bottom-up design and fabrication methodology for high-capacity and highly efficient regenerators. The primary causes of loss of efficiency in large regenerators, including jetting, flow non-uniformity, the formation of preferential flow passages and recirculation regions, are avoided by the combination of proper inlet and outlet ducting and strategic adjustment of pore microstructures along the length and width of the regenerator. Detailed CFD analysis will be performed, prototype regenerators will be fabricated, experiments will be performed where the fabricated regenerator(s) are tested, and the scalability of the methodology and designed regenerator(s) will be demonstrated. We expect our results to be readily applicable for design and fabrication of large regenerative cryocoolers.</p>
Status: Active
Description: <p>We propose to develop technologies appropriate to a high-efficiency, multi-stage recuperative cryocooler that can provide tens to hundreds of Watts of refrigeration capacity for application such as the liquefaction and storage of methane (110 K), oxygen (90 K), and hydrogen (20 K). On the larger scale these coolers could be used to liquefy cryogenic fuels and oxidizers that might be generated at a remote site. They could also be used to provide cooling during long-range missions providing cooling for cryogens; and possibly, for superconducting-magnet-based radiation shielding. In addition, these coolers can be further staged to provide significant 4 K cooling to support space telescopes and instruments for infrared astronomy and for instruments using low temperature detectors. </p>
Status: Completed
Description: The goal of this research grant is to develop novel vision-based methods to autonomously estimate a robotic spacecraft’s pose relative to a target small body while simultaneously reconstructing and characterizing the body's surface to reduce reliance on humans-in-the-loop and to provide an autonomous alternative to state-of-the-practice small body shape reconstruction methods. The proposed methodology is comprised of four key ingredients, followed by a rigorous validation plan. First, data-driven methods that leverage deep convolution neural networks (CNNs) will be employed to jointly learn robust keypoint detectors and feature descriptors for improved data association in the front-end of the proposed system. Second, optimal information fusion between different sensor modalities and application-specific constraints will be accomplished via graph-based smoothing in the back-end of the system to concurrently estimate the pose of the spacecraft and a map of the body. Third, photometric stereo techniques will be factored into the proposed system to estimate surface gradients and albedos to provide detailed topological information to aid in 3D reconstruction and characterization of the body. Fourth, efficient graph cut optimization methods and an adaptive space discretization will be employed to construct a mesh of the body using the spatial and topological information. Finally, the proposed approach will be validated using real imagery from past small body missions as well as experimentally tested on the ASTROS platform at Georgia Tech.
Status: Active
Description: <p>The vision of the RETH Institute is to develop and demonstrate transformative smart autonomous habitats and related technologies that will adapt, absorb and rapidly recover from expected and unexpected disruptions to deep space habitat systems without fundamental changes in function or sacrifices in safety. Incorporating a system resilience approach will be the turning point in achieving permanent deep space habitats. Deep space habitats require groundbreaking technological advances to overcome the unprecedented demands introduced by isolation and extreme environments. An Earth-independent permanent extraterrestrial habitat system must function as intended under continuous disruptive conditions that occur during both manned and unmanned conditions. Designing for the demands that extreme environments will place on long-term deep space habitats, such as wild temperature fluctuations, galactic cosmic rays, destructive dust, meteoroid impacts (direct or indirect), vibrations, and solar particle events, represents one of the greatest challenges in this endeavor. This context necessitates that we design and operate deep space habitat systems to be resilient. Yet, resilience is not simply robustness or redundancy. Instead, it is a comprehensive approach that accounts for disruptions through the design process and adapts to them in operation. However, we currently lack the innovative design frameworks and technologies needed for deep space habitats to successfully achieve this level of resilience and function autonomously under (and transition between) a variety of unmanned and manned operating modes. The Resilient ExtraTerrestrial Habitats research institute (RETHi) will harness promising next-generation technological advances to overcome the grand challenge of deep space habitation. By leveraging world-leading expertise in developing civil infrastructure responsive to catastrophic natural hazards and merging it with leaders in the fields of autonomous robotics, hybrid simulation, machine learning, smart buildings, complex systems, and diagnostics and prognostics, we will develop and demonstrate the transformative technologies needed to construct resilient deep space habitats that can adapt, absorb and rapidly recover from expected and unexpected disruptions to deep space habitat systems without fundamental changes in function or sacrifices in safety. The RETH Institute is focused on the effective and efficient design and development of a resilient autonomous SmartHab as a complex system (i.e. characterized by a high degree of technical complexity, social intricacy, and interconnected processes). This institute will focus on several key conditions that challenge the development of resilient autonomous deep space habitat systems. First, since the habitat system is subjected to extreme adversarial and environmental conditions, the occurrence of failure is inevitable. Although the habitat system must continue to operate in degraded (a.k.a. survivability) mode, the emergent behavior of such complex systems cannot be clearly understood by studying its components in isolation. Second, in complex systems, where catastrophe involves cascading and often unforeseen faults and failures, traditional risk assessments based on a failure-centric viewpoint are not sufficient. These systems contain changing mixtures of latent faults and failures. Suppression of all latent failures is limited, primarily due to feasibility constraints (cost, transportation and construction). In addition, the complexity of such interconnected systems makes it difficult to understand how such failures might contribute to system catastrophes. Last but not least, in a SmartHab, human operators and autonomous robotic systems can play dual roles: as producers of, and as defenders against, failures. SmartHabs will need to have appropriate defenses that combat both the hazards, deterioration, and commonplace faults that may occur in all electro-mechanical systems, while specifically incorporating principles of resilience to reduce, capture, model, and control emergent behaviors that complex systems exhibit. RETHi will provide an agile and efficient organizational structure to strategically meet the following tightly-integrated key research objectives: •Establish a control-theoretic resilience framework to support resilient design, operation and management while anticipating an evolving and growing habitat over time; •Conduct the research and development to establish SmartHabs with autonomous abilities to sense, anticipate and respond, under a variety of manned and unmanned configurations; •Develop decision-making techniques that can weigh alternatives for complex interconnected, interdependent habitat systems, while also understanding, and when necessary combating, the natural human instinct to interfere or override automated systems; and •Contribute to NASA’s mission to educate the next generation of engineers and scientists, while building partnerships with US industries and organizations, and other nations, and generate research and data products that will inform and guide future R&D. RETHi will achieve resilience by using a control-theoretic approach that supports smart habitat system architecture (Thrust 1), while developing and exploiting autonomous smart habitat interventions that enable response, repair and recovery (Thrust 3). Smart context-based situational awareness (Thrust 2) will take the form of a health management system that will make decisions that reflect both the importance and complexity of the SmartHab, while also learning and predicting future behaviors, needs, and responses. Throughout RETHi’s research, consideration will be given to the interactions between humans and robots, recognizing their ability to both produce and defend against failures. These parallel but interconnected efforts will converge in the establishment of a cyber-physical testbed that integrates strategically-selected physical models with computational (virtual) models to systematically develop, deploy, and validate principles of resilience and autonomous detection and corrective capabilities. With hybrid (physical-virtual) simulation capabilities, RETHi will be able to test a wide variety of SmartHab configurations and operating modes, enabling investigation of a large range of research questions. Our Testbed will also establish RETHi as a focal point for partnerships between private industry, public institutions, other STRI institutes, and NASA.</p>
Status: Active
Description: <p>Supersonic retropropulsion (SRP) has been identified as a potentially enabling technology for human-scale Mars landing systems. However, the accurate description of the complex physical processes and uncertainties associated with the coupling of the bow shock with the plume exhaust, multi-nozzle plume interactions, unsteady flow dynamics, and other aerodynamic interferences pose significant challenges for informing the design of future entry, descent, and landing systems that utilize retropropulsion. This research seeks to develop and apply advanced data-analysis methods to extract fundamental plume physics and sensitivities of multi-nozzle SRP. Knowledge extracted from this analysis will be used to develop a hierarchical modeling framework for predicting quantities of interest with quantifiable uncertainties to support Mars lander powered descent aerodynamics databases and to evaluate SRP wind-tunnel test data. The outcome of this research is expected to achieve significant gains in advancing fundamental understanding of plume physics and establishing improved engineering models to inform the design of multi-nozzle SRP systems, to support the analysis of experimental data, and to facilitate the infusion into related product developments.</p>
Status: Completed
Description: <p>Exposure to altered gravity results in acute sensorimotor impairment, including motion sickness, disorientation, and inhibited postureand locomotion. Astronauts will face severe health risks due to this vestibular impairment when engaging in a more active pilotingrole during future moon or Mars landings and/or during emergency vehicle egress or extravehicular activity (EVA) following landing.They adapt to these new environments over time, but the danger upon initial exposure to the altered gravity remains. Understandingthe underlying mechanisms of this adaptation process would enable sensorimotor impairment prediction and operational mitigation,but it is difficult to directly study the brain's neural mechanisms. My proposed research will result in a novel, experimentally validatedcomputational model of the Central Nervous System’s adaptation to altered gravity. This tool will be capable of predicting theneurovestibular adjustment experienced by individual astronauts, allowing us to investigate operational risks and countermeasureprescriptions including training, rehabilitation, mission scheduling, and more.</p>
Status: Completed
Description: <p>New advancements in spacecraft power generation have driven the development of high-power electric propulsion thrusters. One such technology is the Rotating Magnetic Field – Field Reversed Configuration Thruster (RMF-FRC). Due to RMF-FRC’s pulsed nature, these devices have fully throttleable thrust control over a wide range of specific impulses in direct response to NASA TA 2.2.1.3. This control over performance parameters provides extreme versatility, allowing the RMF-FRC to be the only thruster on board missions that require both a high thrust mode and a high propellant-efficiency mode. One open question regarding the use and further development of RMF-FRCs is the ability for ejected plasma to detach from the accelerating magnetic field lines. While this has been an active and extensive area of research for magnetic nozzle devices, the detachment issues for RMF-FRCs have been dismissed without evidence in previous research work. I propose to investigate the interaction between ejected plasma and applied magnetic fields, specifically in RMF-FRC Thrusters as it pertains to thrust divergence, maximum plasmoid ejection rate, and impacts on spacecraft integration. My study will consist of coinciding experimentation and numerical modeling work leveraging UM’s new RMF-FRC test article, unique test facilities, and previous magnetic nozzle simulation codes.</p>
Status: Completed
Description: <p>A novel approach to the estimation of dynamic systems operating in high-uncertainty environments is proposed. The proposed framework reconstructs the dynamics and measurement modeling found in modern spacecraft navigation filters using measure and possibility-theoretic approaches. Possibilistic filtering represents a new paradigm in parametric estimation techniques. Traditional methods in filtering rely on random process and tuning noise parameters to artificially inflate the uncertainty of a system. This approach is not derived from the physical nature of the system and risks the introduction of subjectivity into filtering solutions. The proposal then reframes uncertainty in dynamic systems as originating from two distinct sources: aleatory, or random, interactions(similar to modern filtering approaches) and epistemic uncertainty, introduced from a lack of knowledge about the system as a whole. Using the mathematical properties of outer probability measures and possibility functions, autonomous navigation in previously unexplored and sparsely characterized environments is facilitated. The development of a novel possibilistic navigation filter algorithm is proposed based on a reformulation of modern navigation techniques. The proposal specifically targets applications of possibilistic filtering to modern navigation challenges, such as terrain relative navigation, multitarget tracking, and robust, fault-tolerant, autonomous vehicle navigation.</p>
Status: Completed
Description: <p>Further understanding and characterization of high-speed flow dynamics in transonic to hypersonic regimes is important for the development, testing, and improvement of complex rocket and space vehicles. Laser diagnostics, such as Filtered Rayleigh Scattering (FRS), provide the opportunity to make non-intrusive in situ measurements without the use of physical probes. However, in order to resolve complex dynamics such as boundary layers and shock wave evolution, MHz-rate diagnostics are necessary. The development of the pulsed-burst laser has enabled high energy pulses to be generated at the rates necessary to make measurements and visualizations of these short time-scale phenomena using FRS. While the feasibility of pulse-burst FRS imaging has been previously demonstrated, quantitative measurements of flow properties at MHz-rates are lacking.<br /><br />In this study, FRS will be extended (i) to higher frame rates up to 1 MHz, (ii) for longer durations up to 100’s of sequential frames, and (iii) with improved capability for multi-parameter measurements. Flow properties such as temperature, velocity, and density will be vital for studying the fundamental phenomena occurring during these flow regimes and for validation of numerical predictions. After validation of the diagnostic approach proposed in this study, extension of the system can be made to study instabilities and flow dynamics in a wide variety of configurations and flow regimes in large-scale test facilities such as at Purdue University and NASA.</p>
Status: Completed
Description: <p>I propose to apply a novel combination of physics-based modeling, optimal design, and rapid prototyping to increase the state of the art (SOA) power level of electrospray thrusters by an order of magnitude from 10 W to 200 W. 100-200 W electric thrusters are ideally suited to support small-satellite class missions, which are receiving increased attention from NASA for their ability to provide worthwhile science returns at low cost. However, SOA electric thrusters have faced trouble accessing this regime. Hall and ion thrusters , for example, suffer poor performance in this range. Electrospray propulsion, a priority technology for NASA[1],offers transformative potential to address this gap but requires further development to overcome design challenges associated with manufacturing uncertainty and identifying optimal designs. To that end, this work will explore novel design methodologies that leverage both predictive modeling and experiment.</p>
Status: Completed
Description: <p>Cold-Tolerant Electronics and Packaging for Lunar Surface Exploration (CTE-PLuS) will lay the foundations for high-performance electronics for future lunar exploration missions. Cold and shadowed regions on the Moon likely contain valuable resources for lunar surface missions. The lunar surface is a challenging environment for electronics and associated packaging used in systems that will search for these substances; with a wide range of temperatures, from a low of 25 K in permanently shadowed regions (PSRs), to a high of 400 K in sunlight, along with large temperature swings. Radiation exposure, modest in terms of total ionizing dose, must be considered for tolerance to single event phenomena. Legacy approaches for robust operation through lunar night and in PSRs have required a warm electronics box (WEB) for thermal control and radiation shielding, which severely impacts system size, weight, power and cost (SWaP-C), complicates wiring, and forces mission designers into highly centralized architectures, constraining science capabilities. To be cost-effective and future-proof, electronics should be realized using commercially-available, low-cost integrated circuit (IC) technologies and standard electronics packaging that are extreme-cold-tolerant, wide temperature range and radiation capable, and highly reliable, without WEBs. The CTE-PLuS team, comprising groups from Auburn University, Georgia Tech. and University of Tennessee, will: (1) implement analog/RF/bias circuitry using 90 nm SiGe BiCMOS, (2) implement analog-to-digital converter (ADC) circuits using deeply-scaled 22 nm SOI CMOS, and (3) realize temperature-tolerant packaging approaches to provide the performance and reliability to achieve LuSTR Topic 3 goals: e.g., degradation less than 20% during 3 years at 70 K.</p>
Status: Active
Description: <p>The technology proposed herein is the design and validation of a transdisciplinary framework that provides recommendations for the design of space architecture that will provide passive behavioral health countermeasures for long-duration spaceflight. The three aims associated with this proposal are 1. Extracting the design language of space architecture as informed by science fiction, historical spacecrafts, and spaceflight participants; 2. Creating a framework for providing and validating design recommendations for multimodal sensory stimulation using adaptive architecture; and 3. Developing a technology prototype from the framework for tactile-visual stimulation as a countermeasure against sensory deprivation. Literature studies, interviews developed from design research protocols, architectural analyses, and human participant experiments are the techniques proposed to conduct the research objectives. One of the largest risks associated with human spaceflight is regarding crew behavioral health and performance, with the risk growing for long-duration missions. For deep-space habitation and planetary travel, NASA has deemed adverse cognitive or behavioral conditions and psychiatric health as a risk that requires mitigation [1]. From the Human Research Roadmap (HRR), BMed-103 and BMed-104 identify the need for validated countermeasures for adverse behavioral conditions and modifications to the habitat to mitigate stressors impacting behavioral health, respectively [1]. At the intersection of these two NASA-identified research gaps, this proposal details a five-year research effort to investigate, design, and validate architectural design strategies that serve as individualized passive countermeasures to mitigate the risk of adverse behavioral health conditions for long-duration exploration missions. The driving value of this proposal is to enable crew for exploration; humans are incredibly resilient and adaptable – how do we make sure that the habitat serves their needs, provides a comfortable home, encourages creativity and exploration, and empowers them to live fulfilling lives? This proposal explores the human aspect of space environments and proposes a technological framework for design methodologies that will serve as passive countermeasures to behavioral health risks by creating an environment that feels like home. [1] Slack, K. J., et al. ""Evidence Report: Risk of Adverse Cognitive or Behavioral Conditions and Psychiatric Disorders."" NASA. 11 April 2016.</p>
Status: Completed
Description: <p>NASA is exploring the idea of sending robotic probes to the ocean worlds orbiting the outer planets. The Europa Clipper, set to launch in 2024, will give us a deeper understanding of the icy surface of Jupiter’s moon Europa. Proposed missions to the surface of Europa, as well as Saturn’s moon Enceladus, are currently being considered as future flagship missions for NASA. Mission designers will be tasked with finding the most fuel-efficient route to these final destinations to save space for the scientific instruments that will probe for signs of life. Current best practices rely on using resonant orbits to perform multiple flybys of other moons to reduce orbital energy before taking advantage of three-body dynamics to approach the target moon. Since the design space is infinitely large, mission designers must often rely on Monte Carlo techniques, simulating millions of random trajectories to find a few that meet mission constraints. This process can be slow, stalling or preventing concurrent engineering efforts. Therefore, fast methods for identifying resonant orbits that reach specific landing sites are in high demand. I have discovered a simple, two-part solution to this problem. First, I apply a standard planar Poincare map in the spatial problem to identify a resonant landing orbit. Next, I generate an "invariant funnel" of trajectories that converge to the orbit, which acts as an attractor. The funnel has a wide mouth, thousands of kilometers wide, that shrinks to a small disc at a landing site only a few kilometers (or less) wide. This proposal seeks to develop these methods into technology that can be used in real-life applications. I will do this by characterizing the dynamical structures that make these methods possible, performing navigation analyses, applying them to the problem of flybys, and producing software and documentation for distribution.</p>
Status: Active
Description: <p>Defect-based single-photon emitters (SPEs) have a significant advantage in quantum sensing and quantum communications because of their robustness to non-ideal environments and atomic-size footprint. This proposal investigates the origins of point defects in wide bandgap semiconductors as well as their interactions with the host crystal. Photoluminescence (PL) spectroscopy is the standard technique for characterizing SPEs but may not capture local lattice effects like strain or vibrational modes that can influence the emission. This proposal uses infrared nano-optic probes to characterize the local vibrational properties that arise from defect SPEs, and spatially correlate with their PL spectral signatures. Scattering-type scanning near-field optical microscopy (s-SNOM) and nanoscale Fourier transform infrared (nano-FTIR) spectroscopy—with full spectral coverage between 5-15 μm and < 20 nm spatial resolution—can examine the behavior of materials beyond their bulk properties and provide vital information for the development of quantum devices. Exciting SPEs with either an ultraviolet (390 nm) or near-infrared (1560 nm) ultrafast pump laser creates a non- equilibrium environment that can be probed with ultrafast nano-FTIR (< 200 fs) and reveal local lattice dynamics and interactions. The outcome of this work will create an efficient, non-destructive method for identifying defect SPEs and uncover information about the local influence of lattice vibrations, which have been theorized as a possible means of deterministic entanglement, an essential component for quantum technologies.</p>
Status: Completed
Description: Creating safe, mobile, and comfortable extravehicular activity (EVA) spacesuit assemblies (SSA) is necessary for successful missions to low-Earth orbit and beyond. The 2020 NASA Technology Taxonomy TX06 identifies technology specific to keeping humans alive, safe, and comfortable in space. The need for advancement in the fit of spacesuits is described in TX06.2: Extravehicular Activity Systems which emphasizes NASA’s desire for launch, entry, and abort (LEA) “suit arm mobility via soft constant volume joints and enhanced patterning” . In the past there have been two primary methods used to achieve these goals: customization and standard sizes. During the Apollo program, suits were customized to fit to the astronauts. This helped with mobility but was not considered for the Space Shuttle Program. The shuttle program manufactured suits in standard sizes. This technique created mobility and sizing issues where smaller women were not able to fit into an Extravehicular Mobility Unit (EMU). NASA eventually only provided sizes medium, large, and extra-large for the shuttle EMUs, even though the original program in 1978 planned on five sizes. However, even if the astronaut was able to fit the length of their arms to a standard size suit arm, their elbow joint didn’t always align with the joint of the suit. Unaligned joints require astronauts to use more energy to perform tasks and can lead to discomfort and injury . This research goal is to create a system that can personalize patterns for SSA components using 3D scans and analytical modeling. The objectives are to design, prototype, and test a system that can personalize patterns for the SSA lower arm (with elbow) using automated landmarked dimensions. This multidisciplinary approach will include engineering and design principles from human integration, anthropometrics and ergonomics, and contact force analysis while also utilizing techniques used in the clothing manufacturing industry.
Status: Active
Description: <p>Solar-powered systems for lunar missions must tolerate and operate in the extreme cold of the lunar night. To ensure efficient and reliable energy conversion and control, power regulators and breakers are crucial, and their survivability at cryogenic temperatures is essential. At the heart of the power regulator and circuit breaker reside power semiconductors and corresponding power electronics technology. The fundamental research goal of the project is to holistically characterize and model target wide bandgap gallium nitride (GaN) transistors in a wide temperature range; and to develop power regulation and solid-state protection techniques empowered by such cryogenic devices in lightweight, fault-tolerant solar-powered systems for lunar missions.</p>
Status: Active
Description: <p>Multifunctional structural materials capable of withstanding the extreme extraterrestrial environments of the Moon, Mars, and other NEOs are needed to establish permanent habitats throughout our solar system. The proposed work aims to develop these materials by first formulating and characterizing reprocessable epoxy thermoset matrices containing dynamic disulfide linkages. These thermoset networks will then be functionalized with various nanofillers to optimize self-healing, radiation protection, and high- rate impact resistance properties. The matrices will then be processed with native lunar regolith simulant to produce strong, tough polymer concretes to achieve optimal structural capabilities and minimize material that would need to be transported to proposed extraterrestrial habitat locations. Mechanical testing will be conducted using conventional techniques including dynamic mechanical analysis, double torsion fracture toughness, and uniaxial compression, as well as with a high frequency rheological technique using the quartz crystal microbalance in which the research team are specialists. The MHz frequencies used are relevant to determining correlation with high-rate impact resistance, computational simulations, and fracture behavior at cryogenic temperatures. Testing will be performed across a very wide temperature range, with emphasis placed on optimizing properties at cryogenic temperatures relevant to the lunar surface. The proposed research directly addresses the goals of TABS elements 12.1.1 (Lightweight Structural Materials) and 12.1.4 (Materials for Extreme Environments) as described in the Technology Roadmap. The developed matrices will serve as lightweight matrices for composite structural materials possessing self-healing and other functionalities specifically requested in level 4 TABS elements 12.1.1.2 and 12.1.1.4. The matrices will also be designed to survive in extreme extraterrestrial environments for habitats, addressing goals for "Materials for Extreme Environments" in 12.1.4.</p>
Status: Completed
Description: <p>Current and future greenhouse gas emissions will have a profound impact on the future state of our climate. As such, quantifying their emissions is critically important for both projecting future climate and assessing the impact of environmental policy. Many of the human-caused greenhouse gas emissions come from point sources. Observing and quantifying these sources necessitates densely spaced measurements. In response to this, there has been a proliferation of dense observing systems (e.g., geostationary satellites) that allow us to study these sources. However, it becomes computationally intractable to relate the observations back to the sources for these dense observing systems. This project aims to develop a computationally efficient emulator of a full-physics model, allowing us to fully utilize the measurements from these dense observing systems. The combination of these of dense observing systems and our high-fidelity emulator will allow us to study greenhouse gas point sources that are critically important for future climate.</p>
Status: Completed
Description: <p>This proposal describes an experiment designed to measure the wave attenuation characteristics of two-phase flows for application to rotating detonation engines (RDEs). The experiment described within was conceived to help address an important issue with current generation RDEs; it is possible for high pressure fuel-laden exhaust gasses within the combustor to back flow into the injector system and reach the oxygen manifold. This event could result in unintended combustion within the manifold system. A solution to prevent this back flow event is therefore required.</p> <p>Since gas/liquid propellant combinations are used in numerous rocket combustors, understanding the attenuation characteristics of two-phase mixtures is of immediate interest to the community. Because the attenuation characteristics of two-phase mixtures are poorly understood, these physics are the prime motivation for the proposed research. The proposed experiment will help elucidate these attenuation characteristics by studying how the pressure of the detonation wave decreases as a function of distance.<br /> <br /> A cylindrical test chamber, open to the atmosphere at the bottom, will be filled from the top with a water mist generated with a commercial atomizer so that the droplet field is well characterized. A predetonator with mix and ignite a fuel air mixture and direct the resulting detonation wave into the chamber. Pressure transducers along the height of the cylinder will measure static pressure of the air/water mixture within the cylinder as the detonation waves travel in from the bottom. Trials would be run to study the effect of varying gas/liquid void fractions, drop sizes, and detonation strengths on wave attenuation.<br /> <br /> The data from these experiments can help minimize injector pressure drops to mitigate catastrophic back flow events. Specifically, data from the proposed experiment would be leveraged to inform part geometry and desired flow conditions that effectively attenuate blow back events, thereby isolating the injectors from the exhaust gasses.</p>
Status: Completed
Description: <p>The addition of two-dimensional (2D) nanomaterials into polymers has proven to tailor their properties such as thermal conductivity, electrical conductivity, and mechanical strength. 2D materials, such as Boron Nitride Nanoplatelets (BNNP) and Graphene Nanoplatelets (GNP), are especially suitable as reinforcement due to their outstanding specific surface area, which contributes to a strong interaction with the polymer matrix. A significant challenge with nano-sized 2D fillers is their agglomeration, which has detrimental effects on the nanocomposite properties by limiting the interfacial structure between the filler and polymer matrices. Freeze-Drying (FD) is a fabrication technique that overcomes agglomeration challenges by assembling nanomaterials into rigid free-standing three-dimensional (3D) architectures or foams. The high surface area of 2D materials facilitates the construction of networks that provide effective phonon and mechanical stress transfer. It is hypothesized that the integration of one-dimensional (1D) materials, such as Boron Nitride Nanotubes (BNNT) and Carbon Nanotubes (CNT), into 2D material-polymer nanocomposites, will provide additional stress and phonon transfer conduits. The proposed research aims to engineer hybrid 2D/1D material foam-polymer composites with enhanced thermal properties while exhibiting low density and high mechanical strength via FD fabrication. 2D materials, such as BNNP and GNP, will be integrated into polymers, such as Polydimethylsiloxane (PDMS) and Epoxy. Adding 1D materials, such as BNNT and CNT, into these structures is expected to enhance mechanical and thermal properties further. An analytical framework that dictates mechanical and thermal properties of polymer nanocomposites in terms of composition, processing parameters, and microstructure will be developed. This framework will incorporate thermodynamic relations to describe processing factors effect on the 2D foam architecture. Multi-length scale mechanical characterization and stress modeling at the node-branch of the nanocomposites will elucidate load transfer and failure mechanisms. Thermal characterization and modeling will determine the influence of the microstructure on phonon transport.</p>
Status: Completed
Description: <p>The objective of this project is to identify the physical origin of drain noise in high electron mobility transistors (HEMTs) and thereby establish a pathway towards millimeter-wave amplifiers with a quantum-limited noise figure. Low noise amplifiers based on HEMTs are ubiquitous in space science and technology. While the noise mechanisms in these devices have been studied since their original development in the late 1980s, the origin of the noise associated with the hot electron gas in the channel remains a topic of debate. I will address this long-standing challenge using a novel technical approach that permits a parameter-free microscopic description of the fluctuations of hot electrons. With the knowledge gained from this approach, predictions regarding device optimization can be tested to create the next generation of low noise microwave amplifiers operating near the quantum noise limit.</p>
Status: Active
Description: <p>Emerging high intensity nuclear and chemical combustion based spacecraft power and propulsion systems will need waste heat rejection radiators that can operate efficiently at high temperatures and heat fluxes. This project seeks to meet this need by developing and experimentally demonstrating high temperature additively manufactured (AM) monolithic metal heat pipe radiators (HPRs). These HPRs would be produced from corrosion-resistant materials in a single AM process that would form integral vascular vapor passages, porous liquid-wicking structures, and fin sections. Embedded heat pipes would passively circulate high temperature phase-change heat transfer fluids. Open-source multiphysics radiative, thermal-fluid, and structural optimization tools will be developed and shared to guide high performance designs that can withstand mechanical loads from flight and long-term thermal stresses.</p>
Status: Completed
Description: <p>This work aims to develop an atomic vapor notch filter functioning at the third harmonic of the high-power and robust Nd:YAG laser (355 nm). Vapor filters are a critical component of several laser diagnostic techniques due to their deep, narrow, and tunable light absorption capabilities. Most notably, these filters have enabled measurements of temperature, flow velocity, aerosol properties, and electron temperature and number density through applications spanning space technology, including remote sensing, electric propulsion, re-entry, hypersonics, and combustion.<br /> <br /> However, current filtering technology is limited to wavelengths which are either unsafe for the human eye, lack the scattering signal strength necessary for longer range measurements, or are challenging to generate. The proposed project looks to overcome these limitations and improve our diagnostic capabilities by developing a barium vapor filter functioning at an easily accessible wavelength outside the retinal transmission region. This filter would benefit from increased signal strength and eye safety, decreased sunlight background, negligible ozone absorption, rapid tunability, and easy integration into any third harmonic equipped Nd:YAG system. While this technology could augment several established diagnostic techniques for propulsion and hypersonics ground testing, these parameters are particularly advantageous for laser remote sensing—namely lidar (light detection and ranging) systems, which use scattering signals to measure atmospheric parameters. Lidar improvement has been named a priority under NASA TABS element 8.1.5. If successful, this project would enable higher precision and safer atmospheric profiling on our own planet and other celestial bodies.<br /> <br /> While currently at a low TRL, previous studies provide confidence in this new and innovative approach. Still, filter development and implementation present engineering and scientific challenges. These will be addressed through 1) fabrication and testing of a dense barium vapor source, 2) an in-depth experimental and modeling study of barium kinetics using absorption measurements, and 3) ground-based and airborne atmospheric lidar measurements. The interactions with NASA lidar expertise and facilities provided by this fellowship would greatly extend the impact of this filter technology for space applications.</p>
Status: Completed
Description: <p>The proposed research aims to develop novel guidance algorithms using machine learning models trained by research-grade computational fluid dynamics (CFD) simulations to enable more robust delivery of high-mass, low-ballistic-coefficient space systems to the outer planets via aerocapture. Specifically, we propose to investigate vehicles with hypersonic inflatable aerodynamic decelerators (HIADs). Uncertainty in the planet's atmospheric model, the chemical kinetic models for that atmosphere, and the vehicle's state and model parameters will be considered. The neural-net-based models will capture key aerodynamic and aerothermodynamic phenomena that occur during aerocapture. We plan to improve the aerodynamic models typically used in the state-of-the-art fully-numeric, predictor-corrector guidance scheme by replacing its iterative process with an neural-net-based model to incorporate high levels of uncertainty and reduce on-board computation time. The uncertainty in the chemical kinetic model used in the CFD simulations will be addressed, and potential improvements to the chemical kinetics will be investigated. This work advances the areas TA 9.1.4: Deployable Hypersonic Decelerators and TA 9.4.5: Modeling and Simulation in the NASA Technology Roadmap TA 9: Entry, Descent, and Landing.</p>
Status: Completed
Description: Hybrid rockets have been identified as a potential technology for cost effective delivery of micro and nano satellites into Lower Earth Orbit (LEO). Compared to solid rockets, hybrids are far more maneuverable, while simultaneously maintaining a simplistic design compared to liquid engines. However, achieving high fuel regression rates has been a challenge due to the lack of fundamental understanding of the diffusion-controlled combustion that occurs in the motor. Lack of high-fidelity modeling capabilities have resulted in reliance on costly test campaigns for design iteration. To address this issue, this project seeks to develop an understanding of the underlying mechanisms parametrizing hybrid fuel burning behavior by developing a physics informed machine learning model. Physics informed machine learning is a novel approach that has been shown to enhance generalizability and reduce overfitting, in addition to requiring less training data than traditional machine learning approaches. The developed model will be used to optimize experimental conditions by using Bayesian statistical setting. Training data will then be collected using additively manufactured fuel grains in a small scale optically accessible 2D hybrid rocket motor. Finally, model fidelity will be verified by completing a test campaign focused on 3D hybrid rocket motors capable of approximating the performance of LEO launch vehicles. The creation of a generalizable high-fidelity model will enable the efficient design of hybrid rockets, bringing down their development costs.
Status: Completed
Description: Advances in additive manufacturing (AM) have allowed for the design and development of 3D printed spacecraft propulsion systems. Several cold gas propulsion systems have been successfully printed with composite materials, allowing for components such as propellant tanks, routing passages and nozzles to be printed as one unit. This approach allows the designer to make more efficient use of the allocated volume. With the recent development of liquid monopropellants for small satellites, such as AF-M315E, different printing materials are required. This is due to the compatibility with the monopropellant as well as the need to withstand the much higher pressures required for liquid propulsion systems. However, a current limitation with using additively manufactured structures as pressure vessels is their survivability under load. This can lead to overdesigned tanks which drive up mass, cost, and development time. This research proposes developing a design methodology for generating additively manufactured high-pressure tanks for spacecraft propulsion systems. The methodology will be based on Generative Design (GD) coupled with Design for Additive Manufacturing practices (DfAM). Based on a set of objectives and constraints set by the designer, GD will produce a suite of preliminary designs for the user to evaluate. Once a concept is selected, a parametric model is produced and optimized to meet the AM manufacturability requirements. Analysis and validation of this method will be done via the design of a 1U propellant tank. In-house printing capabilities will be leveraged to print prototypes and perform pressure burst testing. The key challenges that need to be addressed in this research have been identified as follows: 1) development and implementation of the multi-objective optimization algorithm for the conceptual design phase, 2) identification of the best suitable filter for selecting the final concept based on full automation vs designer involvement and 3) automation of the parametrization of the selected concept. The capability of efficiently designing AM high-pressure vessels is vital for the adaptation of the AF-M315E propellant for future missions that require increased propulsion performance. This research can be viewed as a steppingstone to 3D printed satellites with the propulsion system designed into the structure. This work will be applicable to any AM material of interest as well as other propulsion components.
Status: Active
Description: <p>Lunar dust, with its chemical reactivity, electrostatic charge, and potential magnetism, poses a serious threat to astronauts and equipment on the Moon’s surface. To address this, the project proposes developing structured coatings with anisotropic surface features and electrostatic dissipative properties to passively mitigate lunar dust. By analyzing lunar dust-surface interactions at multiple scales, the team aims to optimize the coatings' surface structures and physical properties, such as Young’s modulus, electrical conductivity, and polarity. The project will examine tribocharging, external electric fields, and the effects of particle shapes and sizes. Numerical sensitivity analyses will complement simulations to better understand lunar dust dynamics. Once fabricated, the coatings will be tested under simulated lunar conditions. The team will employ a state-of-the-art nanoscale force spectroscopy system, using atomic force microsope (AFM) microcantilevers functionalized with regolith to measure dust-surface interactions. Additional experiments will assess particle adhesion and removal, with scanning electron microscopy used to analyze remaining dust. This project aims to provide insights into surface structure effects on dust adhesion, guiding the creation of lightweight, durable coatings for effective dust mitigation. The findings will foster collaborations with NASA and the aerospace industry, while offering training opportunities for students entering the field.</p>
Status: Completed
Description: <p>The proposed research effort will provide autonomous landers the capability to land on rugged terrain, having applications space applications for lunar/planetary landers. The use of adjustable landing leg lengths, stereo vision and artificial neural networks (ANNs) to map terrain at the landing site and determine a target landing vehicle state (target position, orientation, and landing leg length), and an ANN-driven fuel optimal controller to achieve the target landing state will be investigated through simulation and hardware implementation. Target landing zones on lunar missions have traditionally been restricted to large plains/plateaus due to restrictions on lander guidance precision and HDA capabilities. Even with the improved precision that came with investigations of optical navigation for HDA using ANNs, selected landing sites are limited to geometrically simple areas. These restrictions limit opportunities for scientific discovery on lunar missions by confining payload delivery to these specific regions. A landing system that is capable of successful delivery to virtually any terrain would vastly improve opportunities for exploration and discovery on other terrestrial bodies. A Stereo Vision-ANN based landing configuration determination system (LCDS) with ANN optimal controls can provide these successful deliveries, providing new opportunities for scientific discovery in lunar regions of geometrically complex terrain. The proposed LCDS includes an ANN trained to determine a target vehicle state based on a pair of images from a stereo vision system pointed at the terrain. This target vehicle state includes a target vehicle position, velocity, orientation, and landing leg length. This target state is then used by the ANN fuel-optimal controller to land the vehicle. The tools required to investigate the proposed research questions include (1) a tool to generate training and test data for the LCDS, i.e. data sets containing image pairs given a specified camera distance linked to a target vehicle state; (2) a tool to generate fuel optimal trajectories to train and test the ANN optimal controller, i.e. state-action pairs; (3) a tool to simulate the lander dynamics and implementation of the LCDS and optimal controller; and (4) a hardware implementation of a stereo vision system with LCDS and optimal control. Tool 1 will be based on the image generator presented in previous HDA works, and Tool 3 will be developed in MATLAB/Simulink. Tool 2 is already available as free MATLAB toolboxes (e.g. GPOPS-II, OpenOCL, etc.). Tool 4 will be developed in parallel with the other tools. One example of a low-cost (<$2,000) hardware implementation option is a 6 Degree of Freedom robotic arm and a sandy test bed. Simulation test-cases will be chosen such that a preliminary assessment of the system performance and robustness can be made, giving an initial answer to the research question. Tool 4 serves as a technology demonstration of the LCDS and ANN optimal controller, allowing for investigation of the research question in the context of a real application.</p>
Status: Completed
Description: <p>Localization within an environment is often critical to mission success, though it typically requires a priori information, such as an environmental feature map, that can be expensive and time-consuming to obtain. By minimizing the dependency on a priori information, budgets and timelines can be reduced while, in tandem, expanding the capabilities of exploration systems. Recent developments in random finite set (RFS)-based simultaneous localization and mapping (SLAM) show promise for autonomous navigation and exploration. Creating an RFS-based SLAM framework for space-based navigation will minimize the dependence upon a priori information and external communications, while simultaneously producing an architecture that is robust to common issues, like erroneous measurements and mismatches in the expected and observed features. Unfortunately, existing feature modeling approaches utilize simplistic techniques that often assume features to be point-sources with non-representative probabilistic models. These modeling decisions only partially reflect the underlying, physics-based processes and severely limit the information processed. Developing improved modeling techniques that incorporate probabilistic and extended feature considerations will allow autonomous systems to be more thorough in representing environmental features, producing richer information for navigation, exploration, and interaction. RFS-based SLAM approaches, however, are not traditional for navigation and thus lack much of the robustness and efficiency that is paramount to successful navigation. By extending the architectures to include factorized forms and consider parameters while also examining methods to reduce the burden of a multitarget update, robustness and efficiency can be addressed. The proposed research will develop an efficient and robust state-of-the-art RFS-based SLAM framework for autonomous navigation and extend the capabilities of current feature modeling techniques by introducing novel physics-based models for features of finite extent. Carrying out the proposed research will lead to a navigation framework that is applicable to all manner of space platforms will be realized.</p>
Status: Completed
Description: <p>The Fast Affordance Manipulation Execution (FAME) project aims to improve dexterous robot manipulation by providing a sparse, concise, and expressive representation of object affordances that can achieve multiple concurrent objectives and be executed quickly, reactively, and safely alongside humans on-board spacecraft. To achieve this, sparse and robot-generic affordance templates will be extended with computationally quick and expressive potential field controllers to represent affordance templates. Quick computation of potential field controllers and dynamic combination of control commands through nullspace projection will make affordances quick to execute. This representation also supports multi-objective and reactive behaviors, which are crucial for dexterous manipulation in dynamic environments, especially when robots are expected to work safely alongside humans on-board spacecraft. FAME will address many open questions in dexterous manipulation---specifically real-time computation, reactive and multi-objective behaviors---while emphasizing safety for operation in space technology applications such as the International Space Station or spacewalks.</p>
Status: Completed
Description: <p>A key challenge to planned crewed missions beyond low-Earth orbit is the infeasibility of regular resupply from Earth due to physical distance and launch economics. As such, controlled environment plant production is poised to supply a greater portion of crew diet. Crew time is valuable, however, and crops are also subject to contamination from human interaction. Thus, there is a pressing need to develop autonomous food production systems for use in space that can quantify and minimize the risk of crew malnourishment. Digital twin technology consisting of 1) a virtual model of a physical system, and 2) integration of the model with a real-time sensor network, can address this need by autonomously maintaining controlled environment plant production within control limits. The first objective of this proposal is to identify nondestructive methods for predicting shoot biomass at harvest and carotenoid content of lettuce plants grown in controlled environments. This will be done by developing correlations between hyperspectral image data of plants with values determined by destructive analysis. The second objective of this proposal is to adapt a functional 3-D plant model to be updatable with real-time sensor data and to develop a control scheme with the model for maintaining optimal growing conditions. This will be performed by combining time-independent submodels, then integrating time-dependence by recalculating parameters in each time step. The control scheme will be developed using model-predictive control. The proposed work will produce digital twin components that will raise autonomous space food production technology to a proof-of concept level (TRL 3). Ultimately, the proposed work will reduce the need for resupply of future long-duration crewed missions and lay the groundwork for future digital twin technology development of biological systems.</p>
Status: Completed
Description: <p>Powered descent on the Moon and Mars relies on rocket exhaust plumes to impinge on the ground covered with granular soil, creating dense particle clouds and high-speed ejecta, which can pose danger to the spacecraft and astronauts aboard. A major challenge in this area is the lack of high-quality time-resolved experimental datasets for unit experiments or ground tests that can illustrate particle-particle and particle-gas interactions in extreme conditions. To better understand these processes, I plan to use experimental methods to unveil the physical mechanisms that occur in plume-surface interaction. My objectives to achieve this goal are as follows: i) Continue the development of the particle-laden high-speed jet facility in our laboratory to study supersonic flows, ii) investigate particle physics and its effect on flow properties prior and during impingement, and iii) collaborate with NASA facilities for ground tests. The proposed research plan will support the following Level 2 NASA Technology Areas (TA) areas: TA 7 – Exploration Destination Systems and TA 9 – Entry, Descent, and Landing (EDL).<br /> <br /> Using a combination of high-speed flow diagnostics (focused Schlieren and Shadowgraph imaging) as well as high-speed velocimetry (ultra-high-speed particle tracking velocimetry and particle image velocimetry), we will obtain high-fidelity time-resolved experimental data that will reveal how particles travel during plume-surface interaction in landing-relevant conditions. Specifically, we will gain information on particle velocity, acceleration, and directionality, which will help NASA scientists design spacecraft to mitigate plume ejecta risks, as well as, help validate their simulations for plume impingement dynamics. The technology readiness level (TRL) for ejecta dynamics during power descent will increase from 2 (limited experimental data available) to 3 (with successful unit experiments), and it may also reach 5 (with successful ground tests in a relevant environment).</p>
Status: Active
Description: This research effort seeks to advance detection systems to enable versatile, miniaturized lidar and laser communication instruments suitable for small satellite platforms. By exploring low-cost detector technologies, along with field programmable gate array (FPGA)-based reconfigurable readout and processing circuits, this project seeks to develop a prototype receiver system that can enable a range of lidar and laser communication applications. This work builds off of the ongoing Concurrent Artificially-intelligent Spectrometry and Adaptive Lidar System (CASALS) project at NASA GSFC and the CubeSat Laser Infrared CrosslinK (CLICK) project at MIT. A novel, low-cost receiver will be developed based on the work on CASALs and CLICK, including the system modelling and simulation and the design of the FPGA-based reconfigurable readout circuits.
Status: Active
Description: <p>The recently established NASA Artemis mission reflects the growing interest of sending humans to colonize the Moon and Mars, and to explore more of our solar system. However, long-term space exploration requires technologies that can protect astronauts and space equipment from extreme space environments, such as extreme temperatures and carcinogenic radiation. While Carbon nanotubes have been investigated as space materials, boron-nitrogen nanotubes (BNNT) are just as mechanically strong, and can provide higher thermal resistance and radiation-shielding capabilities to address these harsh conditions. Furthermore, BNNT and BNNT polymer composites display unique piezoelectric properties that are scalable and useful in vibrational sensors and soft actuators. Experimentally finding the ultimate set of modifications and geometries that can produce BNNT and BNNT-polymer composites with the best properties under extreme space conditions may be infeasible, costly, and time-consuming. This project thus aims to accelerate this optimization process using virtual prototyping: We will employ computer simulations and first-principle calculations to understand the mechanisms governing the properties of multi-functional BNNTs and their composites. This fundamental knowledge, along with machine-learning algorithms, can then search for the set of parameters that give the best overall properties of these multifunctional materials for extreme space conditions. Moreover, this project can inform the design of theoretically new structures with mechanical, piezoelectric, and radiation-shielding properties superior to current state-of-the-art aerospace materials. If awarded, I would like to request a grant start date of August 23, 2021, which aligns with the start of the Fall semester at my host institution, Rice University.</p>
Status: Completed
Description: <p>Lithium-ion batteries (LIBs) have become ubiquitous in daily life but do not perform well at the low temperatures encountered in space and planetary exploration. This is a result of the relatively low capacity and poor diffusion within the graphite anode in LIBs, as well as electrolyte limitations. Much work has focused on replacing graphite with materials that alloy with lithium to achieve higher energy density. However, very little research has focused on understanding and developing high-capacity alloy anode materials specifically designed for low-temperature performance. My research aims to understand how alloy anodes perform and evolve in rechargeable lithium batteries at low temperatures. This work will provide fundamental insights into the relationship between temperature, morphology, and performance of alloy anodes, as well as a pathway towards using these materials in high-energy, low-temperature batteries. The specific research tasks include 1) investigating the diffusion and morphology changes and the overall electrochemical behavior of alloying anodes when cycled at low temperature, 2) using alloy materials to seed the deposition of lithium metal with high efficiency at low temperature, and 3) fabricating full cells that achieve high specific energy and energy density for over 200 cycles below -40 C. Scanning electron microscopy and cryogenic focused ion beam SEM will be performed on electrodes to understand how temperature and cycling impacts the morphology of both alloying anodes and alloy-seeded lithium metal anodes. Cryogenic transmission electron microscopy will reveal the formation and evolution of the solid electrolyte interphase at low temperatures. I will also quantify changes in diffusion and its effect on electrochemical performance at low temperature using the galvanostatic intermittent titration technique and galvanostatic cycling, respectively. This research will elucidate the relationships between temperature, morphology, and battery performance and will be an important step towards engineering high-energy batteries specifically designed for low-temperature space applications.</p>
Status: Active
Description: <p>The proposed research involves the synthesis and characterization of novel energetic cocrystals of ammonium nitrate as a potential green alternative to ammonium perchlorate composite propellants. The research will proceed in three phases; (i) development of a model for the identification of intermolecular interactions that favor cocrystal formation with predictable properties; (ii) synthesis of targeted ammonium nitrate energetic cocrystals; (iii) full characterization of crystalline and energetic properties of new materials via x-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic vapor sorption (DVS), mechanical sensitivity testing, and thermochemical calculations via Cheetah analytical software. Preliminary results include a series of three novel ammonium nitrate cocrystals used to identify a series of potential energetic cocrystallization targets. The proposed research aims to address the specific goals under TABS 1.1.1 of producing solid rocket propellants with higher performance, lower cost, and lower environmental impact than conventional propellants.</p>
Status: Completed
Description: <p>To address the challenge of computational complexity in entry, descent, and landing guidance algorithms, I will develop efficient methods to compute large diverts at a distance at least twice the height at powered descent start, while respecting all spacecraft constraints and minimizing fuel consumption. Current technologies can compute constraint-satisfying and fuel-optimal diverts but these methods can only be applied to problems with linear state constraints. In addition, current guidance solutions to problems larger than 1000 solution variables are computationally infeasible on flight processors. My work will mitigate these challenges by developing a near-term implementable guidance algorithm capable of solving the fuel-optimal solution for large diverts, as well as develop algorithms for future missions requiring time-varying constraints and complex maneuvering. Near-term development will focus on reducing the computational costs of the Interior Point Method for solving multi-constrained optimization problems. The algorithm will be implemented optimally and tested on a flight computer in a high Earth altitude, full-scale demonstration. Results from the full-scale demonstration and simulations will be used to verify the technology for the Mars Sample Return mission. Long-term developments will include the extension of optimization methods to solve guidance problems that are currently unsolvable for a globally optimal solution. The final algorithm will be capable of autonomously maneuvering in complex, multi-agent environments. These developments in high-level autonomy will enable large diverts for pinpoint landing of the Crewed Mars Surface Mission. Research in computationally-efficient methods for solving large divert guidance problems will directly support TABS 9.2 Descent and Targeting Technologies in the NASA Technology Roadmap. The proposed project will advance large divert guidance to TRL 6 by formulating methods for solving multi-constrained optimization problems to improve runtime on current flight processors.</p>
Status: Completed
Description: <p>Covalent organic frameworks (COFs) are an emerging class of crystalline, porous polymers, constructed by covalently linking organicmolecules into extended networks with highly organized 2D or 3D structures. COFs have uniform and tunable nanopore sizes as wellas high surface areas, rendering themselves ideal for separation, adsorption, catalysis, and many other applications. The existingsynthetic methods to produce COFs generally yield insoluble and unprocessable powders which limits their implementation for realworldapplications. This proposed work will focus on developing adaptive 2D COFs by molecularly incorporating functional groupsthat can respond to heat, UV light, or other external stimuli. More specifically, these functional groups are capable of reversiblyswitching between a neutral and charged state. In their charged states, these groups would exhibit intermolecular electrostaticrepulsion to suppress the attractive forces between 2D COF layers, thereby resulting in suspensions of self-exfoliated layers withimproved processability. Once the 2D COF sheets have been processed into a film, these functional groups can be deactivated totheir neutral states, thereby re-establishing the strong interlayer attractive interactions and significantly enhancing the material’smechanical and chemical stability. The processability and crystallinity control enabled by the proposed method will be harnessed toproduce 2D COF membranes for water purification. The highly directional and uniform nanopore channels inherent to 2D COFs yieldexcellent salt rejection and theoretical permeances several orders of magnitude higher than commercial reverse osmosis membranes.Enhancing the processability of these COF-based materials via stimuli-responsive functionalization is a critical step toward realizingtheir full potential. Advancing water recycling technology with these novel materials could lead to a new membrane-based module withsuperior performance and energy efficiency compared to the existing water recovery systems vital for space habitation.</p>
Status: Completed
Description: <p>Solar Energetic Particles (SEPs) are among the most hazardous transient phenomena of the solar activity. Accelerated during solar flares or in shock wave fronts of coronal mass ejections (CMEs), SEPs propagate through the heliosphere and interact with the space environment. Representing hazardous radiation, SEPs may affect health of astronauts in the open space and create difficulties for the future space exploration. Therefore, improvement of the SPE forecasts using machine-learning technologies is a very timely task. In order to discover relationships among precursors and properties of the SPEs, and associated observational data, the incoming data and metadata need to be processed and integrated into a comprehensive database. This database will enable the development of targeted applications of modern machine learning and data analysis techniques to enhance reliability of the SEP forecasts, proposed in this investigation. The primary objective of the research is to enhance predictions of solar energetic particles (SEP) by implementing automatic data characterization and machine-learning tools. The project pursuits two main goals: 1) development of an online-accessible automatically-updated database that integrates the solar and heliospheric data, metadata, and descriptors related to SPEs; 2) development of robust all-clear forecasts of SPEs with low false-alarm rates, and adapted to operational data availability. Using the developed data resources, tools and methodologies, the team will achieve a transformative change from the current low Technology Readiness Level (TRL) to high-TRL in these tasks.</p>
Status: Active
Description: An efficient general encoding scheme for transferring photonic quantum states to physical quantum memories would provide a physical realization of quantum optimal receiver designs, whose performance can achieve orders of magnitude improvement over current communications and sensing technologies. The objective of this proposal is to develop such an encoding scheme through investigating novel light-matter Hamiltonians, like the Jaynes-Cumming Hamiltonian, the non-Gaussian Kerr-like gate Hamiltonian, among others. This investigation will be followed by in depth physical modeling of the performance when such schemes are applied to quantum optimal receiver designs, and optimization based on results. Many of the quantum optimal receiver designs have been developed by NASA for application to deep space quantum communications in the low-photon number regime. Their physical realization would provide access to highly efficient laser communications systems for future NASA missions. The realization of this photonic quantum state encoding receiver would also prove highly valuable for entanglement enhanced long baseline astronomy, as well as sensitive earth and planetary science observations, maximizing the ability to extract available information from incoming light. Outside of NASA, this technology also has many cross-over possibilities, as quantum efficient sensing and communication would prove greatly useful to humanity.
Status: Active
Description: NASA’s Human Research Program defines several hazards of human spaceflight, including radiation, isolation, distance from earth, gravity fields, and hazardous/closed environments. In particular, closed environments present a challenge for the design of environmental control and life support systems (ECLSS) and the subset of ECLSS that includes management of the human thermoregulation system. These challenges are amplified as missions become more complex, farther from earth, and include increasingly complex extravehicular activity (EVA). Over the last 58 years, over 250 people have participated in EVAs during spaceflight. Since the Apollo missions, crew members have worn a cooling garment underneath the pressurized EVA suit to regulate the temperature of the in-suit environment. Current Liquid Cooling and Ventilation Garments (LCVG) have not changed significantly since the Apollo era and are therefore not optimized for current microgravity missions, the Artemis program, or future crewed missions to Mars. New numerical models could provide a basis for the generation of novel thermoregulation designs and technology, especially in more complex missions. The planned research focuses on the intersection of human thermoregulation modeling and the impacts of spaceflight on the human body. A new thermoregulation model of the human, focused on the limbs, will build off of 60 years of human thermoregulation modeling, derived from the METMAN and Wissler models. The proposed model will include all aspects of human thermoregulation, including metabolic heat generation, heat transfer within the body, and heat transfer to the atmosphere, along with modeling of the cooling garment layers of the spacesuit. The model will focus on creating detailed blood flow and LCVG fluid flow path modeling and optimization, while incorporating three-dimensional variability and view factor impacts for thermal radiation. Model validation will use data published in open literature. The impact of a new validated human thermoregulation model has the potential to provide the theoretical basis for engineering new LCVG garments with innovative cooling technologies for next-generation EVA suits.
Status: Active
Description: Microgravity, radiation, a lack of materials, and a confined environment have unprecedented detrimental effects on astronaut health. Medical therapeutics are a crucial health support system that will need to be re-evaluated for long duration space flight. Pharmaceuticals degrade from radiation, medicine can run out, and more medicine cannot be provided on demand. One option is to use a biomanufacturing platform for pharmaceutical production via synthetic biology. This platform has several advantages over contemporary mechanochemical techniques, including low mass, low power requirements, low volume, and high flexibility/ adaptability. However, a hurdle to the successful operation of this platform is the effect of the space environment, which can alter cellular production. Tight regulation of production is essential to successfully biomanufacture pharmaceuticals in the face of this dynamic environment. Therefore, I am proposing two research objectives that will bring this nascent technology from Technology Readiness Level 2 to Technology Readiness Level 4. The first objective is to use genetic circuits to regulate the biomanufacture of therapeutics in the model synthetic biology organisms Escherichia coli and Pseudomonas putida in response to dynamic space environmental conditions. The second objective is to extend this regulation of therapeutic biomanufacturing to more complex environments and hosts, namely in co-culture with lung epithelial cells, and in Lactuca sativa (lettuce). These two objectives fulfill an innovative approach to therapeutic bioproduction that is specifically tailored for space exploration, to minimize potential risks to astronauts and off-nominal health events. I believe that I am ideally suited to tackle these objectives and produce the proposed work due to my unique background that combines mathematical modeling and experimental biomedical engineering. The proposed work is significant to space research and engineering because it will lay the groundwork, and prove possible, on-demand production of therapeutics for deep space missions.
Status: Active
Description: GRX-810 is a promising new NASA-developed metal alloy that is manufactured through a 3D metal printing process with oxide dispersion-strengthening. Experiments have shown that this material is able to withstand extremely high temperatures of over 2000 degrees fahrenheit and can provide over a 1000-fold increase in creep resistance compared to commonly used polycrystalline wrought Ni-based alloys [1], making it an exciting candidate for usage in aerospace parts subject to extreme temperatures and loading conditions such as rocket engines and turbine blades. This study proposes a comprehensive computational modeling project focused on the mechanical behavior of GRX-810 with three key components: developing a material model to characterize the performance of the metal, modeling long-term creep behavior under sustained stress, and examining material behavior during the manufacturing process via 3D metal printing. As a preliminary process, the General Viscoplasticity with Potential Structure (GVIPS) model [2] will be implemented in code to reproduce known results for classical materials such as the TIMETAL 21S titanium alloy [3]. Once this model is confirmed to reproduce accurate results, GVIPS can then be used as a foundation to develop the viscoplastic material model for GRX-810, which will allow for characterization of essential material properties such as strength, ductility, hardness, toughness, and fatigue resistance. This newly created model will be validated with physical experiments performed using uniaxial and multiaxial loading, hardness, Charpy, and monotonic and cyclic loading tests. Then, creep behavior describing gradual time-dependent deformation of GRX-810 under constant stress will be modeled. This is a critical property of the material, given its application in high-temperature environments with long-term loading; the developed model characterizing creep will be able to predict potential material failures of structures utilizing GRX-810 at large time scales, and will also enable the exploration of methods to enhance creep resistance through optimized manufacturing techniques. Lastly, the comprehensive material model for GRX-810 will be implemented into simulations of the 3D metal printing process with incorporated heat effects, and material behavior under extremely concentrated thermal loading will be examined to gain insights on material yielding and plastic deformation during manufacturing. The effects of different laser scanning speeds, paths, and temperatures on stress evolution and material deformation can be investigated, which will enable optimization of these critical manufacturing parameters to minimize material defects and enhance resulting material performance. Through this comprehensive approach, this project not only advances the understanding and application of GRX-810 but also establishes a versatile framework for characterizing and optimizing the manufacturing processes and material properties of future groundbreaking materials designed for extreme aerospace conditions.
Status: Active
Description: Will lead the Quantum Pathways Institute, focused on advancing quantum sensing technology for next-generation Earth science applications. Such technology would enable new understanding of our planet and the effects of climate change.
Status: Active
Description: Monitoring, understanding, and mitigating the rapid atrophying of muscles that occurs during spaceflight is key to preserving human health during space missions and extending the duration of human-manned missions. Hence, technology with the ability to track real- time muscle volume and performance in space is crucial. Such technology should: (a) be integrable into a comfortable, lightweight, and unobtrusive form-factor; (b) be able to monitor both large and small muscles; and (c) be reliable and accurate. To this end, we propose RESCUE (REal-time, wearable System for traCking mUscle gEometry), a new class of functionalized garments that utilize multi-mode loops to monitor real-time muscle geometry, a power bio-signal that has been restricted to laboratory settings by a gap in technology. RESCUE brings forward innovations in magnetoinductive waveguides (MIWs), antennas, and algorithms to facilitate the first wearable device with the power to monitor muscle geometry, a bio-signal that has been used to derive key real-time muscle health metrics (muscle volume, force output, fatigue, etc.). RESCUE utilizes a novel multi-mode architecture consisting of conductive loops sewn from e-thread with distinct low- and high-frequency behavior. Lightweight, unobtrusive, and flexible design will empower continuous muscle monitoring. A preliminary investigation into the proposed system has demonstrated the feasibility of each mode of operation, and previous research into muscle geometry as it relates to clinically relevant data has demonstrated the value of the proposed sensor.
Status: Active
Description: Will lead Institute for Model-based Qualification & Certification of Additive Manufacturing (IMQCAM) aiming to improve computer models of 3D-printed – also called additively manufactured – metal parts and expand their utility in spaceflight applications
Status: Active
Description: The integration of plant growth into life support technologies is required to enable long-term human habitation beyond Low Earth Orbit. One of the roadblocks to that goal is being able to reliably produce nutritious food sources for crew. Current plant growth experiments utilize arcillite as substrate despite high mass, high variability, and potential for phytotoxicity. Development of novel synthetic substrates provide the opportunity to control substrate chemical structure and offer optimization of the substrate environment. Hydrogels have historically been used as amendments to improve soil quality for terrestrial agriculture, and evidence suggests that they can be used as the total substrate without negatively impacting plant growth and development. Hydrogels are often more than 99% water by volume and, compared to arcillite, would significantly reduce the payload mass and storage requirements when taking plant growth from experimental to food-supply scales. This project aims to develop granular hydrogel substrates. Polyacrylamide hydrogels of varying monomer and crosslinker concentrations will be created and their physical properties measured, along with polyacrylamide gels doped with modified monomers to increase ion sorption, organic content, and biodegradation. These properties will be used to select candidate gels to use in grow outs of radish (Raphanus sativus), and determine effects of substrate on productivity, nutrition, and development. As a result of this project, a high-fidelity prototype of the proposed technology will have been demonstrated to be operational under controlled environment conditions similar to those found in growth chambers currently available on the International Space Station.
Status: Active
Description: I propose to develop a new type of high-specific impulse (> 2000 s), ultra-high thrust density (> 100 N/m^2) Hall thruster, to enable crewed missions to cislunar space, Mars, and beyond. High power (> 100 kW) electric propulsion (EP) engines with high thrust density are a key enabler for rapid and fuel-efficient deep space travel. The high power translates to thrust levels necessary for moving larger payloads while the high thrust density corresponds to smaller specific mass (kg/kW) and therefore greater acceleration. The conventional wisdom to date has been that magnetoplasmadynamic (MPD) thrusters are the only viable candidate for ultra-high thrust density, high power operation. My aim is to show that it is possible to achieve comparable, if not better, thrust density and efficiency at 100 kW than an MPD with a Hall effect thruster. This will be accomplished by increasing the current density by an order of magnitude over state-of-the art Hall thrusters. If successful, my new version of a high power, high thrust density Hall thruster will offer the advantages of MPD thrusters but with extensive heritage that has already been built around flow and power management for Hall thrusters. As an additional benefit, there are theoretical arguments to suggest that high current density operation may enable efficient operation on alternative propellants like argon, krypton, and even condensable metals. Leveraging these types of propellants may decrease both the cost of the mission and the cost of development testing.
Status: Active
Description: Two-photon polymerization (TPP) is an additive manufacturing technique using femtosecond lasers in the near infrared range to excite initiating species and induce polymerization at the laser's focal point. This method creates nanoscale arbitrary 3D structures with sub-100 nm achievable resolution and the ability to alter the chemical and mechanical material properties. Applications of this technology range from optical devices to tissue engineering and microfluidics. I desire to investigate the application of TPP to space systems. A reliable, repeatable manufacturing method at the established high-speeds could, for example, be utilized for manufacturing crystals or biomaterials in-space, producing nanodevices and sensors leading to spacecraft mass savings, and implementing microneedles in spacesuits for emergency drug delivery. To demonstrate this technology, I propose the additive manufacturing of electrospray emitters, an electric propulsion technology that electrostatically extracts and accelerates ions or droplets to produce thrust. Life-limiting mechanisms of electrosprays involve the propellant flow path at each individual emitter, exhibited through shorting incidences from fluid accumulation at the emitter's base and emission non-uniformities originating in manufacturing difficulties. Achieving greater accuracy in emitter features would mitigate failures and improve performance. To accomplish this, I propose: (i) the numerical simulation of favorable emitter structures, (ii) emitter fabrication in individual and array configurations to demonstrate TPP manufacturing capabilities, and (iii) experimental testing to characterize the resulting electrospray's performance. Validating this technology and producing high accuracy electrospray thrusters could lead to improvements in propulsion on small satellites, like finer pointing accuracy and orbital maneuvering capabilities. Scaling these thruster arrays reveals applications to larger missions, to expand the conduction of space research further into space than ever before. With rapid prototyping capability, repeatedly demonstrated high resolution, and a growing commercial market, two-photon polymerization is a promising technology that could revolutionize electric thruster manufacturing and presents substantial opportunity for space systems applications.
Status: Active
Description: High resolution spectrographs are widely used astronomical tools which finely capture an emitted spectrum of light due to the specific chemical composition of a source object in a technique known as spectroscopy. The 2D projection of the resulting light causes overlapping of subsequent spectral lines and prevents coverage of more than the most prominent features. As a result, these spectrographs are limited to a lower resolution, or fineness of features, at a broad range of wavelengths, or higher resolution at a narrower range of wavelengths. The technological development of the high-resolution spectrograph has been largely stagnant for the past several decades, but this work aims to change the spectroscopic frontier by integrating a radically new device known as a Microwave Kinetic Inductance Detector, or MKID. MKIDs are able to determine the wavelength of each incoming light ray with significantly less instrument noise than other detectors like CCDs. They can operate over a broad range of wavelengths covering ultraviolet, visible, and infrared. MKIDs have undergone rapid improvement since their invention and are currently being used in many applications, most prominent in the MKID Exoplanet Camera (MEC) at the Subaru Telescope on Mauna Kea. I will design and build a brand-new high-resolution multi-object spectrograph (HRMOS) from the ground up and replace the light dispersing component with a tightly packed array of MKIDs, boosting efficacy and simplifying the design. The MKID HRMOS has another promising capability: simultaneously discovering and characterizing faint objects like exoplanets. NASA's plan for the Large Ultraviolet Optical Infrared Surveyor (LUVOIR) would greatly benefit from incorporation of an MKID HRMOS, particular in Signature Science Cases #1 and #2, which together address the characterization and discovery of habitable exoplanets and their biosignatures (atmospheric chemical composition). The research plan will unfurl over the funding period of four years in a series of defined milestones. For most of the first year, the MKID camera will be produced using the latest advancements in MKID technology and the combined system MKID HRMOS will be constructed, undergoing a series of laboratory tests before being declared fully operational. Through the beginning of the second year, I will demonstrate its sorting abilities for distinguishing between light rays of close wavelengths. I will experiment with the MKID HRMOS in various cases to show calibration and subtraction of undesirable effects to establish a record of performance. To finish out the second year, the MKID HRMOS will be tested outside of the laboratory for the first time by capturing the spectrum of the Sun, moving on only when the fine spectral features are resolved. In the third year, I will begin upgrading and replacing components to push the resolution ceiling, measuring system processing speed and abilities to compare to existing state-of-the-art spectrographs, and start capturing the spectrum of a bright, distant star. An even higher goal resolution at this stage will demonstrate that the system is ready for mounting to an existing telescope. In the final year, after successful demonstration of the higher resolution, I plan to collaborate with an observatory to mount the MKID HRMOS to an existing ground-based telescope. I will monitor its performance and test for operability in this relevant environment. This step will extend to the end of the funding period and beyond. With the success at this stage, I will propose building a major instrument intended specifically for a large telescope like the Lick or Keck Observatory based around the understanding and hardware I will develop in this proposal.
Status: Active
Description: The orbital and in situ exploration of the icy moons of Jupiter and Saturn is currently at the forefront of planetary science, with the NASA Europa Clipper mission scheduled for launch in 2024 and the proposed Enceladus Orbilander ranking as the third highest priority Flagship mission in the 2023-2032 Decadal Survey. While the theory for plotting a gravity flyby tour through the satellite systems is well understood and has been implemented, our knowledge about the dynamical evolution of orbits and their uncertainties in the vicinity of these moons is still incomplete. NASA’s planetary protection guidelines, moreover, require that spacecraft avoid biologically contaminating these potentially habitable worlds; a significant challenge for multi-body mission design, where the orbital phase space is dominated by chaotic trajectories. To accurately propagate the state uncertainty of icy-moon mission satellites, a more refined method for nonlinear state estimation is needed. The proposed research seeks to develop a grid-based framework for uncertainty propagation of chaotic space trajectories that utilizes novel orbital element state representations and efficient data structures paired with parallelization for computational feasibility. This work adopts and extends a Grid-based Bayesian Estimation Exploiting Sparsity (GBEES) methodology, which approximates the Fokker-Planck solution, and has been shown to accurately propagate Gaussian uncertainty along the Lorentz attractor. Hitherto, this algorithm has only been used in low-dimensional systems, but will be extended here to treat to the full six-dimensional state that characterizes the space vehicles trajectories. This technique could reveal new options for trajectory design and disposal that, up to now, have been obscured by the complexities introduced by the complicated multi-body environments. This will permit a detailed study of orbital stability in the presence of close encounters and orbital resonances and could feed-forward into Clipper or future icy-moon missions.
Status: Active
Description: In order to support sustainable agricultural operations on Mars it is imperative that Martian surface minerals be augmented in order to support plant life. It has been identified through previous research that the addition of organic matter and removal of salts is necessary for the successful enrichment of Martian regolith. However, there is currently limited technology that enriches Martian surface minerals using plants and microbial activity, despite these life forms being key actors in the formation of soil on Earth. Aeroponics are a likely cultivation method for off-world colonies, with potential capabilities yet unexplored for enriching Martian surface minerals. The space technology proposed is to utilize Martian regolith simulant as a filter for aeroponics in which wheat will be grown. Aeroponics wash organic products from root systems and recirculate nutrients that will constantly inundate the Martian regolith simulant. It is likely that there are several mechanical benefits to using the regolith in aeroponics, such as filtering organic products that would otherwise abrade pumps and clog spray nozzles. It is hypothesized that after the growth of one crop of wheat in aeroponics, the enriched regolith can be removed from the aeroponic system and used as a fertile soil to grow wheat. This space technology corresponds to TABS 7.1.3.17 – biological technology – with the aim to produce a soil product from Martian regolith capable of being used for long term production of food on Mars.
Status: Active
Description: Currently, NASA's life support systems, for CO2 removal, employ packed bed canisters filled with 2-mm-in-diameter zeolite beads (i.e., two beds for H2O and two beds for CO2 removal, making a four-bed CO2 (4BCO2) scrubber assembly). This technology has proven effective, however, there is significant room for improvement. Problems associated with the packed beds are rooted in the random packing of zeolite beads within their given canister. The low packing density, and large void space inherent to a packed bed, create preferred pathways of least resistance for the inflowing cabin air to travel. Thus, causing a maldistribution of the inlet gas across the bed, reducing the volumetric efficiency and CO2 uptake capacity of the packed bed system. For the same reasons, packed beds manage heat poorly. The random packing of beads within a bed reduces the surface contact between individual beads, therefore, resulting in poor thermal conductivity across the spherical beads. Thus, packed beds cannot rapidly disperse heat uniformly, and cause inefficiencies during the regeneration process. Considering the limitations of packed bed systems, replacing zeolite beads with nature-inspired zeolite topologies could improve upon many of the shortcomings that inhibit current systems. Robocasting, a modern direct-ink printing technology, has created the ability to manufacture novel 3D zeolite topologies, with the potential of boosting system performance. Monolithic 3D zeolite designs, inspired by the bronchi arrangement of a human lung can improve (i) CO2 sorption rates and volumetric capacities, (ii) pressure drop penalties across the bed, (iii) heat distribution and thermal transport throughout the bed, and (iv) increase mechanical stability to withstand mechanical shock and vibrations. However, gaps in the fundamental knowledge of both manufacturing and dynamic sorption physics limit the current capacity to optimize geometry and manufacturing techniques.
Status: Active
Description: Space and science instrumentation require electronics that can withstand harsh environments, such as extreme temperatures and ionizing radiation, under the constraints of limited power and mass. We apply new circuit design strategies to overcome harsh environments for mixed-signal building blocks, such as but not limited to data converters and phase-locked loops, where these blocks are an integral part of instrumentation systems. These circuit design strategies are proven in a commercially available CMOS foundry technology that is otherwise not specifically meant for harsh environment operation. The commercial availability combined with harsh environment operation enable cost-effective, highly integrated, and power- and mass-efficient system-on-chip solutions to instrumentation. We are actively working on the following projects. First, a radiation-hard, 8-channel, 15-bit dynamic range, 12-ENOB, 40-MSPS ADC has been fabricated for use in the CERN HL-LHC as part of their readout infrastructure. They require approximately 50k devices and reliable operation across 12 years in a radioactive environment. Currently we are supporting radiation characterization and quality assurance testing of the 50k devices. Second, a 11-bit, 11.5-MSPS ADC has been designed to be operational from -196 °C to +125 °C using forward adaptive body biasing. A prototype has been fabricated and is currently under extensive characterization. Third, to support timing generation using PLL’s, the behavior of voltage-controlled oscillators and phase-locked-loops are being studied down to 4 K.
Status: Active
Description: While we have an increasing number of small-body missions, it has been challenging to deploy a lander that lands on poorly- characterized small bodies, as can be seen in recent failed attempts in the Hayabusa, OSIRIS-REx, and Rosetta missions. Many previous small-body missions, namely OSIRIS-REx and Hayabusa, have utilized rehearsal procedures to minimize the chance of risk; however, these procedures still do not provide the ability to adaptively modify the trajectory in response to gravitational or other uncertainties. In response to this background, the objective of this proposal is to develop an autonomous trajectory adjustment technology with minimum active control for landing and proximity operation about unknown or poorly-characterized small bodies, so that the system has larger adaptability against uncertainties with little reliance on rehearsals. We consider a mothership-daughtership configuration, where the former stays in orbit while the latter land on the small body, and will investigate the theory and methods for the control configuration and algorithms to control the daughtership lander solely from the image from the mothership that deployed it. To determine minimum control, the amount of control necessary to overcome the gravitational uncertainty perturbations will be adaptively optimized based on the error in landing location for the uncontrolled case. The technology proposed as part of this research falls under Technology Area 9.2.8.8: Small Body Proximity Operations. The current TRL of the proposed technology is 2, and this effort aims to raise it to 3.
Status: Active
Description: As human activity on the Moon and Mars looks to surge in the coming years, there is an increasing need among the planetary science community to further understand features of these environments, such as topology and material composition. This work seeks to develop a highly extendable soft robot, called a Vine Robot, that is capable of obtaining geological and contextual information through imaging, proprioceptive sensing, and in-situ sample acquisition over long distances and within confined spaces. This concept looks to expand the capabilities of past and current extraplanetary robotic systems by leveraging compliant material construction and high extension capabilities to explore unstructured treacherous environments on the surface and subsurface of these spatial bodies. Additionally, it will be capable of acquiring and transporting valuable samples for analysis. While Vine robots have been explored for earth-based applications, there are many significant limitations to their capabilities, such as tool attachment, material robustness, actuation, and navigation, that have yet to be explored. The work will focus on developing an innovative soft-rigid hybrid body and end-effector design, modeling non-linear material buckling behavior and control framework, and implementing it into a final functioning system. To complete the proposed objectives, the developmental work will rely heavily on computational modeling, iterative prototyping, and field tests. This effort will open the door for future applications of highly extendable and compliant mechanisms for space exploration.
Status: Active
Description: Spacecraft state uncertainty is a critical challenge due to the unpredictable nature of space dynamics, causing errors to accumulate over time and spacecraft to deviate from planned trajectories. Quantifying and minimizing this uncertainty over time is particularly relevant in cislunar and interplanetary regimes, where complex nonlinear dynamics play a significant role. As these system dynamics cause errors to grow over time and drive a trajectory to deviate from its planned path, corrective guidance algorithms must adaptively re-optimize the spacecraft thrust maneuvers to reach target states and achieve mission goals, such as precise science observations or strict orbit accuracy. To address these challenges, this project proposes combining guidance with efficient uncertainty propagation techniques, resulting in robust chance-constrained guidance that bounds state uncertainty rather than constraining a single deterministic state. State- of-the-art guidance will be advanced by combining stochastic control approaches to uncertainty with nonlinear, non-Gaussian chance constraints while incorporating thrust maneuver errors. This approach offers generality across applications and control methods, improving spacecraft autonomy and scientific returns for space missions in the cislunar region and planetary exploration environments. This research's extension to non-Gaussian chance constraints is better suited for missions with measurement gaps and for future state predictions. By identifying gaps in current guidance laws, incorporating chance constraints with non-Gaussian uncertainty, and applying the novel algorithm to highly dynamical test cases in cislunar and interplanetary regimes, this project accomplishes robust spacecraft guidance under uncertainty. Once formulated for onboard implementation, this algorithm allows for adaptive autonomy for spacecraft in complex dynamics and congested operating environments, which is especially relevant due to increased congestion in near-Earth and cislunar space and the planned utilization of NASA's Gateway as an outpost for new interplanetary missions.
Status: Active
Description: Advances in spacecraft technology have enabled observational satellite constellations containing a greater number of imaging agents, allowing for more complex planetary and climate science missions. However, current methods for constellation operation identify targets and generate multiagent satellite scheduling solutions offline. This paradigm has large ground-based operational overheads since it requires a cycle of (i) data downlink, (ii) target identification, (iii) global task scheduling, and (iv) schedule upload; this results in plans that are brittle to changes to the system, respond sluggishly to an evolving target space, and are computationally expensive and time-consuming to find and uplink, especially as the number of agents increases. These inefficiencies could be mitigated through the introduction of distributed, autonomous tasking. I propose to design and evaluate decentralized satellite autonomy policies for optimization of constellation-wide search-and-image tasks, in which agents collaboratively search for and identify new targets and image them, maximizing the science output of the constellation. The decentralized method has key advantages: As satellites get new information about target locations, they can immediately evaluate which among the set of upcoming targets is best to image or if searching for new targets would better optimize global performance. On a larger scale, this means the constellation will dynamically respond to the evolving target space and be robust to global changes in the network of agents. Overall, this research will increase the responsiveness of terrestrial constellations for environmental monitoring, and it will enable deep-space constellations about bodies with dynamic planetary science environments where communication with offline systems is costly if not impossible.
Status: Active
Description: Electrospray thruster arrays are a promising technology for scalable electric space propulsion with potential for high efficiency and specific impulse. Currently, these arrays consist of a series of microscale sharp structures protruding from a single panel. These structures transport an ionic liquid, which serves as propellant. Inconsistencies in the materials and manufacturing can cause individual tips to fail, resulting in complete array malfunction. To remedy this, emitter tips can be replaced by “pixel” emitters, which would consist of individualized wells embedded in a dielectric material. These wells would be surrounded by a small ring coated with a conductive material to serve as the extractor electrode. Individual extractors would connect to one another through thin, conductive strips, serving as fuses. Upon the shortage of a single emitter, the fuse would disintegrate, allowing the rest of the “pixel” emitters to continue firing, effectively solving the lifetime issue associated with current electrospray thrusters. These “pixels” would function as pixels on an LED screen, where the shortage of a pixel on the screen does not short the entire screen. These arrays would be constructed using masking and lithography techniques and equipment available at the Massachusetts Institute of Technology. A single “pixel,” then a full array, would be manufactured and tested in vacuum chamber facilities at the Space Propulsion Laboratory at MIT using time of flight and thrust tests to measure performance and fuse operation. This proposal would contribute to the advancement of electric in-space propulsion technologies (2.2.1). Using this “pixel” approach, the safety factor of the propulsion systems would greatly improve. Rather than adding significant mass through the addition of multiple back-up thruster arrays, only back-up “pixel” emitters would be added to the system, increasing the robustness, lifetime, and reliability of the propulsion system without significantly increasing its mass, volume, and power requirements.
Status: Active
Description: For further space exploration, NASA hopes to establish a long-term presence on the Moon and Mars. Artemis Base Camp is a planned establishment where astronauts can live and work on the Moon. It will be home to a lunar lodge, where NASA plans to house astronauts for month-long stays to conduct experiments and research. Additionally, the spaceship, Gateway, will be placed in lunar orbit to act as a 'pit-stop' between the Earth and Artemis. Both structures will require flexible manufacturing solutions to support critical life-supporting technologies. Electrohydrodynamic inkjet printing (EHD printing) has tremendous potential to advance In- Space Manufacturing (ISM) and address the need for flexible on-demand fabrication, repair, and recycling capabilities for electronic components in space. I plan to work in a research team in Industrial and Systems Engineering at UW-Madison for the proposed work. Our team has been teaming with NASA to work towards On-Demand Manufacturing of Electronics (ODME). Our goal is to realize thin-film fabrication for the International Space Station (ISS) and other On-orbital Services, Assembly and Manufacturing (OSAM) need. Upon success, we can provide manufacturing capabilities for ISM of all different types of sensors, actuators, and other electronic devices. This will be an essential tool to make sure America can maintain long-term missions and human presence in low earth orbital with a strong commercial market considering sensors/actuators are most likely to be consumables for in-space uses. The research objective is to develop a method to continuously monitor, adjust, and optimize EHD printing parameters autonomously to achieve the necessary quality required of micro and nano scale conductive patterns. This closed-loop, in-situ system can be applied to biomedical, electrical, and aerospace applications of EHD printing, and needs to be created to advance its potential. My central hypothesis is that physic-model-assisted machine learning reduces the prediction time of droplet behavior 10-50 times faster than traditional imaging processing based machine learning algorithms; thus allowing near real-time system monitoring and process control. Three research objectives are: 1) establish a machine learning framework fast and ‘smart’ enough to predict future droplet behavior in EHD printing; 2) create a closed-loop control system to monitor, adjust, and optimize the process parameters in real-time; 3) test quality control of the system in different atmospheric environments. Upon success, EHD printing will allow for sensors, displays, transistors, and optical devices to be manufactured in space, ensuring repair and replacement capabilities, and enabling further space exploration. In addition to the aerospace industry, EHD printing has tremendous potential in the biomedical industry. EHD printing can mimic the microarchitecture of tissues, cartilage, tendons, and blood vessels. EHD printing creates conductive scaffolds that guide specific cellular alignments and have conductive properties that allow for muscle contraction in cardiac tissues. These discoveries tug on personal heartstrings, as they could have helped my mother's heart condition and complications if they were advanced enough. It is my mission to apply the system I develop for EHD printing to conductive tissue engineering as well. I plan to further my breadth of knowledge by pursuing my Ph.D. in advanced manufacturing systems. Through the rigorous study of EHD printing and 3 additional years of being a Lab Instructor, I can confidently step into academia to become a successful professor or NASA research scientist. This experience will allow me to become an accredited public school consultant to enhance STEM education in rural underfunded schools. This NSTGRO fellowship is a remarkable opportunity to further my future research and charity endeavors, and it would enable me to pursue these passions and build a successful future NASA career.
Status: Active
Description: The mysteries of our Earth, life, and future are intricately linked with primitive bodies like asteroids and comets. These celestial bodies are vital targets for exploration as outlined in the 2022 Planetary Decadal Survey. These destinations, however, present unique challenges due to their complex dynamics and the inherent uncertainties of their unpredictable nature. The intricacies of modern and future space missions, encompassing sophisticated technologies such as solar sails, asteroid/comet landings, and deep space rendezvous & docking, necessitate a refined approach to control. The coupled interaction between translational and rotational motion, referred to as 6DOF (six degrees of freedom), is crucial in managing the constraints posed by these mission scenarios. For example, the attitude of a spacecraft during solar sail operations directly impacts thrust direction, and the 6DOF paradigm is exemplified in primitive body landing and rendezvous & docking operations, given the need to balance line-of-sight and glideslope constraints. Moreover, the brevity of the landing phase on a primitive body does not allow for the decoupling of rotational and translational inputs, underscoring the need for a comprehensive 6DOF control framework. Addressing the complexities of 6DOF control in the face of uncertainties posed by a lack of knowledge of primitive bodies and the environment in deep space regions requires a methodology that is both robust and optimal, striking a balance between mission efficacy and cost-effectiveness. This research project aims to develop an innovative 6DOF control framework capable of optimizing maneuvers, thereby reducing mission costs, while simultaneously providing the flexibility necessary to adapt to a variety of space mission scenarios. The proposed 6DOF control framework will ensure safety and optimal maneuverability in the face of uncertainties through robust control techniques. The proposed research focuses on advancing the state-of-the-art of 6DOF control framework, leveraging cutting-edge technologies and methodologies such as Special Euclidean group SE(3) and its Tangent Bundle TSE(3) for 6DOF control, chance-constrained optimization, and machine learning algorithms. TSE(3) provides a geometrically sound approach to handling the combined complexities of attitude and position, while chance-constrained optimization ensures that the spacecraft can navigate uncertainties with a defined level of confidence. The incorporation of machine learning algorithms adds an adaptive layer to the framework, enabling it to learn from the environment and further improve its robustness over time. The proposed 6DOF control framework will directly address the challenges outlined in the Strategic Framework Envisioned Futures by the Space Technology Mission Directorate by ensuring optimal maneuverability under uncertainties, and the research outcome will significantly contribute to the success of NASA's future missions and support its objectives in advancing space technologies. In conclusion, the outcome of this research, a robust and optimal 6DOF control framework, will significantly benefit NASA's future deep-space endeavors. The proposed novel 6DOF control framework will not only reduce the costs associated with complex space missions but will also ensure that these missions are conducted safely and effectively, ultimately unlocking the secrets held by asteroids, comets, and other destinations calling for exploration.
Status: Active
Description: Safety hazards arise from plume-surface interactions (PSI) of rockets on the Moon. A technologic solution for PSI includes in situ derived and constructed lunar bricks (class III construction). However, the strength and thermal assessment of lunar bricks today relies solely on simplified terrestrial simulants. Bricks will be manufactured with varying methods and crystallinity at UTSA using two techniques: (i) melting, pouring and annealing, and (ii) pressing and sintering powdered regolith. The melting method will produce dense bricks that should maximize strength but also requires more energy. The sintering method will typically produce less dense bricks that retain porosity, which reduces their thermal conductivity and the compressive strength, while requiring lower maximum temperatures and less energy. For each method a range of temperature-time histories will be employed to achieve a range of crystallinity. I will rigorously characterize these bricks through optical and electron microscopy, density measurement, differential scanning calorimetry (DSC), uniaxial compression and tensile strength testing, to accurately determine their strength and crystallinity. The ultimate goal is to engineer reproducible, durable, high-strength bricks vital for safety and construction on the Moon. At the core of this proposal is a commitment to pioneer engineering solutions that will make lunar habitation safe and construction more efficient. Currently used regolith simulants are terrestrially-derived and lack crucial, complex, and uncharacterized ingredients like agglutinates, bringing uncertainty to any high-temperature testing and manufacturing in the ISRU context. Currently, the lack of high-temperature data makes it impossible to verify if Earth-made lunar simulants have high-temperature properties that accurately mimic those on the Moon. I will conduct DSC measurements on simulants and on curated lunar samples in the UTSA Heat And Mass Transfer & Experimental Rheology (HAMsTER) lab. After DSC reveals the most thermally analogous terrestrial simulant, manufacturing and testing of bricks will begin. This proposal could be further augmented by an NSTGRO visiting technologist at the Marshall Space Flight Center (MFSC) Plasma Torch Testing Facility (PTTF) which can test the strongest, thermally analogous bricks in simulated repeated rocket take-off and landing. This novel, pragmatic, technology-driven approach will ensure our engineering solutions are faithful to lunar surface materials, and deliver practical and reproducible outcomes furthering space exploration and lunar construction projects. This initiative goes beyond engineering, representing a tangible step toward making sustainable lunar habitation a reality. This proposal directly addresses Space Technology Strategic Framework LIVE: ISRU, and Excavation, Construction, and Outfitting (ECO). Specifically, targeting ECO StarPort Gap ID 1293 In-situ construction of launch/landing pads, as well as addressing the Moon to Mars (M2M) ISRU Objective AS-3LM to characterize accessible lunar resources and data to enable ISRU.
Status: Completed
Description: Satellite-based navigation is a promising solution to provide lunar position, navigation, and timing (PNT) services to support NASA's plans for sustained presence on the Moon. Satellites part of the network providing these services must broadcast their ephemeris as finite parameters in a navigation message to lunar users for user PNT. The proposed innovation is to create a novel framework to generate reliable navigation message parameters for lunar orbiters to broadcast with reduced dependency on lunar ground infrastructure and high Size, Weight, and Power satellite components. The first objective is to generate long-term satellite ephemeris parameters. These parameters will be obtained via stochastic constrained convex optimization, leveraging known parameterization error requirements to find a satisfactory representation of the true satellite state in lunar orbit over a long time interval. The trade- off between long-term navigation data volume, validity interval, and achievable approximation error performance will investigated. The next objective is to harness long-term ephemeris parameters to perform onboard satellite orbit determination and enable onboard generation of real-time and precise ephemeris parameters for navigation message broadcast. Onboard orbit determination will be accomplished by using inter-satellite links to exchange information across the network for collaborative state estimation and timekeeping. Over time, results from orbit determination will correct the long-term navigation parameters, enhancing the precision of the satellite state representation. The performance of this approach will be tested over different lunar constellation configurations employing small satellites to reduce Size, Weight, and Power requirements. The last objective is to determine the feasibility of the innovation from a system-level design perspective. System requirements to implement this innovation within the ever-evolving NASA lunar PNT architectures will be identified. Precise ephemeris parameterization onboard lunar satellites will help reduce orbit and ground infrastructure costs to provide lunar PNT services, alleviating substantial financial burdens of future NASA lunar exploration endeavors.
Status: Active
Description: Long-duration space exploration requires an extensive pharmacy that has the capacity to maintain crew health as well as rapidly respond to unforeseen medical needs. This presents a number of challenges including stability under radiation exposure, infrastructure, space, and cost. Plants are advantageous bioreactors in minimal resource environments due to low contamination risk and scalability, but are crew-time intensive due to maintenance. Kalanchoe laetivirens (Kl), commonly known as “Mother of Thousands,” is a succulent plant capable of asexually reproducing hundreds of clonal progeny called “plantlets” from dense stem cell regions along leaf margins. Agrobacterium-mediated genetic manipulation of leaves can be used for transient expression systems or be inherited in asexually reproduced plantlets, allowing for production of gain-of-function plants expressing recombinant proteins, namely antibodies, secreted peptides, and for vaccine applications. This unique ability allows for rapid response pharmaceutical needs to be addressed through transient expression and anticipated pharmaceuticals to be stored in fresh, actively producing, gain-of-function plants. This system also allows for the long-term establishment and storage of new pharmaceuticals while maintaining independence from Earth. Furthermore, Kalanchoe is highly drought tolerant, making it ideal for indoor vertical farming and requiring no special care. This plant can remain small when given limited space and thrive in a variety of environments, while still efficiently reproducing. This makes Kalanchoe plants compatible with established space-based plant growth systems. I propose to develop Kl into a space optimized pharmaceutical biomanufacturing and storage system to decrease dependence on medication supplied from Earth for prolonged space travel and respond to unforeseen medical needs. To fully exploit the potential of Kl, it is imperative to establish a comprehensive foundation in understanding the genetic basis underlying the potent capacity of asexual reproduction from leaf margins. Efforts towards RNA-sequencing and de novo whole-genome sequencing analysis have garnered insights into transcriptional regulation and the genetic plasticity of Kl as an allotetraploid. Finally, transient expression using reporter genes through Agrobacterium-mediated manipulation of leaves is explored to generate genetically modified next-generation plantlets. These elements provide a framework for genetic control of Kl and to develop methodology towards ensuring the successful and long-term establishment of a space-refined biofactory.
Status: Active
Description: Maybe space is not so silent after all—the inclusion of microphones on NASA's Perseverance Mars rover opens the door to exploring space through sound. Sound is an encoder of the physical interactions that take place between contacting bodies, which provides information that vision cannot. When exploring planetary surfaces, knowing the properties of the terrain is important for selecting an appropriate mobility strategy. The long-term goal of this work is to establish a predictive model of robot sound and to use this predictive model both for inference (e.g. estimating terrain characteristics or detecting robotic and environmental anomalies) and for simulation (e.g. adding sound to commonly-used physics simulators like MuJoCo, Drake, and Gazebo). Being able to estimate the character of the terrain a rover is driving on can support surface navigation and mobility initiatives.
Status: Active
Description: One of the “holy grails” of advanced propulsion engineering is the design of a system with both high specific impulse (ISP) and reasonable thrust levels. Since ISP is a direct function of propellant exit velocity, any high ISP propulsion system must use a physical process that can accelerate propellant particles to very high velocities. Magnetic reconnection (MR) is one such process that occurs throughout our universe in high energy plasmas, yet has not been successfully harnessed for use in a propulsion system. The proposed research will attempt to design and build a propulsion device using torsional magnetic reconnection (TMR) to accelerate plasma propellant. Building on previous research designing a coaxial plasma gun (CPG) and associated pulsed-power architecture, the proposed research will progress in three further primary phases. The first will be to develop a magnetic solenoidal linear null-point architecture to induce TMR in synthesis with the azimuthal field created by the CPG. Secondly, the reconnection/plasma physics of the device will be studied using a variety of plasma/electromagnetic field diagnostics. These will include: high speed visual imagery, high temporal and spatial fidelity B-dot probes to measure electromagnetic fields, triple Langmuir probe measurements, and optical emission spectroscopy using Stark broadening for electron temperature and density, and Mach probes for plasma flow velocity. The final step will be to characterize the device as a propulsion system by calculating operating efficiencies, performing beam diagnostics, and potentially directly measuring thrust. Previous theoretical and numerical studies indicate such a device will be capable of 10,000 – 100,000 s. ISP and ~5 N. thrust with magnetic fields of approximately 0.1-1 T.
Status: Active
Description: This project aims to develop and advance radiation-hardened power electronic and optoelectronic devices capable of operating in extreme environments by studying the impact of operation under high temperature and high radiation on the stability and performance of AlN-based Schottky and p-n diodes. In order to fabricate these devices, conductive n- and p-type AlN must be demonstrated. Using established point defect management methods to manage compensation, highly conductive AlN can be realized via impurity band conduction. Once this is achieved, devices will be fabricated using established methods, such as metal-organic chemical vapor deposition (MOCVD), reactive ion etching (RIE) and photolithography. Devices will be characterized using a high-temperature probing station capable of reaching temperatures up to 1000oC, which allows assessment of device operation under these conditions. Additionally, the effect of high radiation environments will be investigated via radiation dose testing at the Jet Propulsion Laboratory. The fabricated devices will be extensively characterized in order to identify the failure mechanisms, which will then be addressed by modifying device design. In addition to demonstrating conductive n- and p-type AlN, we aim to show kV-class devices capable of operation at temperatures >500oC and under high radiation environments. At the end of this effort, we aim to expand the developed extreme environment capable technology to other device examples, such as solar blind deep-UV APDs.
Status: Active
Description: Thermal protection and flight control are crucial to the success of a planetary entry vehicle. NASA currently utilizes heat-resistant and ablative materials, such as PICA and other carbon-based materials, for thermal protection in high-velocity planetary entries. For planetary entry flight control, NASA typically uses reaction control thrusters, center of gravity shifting with mass ejection, external control surfaces, or a combination of these technologies. However, these heritage technologies will be insufficient for future missions, such as the Mars Sample Return mission, where the entry velocities and peak heat fluxes will be too demanding. Thus, new and innovative technologies are needed to enable and enhance these missions. A novel method of enhancing thermal protection and flight control during planetary entry is by using magnetohydrodynamic (MHD) interaction. During hypersonic flight, a layer of heated, partially ionized plasma exists in front of the vehicle due to a strong bow shock. If a magnetic field is applied to the ionized plasma, the conducting plasma flow experiences a body force known as the Lorentz force. This force increases the shock-standoff distance and, as a result, reduces the convective heat flux experienced. Additionally, the Lorentz force reacts an equal and opposite force that acts as a "plasma drag" and serves as a deceleration mechanism. Typically, flight control is limited in the upper atmosphere of planets because density is too low to produce significant aerodynamic drag. However, the velocity is high enough for sufficient ionization in this upper region, and MHD-induced drag can be utilized for flight control. This MHD-enabled control authority unlocks the ability to fly trajectories with lower heat loads, adding another method of heat flux mitigation. In conjunction with existing and in-development planetary entry technologies, a MHD device would reduce the constraints on current thermal protection systems and flight control mechanisms. Overall, MHD interaction can increase heat flux mitigation, provide a non-mechanical control mechanism, and enhance robustness in uncertain flight conditions. This proposal aims to study the performance of an electromagnetic control mechanism to enhance thermal protection and planetary entry systems. The MHD-induced capabilities can be actively controlled throughout a trajectory by utilizing an electromagnetic device instead of a permanent magnet. The research will experimentally investigate the thermal and aerodynamic performance of a prototype electromagnetic device in a state-of-the-art inductively coupled plasma wind tunnel. The experiments will increase fundamental knowledge of the aerothermal and plasma environment in various planetary atmospheres. Experimental results will be implemented into system performance models and trajectory simulation programs to study the electromagnetic device's system and mission impact. Altogether, this research will provide a prototype electromagnetic control mechanism, ground-based experimentation, and system and mission studies to increase the technology readiness level of MHD control mechanisms. This research will specifically address objectives in TA 9.1 (Aeroassist and Atmospheric Entry) and TA 14.3 (Thermal Protection Systems) in NASA's Technology Roadmaps.
Status: Active
Description: To achieve the desired larger, longer, and farther space missions NASA has planned, an extremely energy dense, intrinsically safe, and locally repairable power system must be designed. Currently, the leading candidate technology to fit this role is nuclear power systems. However, even current state-of-the-art systems fail to meet the key operational requirements that these missions dictate. By switching the material and manufacturing system used in a nuclear reactor, from a classical manufacturing process to one made by additive or advanced manufacturing, we can achieve the repairability needs. Furthermore, advanced manufacturing techniques including additive allows for easier creation of novel metal-composite materials with increased resistance to radiation induced damage thereby increasing the durability of the material and the inherent safety of the built reactor. Recent findings have shown that nanostructured additives (such as carbon nanotubes) in traditionally manufactured metals and alloys can drastically increase radiation resistance at low fraction additions (<2 wt.%), as well as improve mechanical and thermal properties. Our project will build up the local expertise and laboratory capabilities to pursue such novel metal-nanocomposite materials by assessing and using an array of advanced manufacturing techniques. We will perform extensive ion beam irradiation experiments, including single-beam, dual-beam, and in-situ experiments, to determine the effects of carbon nanotubes on a metal’s radiation resistance. We will also utilize advanced machine learning techniques to assist and accelerate the analysis of the characterization data.
Status: Active
Description: This proposal seeks two years of PhD level NSTGRO23 funding under Special Condition 1, given that the author previously received two years of Master’s level funding under NSTGRO21. The objective of this research is to develop a passively actuated, deployable radiator hinge for use onboard CubeSats. Heat will be carried from the CubeSat body to radiator panels for rejection through an Oscillating Heat Pipe (OHP) hinge made of Nitinol tubing. To provide CubeSat thermal management, as the Nitinol hinge increases in temperature, it will passively deploy radiator panels via the Shape Memory Effect (SME) to cool onboard components and then retract to minimize unnecessary heat rejection and the use of survival heating. This system will provide satellites with a dynamic thermal control system that has a high turndown ratio, low weight and cost, increased reliability, and high maximum heat rejection, among other advantages. Based on previous work by the author, this system will have a turndown ratio greater than 6, meeting the goal for variable geometry radiators in TA 14.2.3 “Heat Rejection” of the NASA Technology Roadmap. Previous work with deployable radiator panels are used to inform and accelerate the proposed work herein. However, this work focuses primarily on the deployable thermal hinge as a critical thermal management component. Outcomes include a functional benchtop prototype which allows for simultaneous OHP and SMA operation, a tuned thermal simulation of the system, and the relationship between the temperature of the CubeSat body and the radiator panel deployment angle.
Status: Active
Description: The goal of many in the space industry is to make life interplanetary but there is a gap between where we are now and where we need to be to meet that goal. While there are various technologies currently being pursued to close this gap, nuclear electric propulsion (NEP) and high-power electric propulsion using large solar arrays (SEP) have been presented as viable options. Yet even with their potential advantages, this technology has significant developmental challenges that pose a risk to technological maturity. NEP and SEP require high-power electric propulsion thrusters that must endure high temperatures when operated at such high powers. This heat produced is transmitted through the channel walls and can degrade the thruster operation therefore limiting its performance. Solutions have been explored with the use of heat sink devices and water cooling, yet little research currently exists for cooling the thruster while in flight. In chemical liquid rocket engines, this problem is effectively addressed via regenerative cooling where fluid, usually the fuel, flows through manufactured channels around the outside of the combustion chamber and nozzle. This allows the, usually cryogenic, fuel to cool down the chamber while heating the propellant before it is combusted in the chamber. The overall goal of my research is to develop a regenerative cooling approach that allows the thruster to operate adiabatically and reject all excess heat through propellant pre-conditioning. I propose to do this by first conducting a trade study on various propellants, heat sources in the thruster, cooling channel geometries, and materials. I will then design and simulate a 3D heat model of the thruster, channel geometry, and propellant in ANSYS. Finally, I will leverage additive manufacturing to prototype embedded cooling channels and test the performance with both simulated heat sources and a range of propellants in a vacuum chamber.
Status: Active
Description: This work proposes to use AE for in-situ monitoring of refractory alloy additive manufacturing, with a focus on laser engineered net shaping (LENS), a type of laser directed energy deposition (LDED) process. While AE signals are being collected during printing of refractory alloy components, pores and cracking will be intentionally introduced. The melt pool will be monitored via optical tomography. To confirm the size and location of defects, completed parts will be inspected via XCT and then sectioned for optical microscopy. I will leverage machine learning (ML) to examine the relationships between features extracted from AE signals and ground truth data that characterizes defects to develop an ML model that can be applied in real time. The new model will use only the acoustic emission signals as input to allow for in-situ monitoring. Using both in-situ (optical tomography) and ex-situ (XCT and optical microscopy) ground truth data will combat the high false-positive rate of defect detection that is a common challenge of AE monitoring by considering the possibility of defect healing on subsequent passes. The proposed work responds to TA12.4.2.2: Model- Based Operations and TA12.4.2.3: Additive Manufacturing by integrating smart sensors and analysis and decision tools into the LDED process. Refractory alloys are used in propulsion structures, leading edge materials, reactor fuels for nuclear thermal propulsion, and in other high-temperature in-space structures. Thus, the proposed work also aligns directly with TA12.1.4.2 High/Ultra-High Temperature Material Technology Candidate.
Status: Active
Description: Electrospray thrusters are a subset of electric propulsion (EP) systems that use conductive ionic liquids as propellants and electrostatically accelerate ions from a sharp emitter tip to form a plume. The ionic liquid propellants are composed of complex organic cations and anions which have much different chemical composition and properties compared to the typical noble gas electric propulsion propellants. Because these ionic liquid propellants are novel in use and have unique chemical properties (e.g. condensable in vacuum), there is a need for researchers to understand the interactions of their plumes with surfaces. While noble gas ion-surface interactions have decades of research due their nearly ubiquitous use among EP systems, the surface interactions of complex ions are hypothesized to be much different. For example, they may deposit at low energies, or form new product ions at high energies. Both experiments and simulation indicate that particles from the plume impact thruster and spacecraft surfaces like the extractor electrode, resulting in propellant accumulation and eventual device failure. However, there is a wide gap in the knowledge of the fundamental physics of these molecular ion-surface collisions at the nanoscale and how they ultimately impact thruster lifetime and performance. In conjunction with Advanced Space Transit and Architectures Lab (ASTRALab) at Cornell University, I will characterize ionic liquid ion-surface interactions for the range of conditions relevant to thruster operation. I will first conduct molecular dynamics simulations involving discrete particles to predict collision products as a function of ion type, surface characteristics, and impact energy. These results will provide insight into impact products and will inform ion-beam collision experiments. Next, I will develop secondary ion mass spectrometry as a novel diagnostic technique for electrospray systems to study collision products. Finally, I will leverage complimentary diagnostics to assess the time-integrated effects of collisions on surfaces. My work will characterize the secondary emission of electrospray plume impacts with spacecraft surfaces and establish secondary ion mass spectrometry as an electrospray diagnostic, thus actively contributing to the raising of the TRL of electrospray systems.
Status: Active
Description: Oxygen is an essential component of critical space technologies such as spacecraft propulsion, life support (e.g., water and breathable air), and power systems. NASA has therefore identified oxygen as a primary target for In Situ Resource Utilization (ISRU), as extraterrestrial sourcing of oxygen would significantly reduce Earth launch mass requirements and greatly simplify mission planning for lunar missions and beyond. This would not only result in more effective missions but cheaper ones as well. This proposal has the ultimate objective of designing a demo reactor to extract oxygen from simulated lunar regolith at a rate suitable to meet NASA's needs, with the stretch goal of building the reactor and validating it. A testbed reactor will be built that leverages a microwave-powered hydrogen surface-wave plasma source to produce reactive chemical species that will strip the oxygen from lunar regolith simulant. Surface-wave plasmas are particularly effective at producing reactive species and will thus enhance the reactor's oxygen extraction capability compared to other extraction techniques. Previously developed physics-based models will be adapted and improved to model the oxygen extraction from lunar regolith using such hydrogen plasmas. Oxygen removal experiments utilizing the testbed reactor will be leveraged to validate the results of the improved models, using optical emission spectroscopy, Langmuir probes, radical probes, and X-ray diffraction. Finally, the validated physics-based models will be used to design and predict the performance of the oxygen extracting demo reactor to ensure it meets NASA's needs. The demo reactor will operate at significantly colder temperatures than other leading competing technologies whilst performing at a higher level. It will enable the future ISRU capability of routine oxygen extraction from extraterrestrial bodies which will dramatically decrease mission costs and complexity.
Status: Active
Description: Lithium-ion batteries (LIBs) are essential components of space travel, and they enable fundamental technologies such as space suits, satellite probes, rovers, drones, and handheld equipment. Commercial LIBs are typically operated between 15 degrees Celsius and 35 degrees Celsius, above which accelerated electrolyte decomposition and SEI growth occur, and below which sluggish reaction kinetics cause lithium plating leading to irreversible capacity fade and dendrite growth. To better utilize LIBs for crewed missions to the lunar surface and Mars’ moons, which experience temperatures well outside of these standard bounds of operation, it is necessary to characterize the surface reactivity and interfacial kinetics at the solid electrode/electrolyte interface (SEI) layer for more extreme temperatures. This research proposes to characterize the charge-transfer kinetics at the SEI, and the performance benefit of co-modified systems containing fluorinated electrolytes and preferentially-stable electrode coatings in LIBs tested over a wide temperature range of -60 degrees Celsius to 100 degrees Celsius. This will be accomplished using a three phase study, starting with the characterization of low temperature rate-limiting desolvation reactions, as well as the high temperature reactivity between the test electrolytes and their SEI layers, in order to better understand their mechanisms and how to mitigate them. Second, independent electrochemical analyses coupled with advanced materials characterization techniques will be utilized to explore the capability of artificial coatings to prevent surface reactivity, transition metal dissolution, and the formation of unfavorable SEI chemistries. Finally, these independent SEI mitigation techniques will be translated to LIB full cells for analysis of coupled modified-electrolyte and preferentially-stable coated-electrode systems. This research will help answer the fundamental knowledge gap concerning the degradation mechanisms during SEI formation, and simultaneously develop novel battery configurations that better enable NASA’s missions exploring the solar system and galaxy.
Status: Active
Description: Resource and “raw” material acquisition for in situ resource utilization (ISRU) on planetary surfaces is challenging due to the extreme environments (low gravity, thin or no atmosphere, and abrasive dusty regolith). Due to the inherent challenges of ISRU and infrastructure development on planetary surfaces, excavation processes (the most common method of gathering bulk materials for resource extraction) must be optimized in terms of time, energy, and safety. The central objectives of this proposal are to develop quantitative experimental and computational capabilities to increase the efficiency and reduce risk involved with regolith excavations for ISRU material acquisition and planetary infrastructure development. Addressing the problems facing extraterrestrial regolith excavation requires quantification and prediction of excavation forces as a function of regolith properties (e.g., particle size distribution and mineralogy), proper scoop designs, and the use of methods to reduce the forces required to excavate material. Proposed methods to model and optimize the efficiency and safety of planetary regolith excavation involve the development of experimental hardware to test excavation tools and use the collected data to calibrate and verify computational models of planetary excavation. This proposal is directly in line with the objectives of the 2023 NASA Space Technology Graduate Research Opportunity (NSTGRO) and NASA in general. The NSTGRO objectives are to develop space technology as well as train researchers in space technology development, and this work provides relevant technologies that directly enhance the efficiency and safety of surface operations through research performed by a graduate student in close collaboration with NASA researchers. NASA’s goals of settling humans on extraterrestrial bodies are fundamentally driven by the ability to safely, reliably, and sustainably interact with planetary surfaces to acquire and local resources; the proposed research will address these needs and enhance NASA’s capabilities in space technology development and solar system exploration.
Status: Active
Description: The use of fully autonomous systems is necessary in situations where human intervention is impractical, too slow, or too tedious. For instance, a rover on Mars must explore autonomously since communication delays prohibit human teleoperation. Similarly, a free-flying robot aboard Gateway should autonomously perform routine inspections while the space station is left unattended. Achieving precise and efficient control of these systems is essential to ensure high-performance task execution while minimizing resource consumption. Controllers are designed to optimize performance based on established system designs and operating conditions. However, performance may deteriorate unexpectedly due to modelling errors, changing dynamics, or inadequate simulation or testing environments. For example, a quadrupedal robot initially ground tested on Earth might encounter unexpected terrain challenges on the Moon. Similarly, a free-flying robot may undergo wear and tear that impacts its actuation dynamics. Hence, it is crucial for these systems to autonomously adapt to varying or unmodeled conditions. The goal of this work is to develop algorithms for robotic systems which learn from past experiences to adapt to changing dynamics and environments that are difficult to simulate. Methods will be devised to learn unmodeled dynamics and physics-based models will be leveraged to accelerate learning. Learned components will be used to fine-tune control policies for robotic systems operating in complex, high-dimensional environments. Emphasis will be placed on conducting experiments with real-world hardware to validate the effectiveness of the algorithms developed through this work.
Status: Active
Description: All future NASA missions require reliable power generation capabilities. However, there are many missions that cannot rely on the conventional solar cell or battery technologies because of extended duration, distance from the sun, or harsh conditions. Radioisotope thermoelectric generators (RTGs) offer a consistent power supply regardless of solar irradiance and independent of exterior conditions. RTGs consist of a radioactive heat source surrounded by thermoelectric n and p type couples. These couples convert the heat into usable power without any moving parts or possible wear. The power output of an RTG is governed by two factors: the amount of heat that the heat source can generate and the efficiency the thermoelectric n and p type materials. High temperature thermoelectrics are needed to enable high temperature heat sources, but these materials often have poor thermoelectric properties at low temperatures. Grain boundaries have been shown to severely impair the electrical conductivity of thermoelectric materials at low temperatures paired with smaller reductions at high temperature. By removing or controlling the grain boundaries in high temperature thermoelectric materials, their conductivity and hence efficiency can be greatly improved, resulting in higher power outputs for RTGs. This proposed research plans to analyze and exploit the influence of grain boundaries on the thermal and electrical conductivity of the high temperature thermoelectric materials Yb14MnSb11 and La3Te4 to boost RTG efficiency. Recent work on the thermoelectric material Mg2Sb3 has shown a more than two-fold improvement in thermoelectric figure of merit at low temperatures while still improving high temperature properties through grain boundary engineering and the tailoring of processing conditions. This approach will be applied to these high temperature RTG materials in conjunction with long term stability testing to ensure reliable performance in typical RTG operating conditions.
Status: Active
Description: Many emerging technologies demand power converters with smaller form factors and lower cost. Most efficient power converter designs rely on magnetic components (inductors or transformers) which often dominate the size, losses, and cost. Monolithically fabricated on-chip magnetic components have the potential to replace traditional wire-wound components to enable dense (in volume and mass), high-frequency power converters with low production cost and high reliability. This benefits existing power converters and enables new, highly-granular architectures. Fabricating these components has faced a difficult tradeoff -- materials that are easy and inexpensive to deposit are less suitable to the very high operating frequencies (tens of megahertz (MHz)) needed for miniaturization to chip-scale size, while materials that are suitable to such high frequencies have been slower and more expensive to deposit. This research aims to lessen or eliminate this tradeoff by: (1) developing a high-rate, large-area deposition process for a promising magnetic material CoZrO and (2) characterizing and optimizing the proposed material for power conversion.To accomplish these objectives, we will optimize both the process and material based on a physics-based model of the material and characterization of real samples. The proposed research will provide a faster and reliable method for manufacturing on-chip magnetic components, enabling the miniaturization of magnetic components and power converters. The integration of magnetics and entire power converters on-chip supports NASA's interests in creating more decentralized and less massive power distribution systems.
Status: Active
Description: This proposal plans to investigate the mechanisms behind pole erosion in Hall thrusters. Hall thrusters are an efficient alternative to chemical propulsion for in-space missions. However, to make Hall thrusters an even more competitive alternative, their lifetime must improve. Magnetically shielded Hall thrusters have the longest lifetime among Hall thrusters, but magnetically shielded Hall thrusters are susceptible to erosion of the magnetic poles. However, current simulations are not able to predict the observed levels of pole erosion. The challenge in predicting pole erosion is that the ions that erode the poles are anomalously heated before striking the poles. It is believed that the ions are heated by plasma instabilities near the poles, specifically by lower-hybrid instabilities. I plan to experimentally verify the presence of these instabilities and to improve our understanding of these instabilities. Because of the millimeter length scale of these instabilities, typical plasma diagnostics are not capable of detecting them. I propose to develop a coherent Thomson scattering diagnostic, a type of laser plasma diagnostic, to detect and characterize lower-hybrid instabilities near the poles of a magnetically shielded Hall thruster. While instabilities can often be simplified to propagate in only one or two dimensions, I plan to use coherent Thomson scattering to characterize the three-dimensional structure of these instabilities. With the measurements I provide, kinetic simulations will be able to produce an accurate model of the ion heating due to the lower-hybrid instabilities near the magnetic poles. This could potentially result in accurate pole erosion simulations, which would then be used to optimize magnetically shielded Hall thrusters to minimize pole erosion. As a result, the proposed research can have a direct impact on increasing the lifetime of Hall thrusters. This would allow Hall thrusters to support a wider range of NASA missions, including future human missions to Mars.
Status: Active
Description: Linear Covariance Analysis (LCA) is a computationally efficient method for uncertainty quantification that yields direct statistical information about a nonlinear trajectory. LCA performs three orders of magnitude faster than the current method for uncertainty quantification, Monte Carlo Analysis (MCA), and yields direct statistical measures of uncertainty. Currently, uncertainty can only be propagated about a single reference trajectory in LCA, LCA can only model Gaussian noise, and LCA can only be applied to sufficiently linear systems. However, guidance algorithms like hazard avoidance with large diverts result in multiple nonlinear nominal trajectories that branch from the initial trajectory, each with their own uncertainty. By advancing the field of LCA to enable efficient, accurate UQ, the applicability of LCA will increase for mission design of intelligent autonomous systems; guidance, navigation, and control (GNC) analysis; and onboard navigation. To accomplish this goal, the limitations introduced above will be addressed. With the goal of integrating automatic trajectory branching into LCA, first, MCA will be used to find the branch point to use in LCA. Then, new method for representing uncertainty in LCA will be developed from statistical methods like Gaussian mixture models (GMMs), which can represent the uncertainty distributions at the branch point. GMMs can also be used to represent non-Gaussian distributions (i.e. uniform), which are useful for UQ of many autonomous systems. Third, Unscented Kalman filter theory will be applied to LCA to develop a method for autonomously predicting the location of a branch point or a recombination point. Fourth, the Koopman operator (KO) will be used to model nonlinear systems as high-dimensional linear systems, which can increase the accuracy of LCA. Note that these tasks will not be completed in series, but rather in parallel. Simultaneously, effort will be made to augment the computational efficiency of LCA by using autodifferention and computer algebra. Through these efforts, a single LCA simulation can be used to capture the uncertainty of a complex nonlinear multi-branched trajectory, representing a wide variety of NASA missions, from docking operations, to crater avoidance on Lunar landing, to obstacle avoidance for missions on Earth. This work will aid NASA mission design for many complex intelligent autonomous systems, such as human-class Martian vehicles, lunar landers, and planetary aircraft. LCA can be applied to both the mission planning phase, as a method for rapid trajectory analysis, and to the operational phase, as an onboard GNC scheme, for these and other missions. Onboard, robust, accurate UQ will be invaluable to increasing autonomy for many proposed and current missions, like Artemis, Mars Sample Return, and Dragonfly.
Status: Completed
Description: <p>Multimode micropropulsion (MM) is the use of two or more distinct types of propulsion in a single device, and is a promising technology for addressing the needs of CubeSats and other microsatellites. MM thrusters typically combine a high thrust mode (usually chemical) and high specific impulse mode (usually electric) into a single propulsion device. MM can enable new missions for microsatellites, offers improved mission flexibility, and allows for more efficient trajectories than traditional propulsion concepts under some circumstances. While the benefits of MM are well established, adverse interactions between the different modes in multimode microthrusters have not been studied in detail, and may result in difficulties when integrating the two modes into a MM device. In the proposed research, the interactions between the chemical and electric modes in a combined chemical microtube and electrospray microthruster will be investigated. Key questions about how the modes interact have been identified, and a detailed research plan has been developed to address them. One example of a potential adverse interaction is secondary chemical reactions after the chemical mode is stopped that may impede subsequent operation of the electrospray mode. This study would be the first of its kind to investigate mode interactions in MM, and will serve to increase confidence in the MM concept and to inform the design of a practical multimode microthruster.</p>
Status: Completed
Description: U.S. Space Exploration Policy specifies the critical importance of establishing an outpost on the Moon to provide the foundation for human missions beyond cislunar space. However, launching every spare part and system required for long-duration deep space missions is cost prohibitive. To improve safety and reduce risk/cost, the key to any sustainable presence in space is the ability to utilize in situ resources for onsite manufacture and replacement of consumables on demand. Maximum launch mass advantage will be achieved when in situ materials are used. Thus, a development essential to sustained Lunar occupancy is the capability to extract metals, oxygen, and water from regolith. Molten oxide electrolysis (MOE) has previously been studied for regolith resource extraction but requires temperatures between 1400°C and 2000°C. High energy input requirements, safety concerns, and material compatibility problems result. An alternative to MOE leverages acidic ionic liquids (ILs): organic salts which are molten at room temperature and whose properties, such as species solubility, are determined by their tunable molecular structure. Properly designed ILs can dissolve the highly stable metal oxides that compose Lunar regolith at temperatures below 200°C. The solution can be processed electrochemically to claim metals and oxygen. This low TRL, regenerable process has been demonstrated in the laboratory for Fe2O3. However, current IL/acid combinations cannot fully dissolve titanium and aluminum oxides or even partially dissolve silicon oxides. More work is also required to refine the electrochemical process for recovery of high purity, single element, metal feedstock. This proposed research will develop a breadboard electrochemical process that uses target-metal electrodes and acidic ILs to selectively extract high purity, single element metals from regolith simulant. Additionally, computational chemistry and experimentation will be used to identify task specific ILs with functional groups targeted at improved performance dissolving titanium, aluminum, and silicon oxides.
Status: Completed
Description: <p>The goal of this NSRTF Proposal is to design, build and test a magnetometer instrumentation package for space while decreasing volume, mass and power needs. The instrument will consist of a miniaturized optical magnetometer designed to take scalar and vector measurements, an attitude determination system, and an optical bench that will serve as the integration platform for the instrument. An optical magnetometer utilizes the effect that magnetic fields have on the precession rate of the magnetic spin of atoms to accurately and precisely measure the magnetic field present. Furthermore, an attitude determination system provides precise knowledge of the orientation of the magnetic field. In order to achieve this goal, the proposed project includes the adaptation of an existing miniaturized optical magnetometer to have vector measuring capabilities. This adaptation will include mechanical changes, as mutually orthogonal coils will need to be added, as well as changes in the electronics and software of the system to accommodate the additional information that the instrument will provide. The system will be built and tested for accuracy, precision, reliability and the ability to survive in space. Considerations to take into account for any instrument to survive in space include: radiation tolerance, resistance to temperature changes and the capability to survive the vibrations experienced during launch. The instrument's packaging will be designed such that it can contain the magnetometer and an off-the-shelf attitude determination system from Blue Canyon Technologies while maintaining alignment. Precise alignment of the two subsystems allows the vector components of the magnetic field to be accurately determined. Alignment biases and errors will be calibrated during testing. The optical bench will be designed to avoid expansion, contraction or warping due to any of the conditions of space, the most hazardous being temperature variations. In the optical bench mechanical design the material chosen must be resistant to temperature changes and must be non-conductive to avoid the introduction of external magnetic fields to the magnetometer's measurement. During the design process, mechanical, thermal, and dynamics models will be built to meet the different specifications described above; these models will then be compared to the results of testing. This instrument will be built at the University of Colorado Boulder, utilizing the facilities available in the Aerospace Engineering Science department. Performance and environmental tests will ensure that all specifications are met. Testing facilities will include a thermal vacuum chamber, a vibration table, and a magnetic shielding enclosure for noise characterization. An alignment test apparatus will be designed during the development of the instrument. This proposal will further the capabilities of space magnetometers and allow them to be used in smaller satellites including CubeSats, without compromising the precision and accuracy of the measurements. As the NASA Space Technology Mission Directorate, and this solicitation specifically, aims to further develop field and particle detectors such as magnetometers, the proposed project will further NASA's technological objectives. This magnetometer instrument will further address the scientific objectives of NASA with the ability to obtain data relevant to planetary and heliophysics science.</p>
Status: Completed
Description: <p>Exploration of the outer solar system, starting with the early Pioneer probes, has given humankind a glimpse into the nature of the gas and ice giants. The moons of Jupiter have transformed from Galilean sketches into entire worlds that we can observe and physically understand, giving great insight into our own planet and the formation of the solar system. However, despite all the observations we have collected, there are still far more secrets to uncover. Measurements of the outer planetary environments are much more difficult to obtain due to the expense of sending a spacecraft to investigate and, as such, we have a very limited capability to resolve phenomena spatially and temporally. Using this technique with small spacecraft like CubeSats rather than large, monolithic spacecraft in the outer planets would greatly enhance understanding of their environments, while decreasing mission costs. Compounding the lack of data are the harsh environments surrounding the outer planets. Even in Earth's orbit, dangers from solar and cosmic radiation, space plasmas, space debris, and meteoroids have contributed to numerous mission failures over the years. These hazards, though destructive, present an omnipresent energy source in the space environment. Rather than succumbing to this danger, an opportunity exists to harness these resources. The goal of this research is to develop a Space Environmental Electrical Power Subsystem (SEEPS) by: characterizing the most promising alternative power sources applicable to deep space distributed sensing and long term interstellar missions; design prototype SEEPS hardware to harvest this energy effectively; validate, optimize, and iterate on these designs through simulation and experiment; and begin design work on a SEEPS module for a CubeSat.</p>
Status: Completed
Description: Efficient communications systems and effective computing techniques are crucial to ensure the success of each NASA mission. Considering the disrupted and wireless nature, efficient space communications require the improved automation, environment-awareness, and intelligence. To meet this requirement, this project intends to develop a resilient networking and computing paradigm (RNCP) that consists of two essential parts: (1) a secure and decentralized computing infrastructure and (2) a data-driven cognitive networking management architecture. Furthermore, we will evaluate the performance of our proposed RNCP in various space communication environments.
Status: Completed
Description: <p>While great strides in cosmology have been made in the past decades, the cosmological picture is incomplete without an understanding of the mechanism of inflation and the nature of dark energy. The Cosmic Microwave Background (CMB) contains slight anisotropies in its temperature and polarization spectra that can be used to probe the mysteries of inflation and dark energy. However, the anisotropies in the CMB spectrum are very faint, making their measurement a technological challenge. Recent advances in detector technologies have ushered in an era in which cosmological parameters can be measured precisely from the CMB anisotropy spectra. However, the faint polarization signal in the CMB that holds information about inflation has yet to be detected. This proposal is for work on designing, testing, and fielding new, multi-frequency polarization detectors that will be deployed in large format focal plane arrays in the polarization receiver of the Atacama Cosmology Telescope (ACTPol) and an extension of the Atacama B-mode Search (ABS). These detectors will further enhance the sensitivity of measurements by adding multiple frequency bands of observation, which will allow for the improved removal of contamination to the signal from the Galaxy. Through ground-based observations, the new detectors will further constrain inflation by seeking to measure the inflationary polarization signal while serving as a testbed for future NASA inflationary probe satellite missions. This fellowship would allow me to contribute to the technological development and field-testing of new detectors that would aid NASA in reaching its scientific objectives while building the necessary expertise to be involved in future NASA missions.</p>
Status: Completed
Description: <p>The future of Mars exploration will require landing vehicles much larger than anything humans have ever attempted. This challengedrives a need for a new entry and descent technique: Supersonic Retropropulsion (SRP), the use of firing rockets to reduce speedwhile still in the upper atmosphere. Due to the difficulty to test Mars SRP systems on Earth, NASA is relying on computational (CFD)simulations to help motivate design decisions for future entry and descent vehicles. A large multi-center team at NASA has spentthe better part of the last decade developing cutting edge CFD simulations of SRP flow fields. While many significant findings haveresulted from the studies, the results have exposed many gaps in current turbulence modeling techniques that will need to be addressedbefore results can be used to design full-scale SRP vehicles.This project proposes to innovate and expand on modern CFD techniques to model high energy flow structures. The existingcomputational tools implemented by NASA and industry are based on solvers that were never intended to handle the highlycompressible flows found in SRP systems. Due to this, most published SRP solutions show high uncertainties or inconclusive resultsin the highly turbulent regions. We plan to bridge modern high energy physics capturing techniques only conceptualized in academiawith current NASA solvers in a way that increases the confidence in CFD solutions of SRP flow fields so that they can be a valuable,reliable design tool for future Mars vehicle design.Ultimately, our project will benefit NASA and the high-speed flow community as a whole by developing and applying novel techniquesto SRP flow problems. In doing so, we will achieve physically accurate data to aid in vehicle design for NASA, but also generatevaluable data-sets for the high-speed flow research community.</p>
Status: Completed
Description: I propose an experiment to study two-phase flow boiling in microgravity. Obtaining a fundamental understanding of the nature of flow boiling fluid mechanics and heat transfer in space environments will allow more compact and efficient heat exchangers to be used in space. The experiment will be conducted using high-speed CCD cameras to record HFE 7100 flowing through a transparent sapphire tube test section. The inner wall of the tube will be lined with a transparent conducting polymer film that can be electrically heated. Quantum dots will be dispersed along the bottom half of the polymer film. Quantum dots fluoresce when excited with blue or UV light, and the intensity of their emission decreases with increasing temperature. The goal of this experiment is to track the intensity changes of the quantum dots with the CCD cameras in order to obtain a temperature distribution along the inner wall of the test section while the polymer film is heating the fluid. This temperature data can be used to obtain values for local heat transfer for the test section. Ground-based experiments will be tested first in order to confirm the validity of this method with respect to current flow-boiling correlations. The experiment apparatus will be optimized by mass and volume in order to increase feasibility of being able to run on either a parabolic flight or the International Space Station. Performing the temperature acquisition in either of these environments will allow correlations to be made for flow-boiling in microgravity environments. The resulting data from this experiment will help develop more accurate correlations for space-based heat exchangers, allowing spacecraft to distribute heat and power more consistently.
Status: Completed
Description: In a space habitat, air revitalization is a necessary function for maintaining a safe and breathable atmosphere for humans. This functionality includes removing carbon dioxide (CO2) and trace contaminants (TCs), providing oxygen (O2) and nitrogen (N2) makeup gases, and controlling the humidity. In an open-loop environmental control and life support system (ECLSS), CO2 and TCs are vented out of the space habitat, while O2 and N2 are supplied by regular resupply missions. For long duration missions, closing the ECLSS consumables loop has potential to reduce the costs associated with resupply missions by decreasing their frequency and the consumable mass they are required to bring. For future missions with target destinations of asteroids, the moon, and Mars, consumable resupply missions would be logistically difficult, if not impossible. As such, recycling all materials on-board a spacecraft becomes a critical, mission enabling functionality. With respect to air revitalization, consumable recycling largely amounts to reducing CO2 to yield O2. This same process may also be useful for in-situ resource utilization (ISRU) on Mars by reducing atmospheric CO2 to supply a habitat with O2 and propellant. This research proposes to investigate the direct generation of O2 via the reduction of CO2 in an electrochemical cell utilizing an ionic liquid (IL) catalyst. The current method to reduce CO2 aboard the space station is the Sabatier process. This process reacts hydrogen with CO2 at high temperature and pressure to produce methane and water. In order to get O2 from the reduced CO2, the water produced from the Sabatier process is electrolyzed, splitting it into hydrogen and oxygen. Currently, there is no implemented system that utilizes methane space station so this resource is vented to space, resulting in a loss of both carbon and hydrogen. Disadvantages of this current state of the art for CO2 reduction and O2 generation in a spacecraft are requirements for high temperature, pressure, and power usage with a significant amount of system complexity to support the processes. Electrochemically reducing CO2 is normally a very energy intensive process. However, ILs have properties that let them act as both CO2 absorbers and reduction catalysts, effectively decreasing the required energy to recycle CO2. By enabling reduction of CO2 directly to the products of O2 and carbon monoxide (CO), this process eliminates the need to provide hydrogen as feedstock and the need for a separate water electrolysis system to split water into hydrogen and oxygen. Because there are a vast number of potential cation-anion pairs that can be made to form ILs, and because ILs can be expensive and difficult to synthesize, a means of predicting IL properties prior to synthesis would be extremely valuable. This research aims to investigate the properties of ILs based modeling the molecular structure of their cation-anion pairs. ILs that are determined to have favorable properties to CO2 reduction and O2 generation will be studied with respect to their intrinsic properties, as well as their operation through a range of environmental conditions. Improving efficiency and scalability of this electrocatalytic reduction via IL selection and electrochemical cell design are the ultimate goals of this research. While this work will advance technology that can improve upon the current state of the art for CO2 reduction and O2 generation in a spacecraft, it can also be prove beneficial to the energy production industry and to the environment. If electrocatalytic reduction of CO2 can become commercially viable, it will create a new avenue for producing renewable energy and it has the potential to reduce the impact of energy production on the environment.
Status: Completed
Description: <p>The Center for the Utilization of Biological Engineering in Space (CUBES) will leverage partnerships between NASA, other federal agencies, industry, and academia to: 1. Support biomanufacturing for deep space exploration; 2. Advance the practicality of an integrated, multi-function, multi-organism biomanufacturing system on a Mars mission; and 3. Showcase a continuous and semiautonomous biomanufacturing of fuel, materials, pharmaceuticals, and food in Mars-like conditions. NASA’s 2015 Journey to Mars document describes the next pioneering steps in space exploration through three tiers of missions: Earth Reliant, Proving Ground, and Earth Independent. CUBES will be strategically aligned with all three tiers. A CUBES demonstration biosystem will baseline future Earth Reliant testing in 3D-printing, in situ resource utilization, and food and pharmaceutical production. CUBES research could help minimize resupply needs on a Proving Ground mission. Finally, use of the CUBES-produced biosystem to harvest Martian resources for fuel, water, oxygen, and building materials will satisfy requirements for Earth Independence. CUBES will be organized into four divisions to achieve this planned showcase. The requisite systems design and engineering efforts to optimally allocate and utilize Mars resources, tightly integrate and automate internal processes, and satisfactorily achieve biological and mechanical performance according to mission specifications will be the domain of the Systems Design and Integration Division (SDID). Activities to harness in situ resources, decontaminate and enrich regolith, and transform human and mission wastes to media and feedstocks for utilization by downstream processes will be the responsibility of the Microbial Media and Feedstocks Division (MMFD). The manufacture of propellants, biopolymers and useful chemicals from MMFD media and feedstocks along with the recycling of manufactured products at the end of their serviceable life will be tasked to the Biofuel and Biomaterial Manufacturing Division (BBMD). A key component of the BBMD-SDID interface will be the use of generated biopolymers in additive manufacturing (3D-printing). Plant and microbial engineering to realize food and pharmaceuticals for astronauts along with the recycling of plant wastes will be the focus of the Food and Pharmaceutical Synthesis Division (FPSD). The primary CUBES research objectives are: 1. In situ microbial media production, which harnesses Mars atmospheric and regolith resources for downstream biological use; 2. In situ manufacture of mission products, which creates outputs like propellants and building materials that are fundamental enablers of any long-duration space mission; 3. In situ food and pharmaceutical synthesis, which allows these long-duration space missions to be manned, and uses plants and microbes that provide food, nutrients and medicine; and 4. Space and complex systems engineering, which analyzes, guides, tests, improves, and integrates the internal processes of objectives 1-3 above. The CUBES goal of efficiently using in situ resources and effectively recycling them to drive the manufacture of useful products will meet a long-standing need for space missions, which is to substantially reduce manufacturing-infrastructure mass and related costs in harsh conditions. The planned CUBES output of a semi-closed loop that integrates resource-recovery in a resource-poor environment with waste streams to biologically drive the manufacture of fuel, materials, pharmaceuticals, and food will establish the capacity to biologically support manned space exploration on par with abiotic techniques. CUBES benefits will include: 1. Engineered microbes to convert limited or marginally accessible Martian feedstocks, such as atmospheric gases at low partial pressure and nutrients from contaminated/toxic land, into valuable commodities. 2. Novel biologically-coupled nanotechnologies to fix available carbon and nitrogen and to transfer energy into biosynthetic processes; 3. Refined plants and plant microbiomes that grow in restricted space, light, water, and nutrients, and that can still provide substantial yields of nutritive foods; 4. Biologically-produced pharmaceuticals, cell-based treatments/therapeutics, and materials for on-demand diverse additive manufacturing applications; and 5. Optimized, integrated operation of the above processes.</p>
Status: Active
Description: <p>The Advanced Computational Center for Entry System Simulation (ACCESS) is a comprehensive team of world-leading experts from five U.S. universities (Colorado, Illinois, Kentucky, Minnesota, New Mexico) and three international collaborators (Oxford University, National Research Center-Bari, Instituto Superior Tecnico-Lisbon). Our vision for ACCESS is to radically advance the analysis and design of entry systems through development of a tightly integrated interdisciplinary simulation framework employing high-fidelity validated physics models, driven by quantified uncertainty and reliability, and enabled by innovative algorithms and high-performance computing.</p><p>A NASA Entry System (ES) involves the Thermal Protection System (TPS), including both the heat shield and backshell, along with the supporting structure. An ES is essential to many of NASA’s highest priority space exploration missions, including lunar return to Earth (Artemis), Titan entry (Dragonfly), sending people to Mars (Mars Human Lander), and return of Mars samples to Earth (Earth Entry Vehicle, EEV). Based on the key attributes of these missions, the critical physical processes that drive ES design involve flow phenomena (e.g., chemistry, radiation, turbulence), material response (e.g., ablation) and structural response (e.g., fracture). The ACCESS research plan includes analysis of Dragonfly, Mars Human Lander, and the EEV.</p><p>Entry System analysis and design capabilities currently employed by NASA and its contractors are workable for Artemis, but have critical limitations for the more challenging environments of future missions. A first significant limitation with state-of-the-art (SOA) analysis capabilities is that the uncertainties associated with predicting key quantities of interest are so large that it is not always possible to close on a design cycle. For example, a margin of 100% for turbulent surface heating augmentation is typically employed for Mars entry, and a margin of 40% was used for radiative surface heating for lunar return. Such large uncertainties arise directly from limitations in the accuracy of modeling the key physical phenomena and represent a significant challenge for meeting design requirements, e.g., EEV has a reliability requirement of less than 1 in 106 that cannot be met by SOA analysis capabilities.</p><p>A second significant challenge for the design of ES for NASA reference missions concerns the currently available analysis tools. NASA and the contractors employ a number of computational codes for analysis of ES. However, these tools are labor intensive to apply, their computational performance is limited in part by not taking advantage of emerging computer architectures, and they do not integrate uncertainty and reliability.</p><p>To address these challenges, the ACCESS research plan involves four tightly coupled tasks:</p><p>Task 1: Kinetic Rate and Physical Processes<br />Task 2: Integrated Simulation Framework<br />Task 3: High Fidelity Modeling of TPS Features, Damage, and Failure<br />Task 4: Uncertainty Quantification and Reliability.<br />ACCESS will drive down design margins and quantify uncertainty through an innovative, multidisciplinary research approach. The entry missions targeted involve an enormous number of gas-phase and radiative processes. For example, an ablating hydrocarbon TPS can require chemistry mechanisms with about 40 species and 150 reactions. Backshell heating from radiation can also be significant. To reduce the margin, rates for all key reactions must be estimated using reliable experimental data and scalable statistical inference techniques, and the resulting uncertainty must be quantified. In Task 1, theoretical chemistry will identify the key reactions and determine new rates as needed including those for production of electronically-excited states that radiate. The overall kinetics mechanism, including both ground-state and excited-state reactions, will be evaluated through direct comparisons with experimental data generated in world-class facilities. The quantification of uncertainty associated with the rates will be established in collaboration with Task 4. The rates, along with the quantified uncertainty, will be integrated into the overall simulation tool in Task 2. In Task 3, models for gas-surface kinetics, constructed from molecular beam experimental data, must first be applied at the mesoscale for material response modeling. Our novel approach uses simulations of representative volume elements (RVEs). The RVE simulations will use detailed kinetics information (Task 1) and specific meso-structures (Task 3) as inputs, and will quantify each of the mesoscale modeling components required by the material response model; namely, oxidation evolution, porous flow trends, and thermal, structural, and radiative properties. The RVE simulations will provide natural variability in these models and associated parameters (distribution functions), which is crucial to model a full TPS including uncertainty and reliability. The novel stochastic material response framework (Task 3) will be directly coupled to the overall simulation tool (Task 2) and will be developed within the proposed UQ framework (Task 4). This comprehensive approach spans all of the Tasks and all of the ACCESS universities. Such innovative and multidisciplinary integrated research is absolutely essential to achieving the Vision of ACCESS of reducing the overall margins and improving the reliability for the analysis and design of an ES.</p><p>The primary product of ACCESS is the Integrated Simulation Framework (ISF) that will completely change the paradigm in comparison to SOA capabilities for the analysis and design of ES. The ISF will be developed in Task 2, will integrate the key products of all other Tasks, and will take as its starting point the widely used US3D computational fluid dynamics code. As a fundamental construct in its design, US3D allows the integration of simulation capabilities for a broad range of physical phenomena through specification of plugins. The use of plugins with well-defined interfaces makes it possible to transfer capabilities developed in ACCESS for US3D into other simulation frameworks of NASA and its contractors. Task 4 addresses UQ at the level of individual phenomena in the flow and TPS areas (Tasks 1 and 3) and for overall simulations through the ISF (Task 2). The UQ for Tasks 1 and 3 will break new ground for detailed quantification of uncertainty through close coupling between modeling and experiments. Instead of “validating” the physics models, the contribution of inaccuracy and uncertainty of individual processes to overall risk in the ES design will be quantified and transmitted through the system level simulation. One significant challenge in Task 4 for UQ and reliability is the high computational cost of each full ISF simulation, which may limit the number of sensitivity data points that are generated. To address this challenge, novel algorithms will be explored, such as Discontinuous Galerkin methods and meshless techniques, that have the potential to significantly reduce the time to set up and execute large-scale simulations. Also, key ISF algorithms will be adapted for execution on Peta/Exa scale computer architectures to reduce run time. Emerging UQ approaches will be employed that make careful use of lower fidelity physical models to achieve results consistent with more expensive higher fidelity models but at drastically reduced cost. The successful outcome of the overall Vision for ACCESS will deliver an integrated simulation framework for the comprehensive and affordable design of ES with quantified uncertainty and reliability estimates that will be ready for adoption by NASA and its contractors.</p>
Status: Active
Description: <p>Whether adding a single satellite to a train of historical missions, or launching a vast network of CubeSats, the advent of distributed spacecraft missions (DSMs) marks the transition of traditional mission concepts to the modern era. To meet ever-restricting requirements, DSMs offer an avenue to take full advantage of the truly expansive trade space in space-borne remote sensing mission design. DSMs suffer from a combinatorial increase in trade space size. As such, NASA Technology Roadmaps TA 11.2 highlights a need for modern methods for mission analysis and design. In this proposal, we address this need through the fundamental element in trade space analysis for remote sensing missions: coverage simulation. By reducing simulation time, more variables can be traded in less time, increasing trade study fidelity. This is especially necessary for DSMs, with multiple satellites and multiple configurations per satellite. Our objective is to resolve trade space complexity by proposing a novel gridding method for coverage analysis. We present Iterative Distance Gridding (IDG), which will provide much higher speed and sustained accuracy over wide spatial and temporal domains. This is done by determining grid point distance relative to the track rather than determining whether grid points lie within a polygon, an inefficiency of traditional methods. With such performance, we additionally present satellite data product uncertainty (SDPU) as a coverage metric to enhance trade space analysis. Not only do we seek to reduce the computational burden of trade space analysis, we also have the opportunity to enhance such analysis, directly tying together instrument selection and coverage metrics. This inherently supports NASA objectives to modernize DSM analysis tools.</p>
Status: Completed
Description: <p>The Advanced Space Technology Roadmapping Architecture (ASTRA) project will develop and deploy a state-of-the-art methodology for space technology valuation and technology portfolio construction using both integrated modeling and simulation and rigorous Markowitz portfolio theory. ASTRA builds on the Commercial Space Technology Roadmaps (2016-2018) and will organically integrate with the new NASA technology taxonomy (TX01-TX17), the mission-driven NASA technology roadmaps as well as the TechPort database . The ASTRA methodology consists of four steps, each with its own guiding question: (1) Where are we today ?, (2) Where could we go ? (3) Where should we go?, and (4) Where are we really going? This culminates in Technology Investment Portfolio Valuation, Optimization and Selection. ASTRA enables prioritization of mission-specific and general technology investments in a rational way. This includes the identification of optimal timing and opportunities for synergy. ASTRA will be demonstrated and applied to the entire NASA technology portfolio over a period of 3 years using 5 case studies: Artemis, Mars Sample Return (MSR), Nancy Grace Roman Space Telescope (formerly WFIRST), Earth Observation and Cross-Cutting Technologies. ASTRA will also support the annual NASA technology budgeting and prioritization process. </p>
Status: Completed
Description: The aim of this research is to develop architected materials with pre-programmed temporal responses to environmental stimuli. We refer to these materials as robotic matter. We envision these materials to be used for the actuation of soft robots, compliant systems and reconfigurable structures, as alternatives to external mechanical motors, control systems and power devices. The ability to program materials responses by controlling the microstructures geometry and constitutive materials properties offers exciting opportunities for compliant systems that can interact with their environment. By integrating sensing and actuation capability in the passive response of materials to external stimuli, it is possible to program actuation and deformations in a single integrated architecture. Robotic matter enables significant reduction in the mass and volume of deployable structures and soft robots. This research project focuses on two topics that are important for the development of robotic matter. First, while several stimulus-responsive materials have been used for inducing compelling demonstrations of changes in geometry, temporal programmability has only been shown in a small number of morphing processes that involve the sequential folding of discrete hinges. Our research involves extending this capability to architected materials that can be treated as programmable continua, substantially broadening the range of achievable geometries in shape-morphing systems. Secondly, while the soft robotics community has produced some examples of untethered, passively controlled systems, they are generally limited in their ability to self-propel by a lack of energy density or actuator reversibility. Through this project, we intend to develop soft materials and compliant devices that can undergo repeatable, sequential and energy dense actuation. Finally, we seek to develop a general design methodology for applying these capabilities to the passive control of untethered soft robots, morphing shell structures, and compliant robotic articulations.
Status: Completed
Description: <p>Aerosol deposition (AD) is a novel process which allows for the low-cost formation of fully dense, nanocrystalline, ceramic coatings at room temperature. Ceramics are traditionally processed in excess of 1000⁰C prohibiting production of ceramic films on low melting point substrates. By utilizing the AD process, ceramic films may be coated atop polymeric substrates. Aerosol deposited ceramic coatings provide the unique opportunity to form highly protective coatings, especially on ubiquitous polymeric and composite substrates for space applications. In the harsh environment of low earth orbit (LEO) atomic oxygen plays a major role in the degradation of polymeric materials such as polyimide (PI) Kapton® and polyethylene terephthalate (PET) Mylar®. Atomic oxygen attack causes concern to the longevity of these polymers when used as low thickness reflective blankets. Using AD technology, more reliable coatings of SiO2, and SiO2-polytertrafluoroethylene (PTFE) composite coatings may be achieved. The produced nanocrystalline ceramic coatings proposed here would be part of the TA 10.1.3.1 Technological Area Breakdown Structure (TABS) as a nanomaterial barrier coating to prevent degradation and improve longevity of polymeric materials under LEO conditions. This research will serve to find the most efficient parameters in order to use AD to form these coatings and characterize the coatings surface and protective abilities. A key part of the process will be to characterize the powders to be sprayed in the AD chamber. Characterization of the powders morphology and size distribution will be achieved using Frauenhoffer diffraction particle sizing, a scanning electron microscope (SEM), and an X-ray diffractometer (XRD). These powders will be used as spray deposition parameters are varied in a systematic, iterative fashion until optimal deposition is achieved. This process will be aided by my own experience in the field of ceramic AD coatings. The custom-built vacuum AD apparatus at New Mexico Tech (NMT) will be utilized for fabrication of films. A scanning white light, interferometric, optical profilometer will be used to determine film thickness, roughness and defect (pinhole) density. Atomic force microscopy (AFM) will be used to do the same at a smaller surface spatial wavelength. The Visiting Technologists Experience will be an exceptional opportunity not only for my own goals but for furthering the experiment through the possibility of techniques not available at NMT. These include vacuum deposition of a reflective aluminum layer, scratch testing in order to test the adhesion of the AD coatings, and atomic oxygen erosion testing (possibly at the Glenn Research Center). I hope to demonstrate that the coating can extend the life of reflective blankets used in LEO by providing protection against atomic oxygen degradation, in accordance with the 10.1.3 TABS element. However, the benefits of AD ceramic and ceramic composite coatings in space may extend further. This research may also prove applicable to the outer PTFE layer of woven beta cloth for added protection against micrometeoroids. The research may open the way for AD in other NASA application areas including protective coatings of light weight inflatable habitats, space suits, thermal barrier coatings, radiation barrier coatings and in-space repair of thermal barrier re-entry tiles. This technology has the possibility to aid not only in improvements to the longevity of low earth orbiting systems, but as a new technique to be utilized for protection and repair of systems in all space environments, thus accelerating human progress to the moon, Mars, and beyond.</p>
Status: Completed
Description: <p>An electric field antenna design is presented for the purpose of detecting millimeter-scale orbital debris. Millimeter-scale orbital debris presents a great threat to the safety of spacecraft. Through ground tracking systems such as the Goldstone and Haystack facilities, we can characterize the debris environment for diameters greater than a half a centimeter using radar. For diameters greater than 10 cm, the U.S. Space Surveillance Network can detect the debris. No device is currently available to determine the characteristics below the millimeter-scale debris population, despite the damage they can do. Recent research has shown that as small debris travels through the ionosphere, it will create a solitary acoustic wave in the plasma, called a soliton, that is potentially detectable. Depending on the altitude and relative velocity of the debris particle to the plasma, the solitons created may propagate kilometers ahead of the debris. Millimeter-scale debris may be characterized using an electric field antenna to detect the precursor solitons. To resolve the soliton, which has the same cross-sectional spatial size as the debris and a frequency of a few kHz, fast detections with a large collection area must be made. To prevent missed detections of solitons passing close by, but not interacting with the antenna, a paraboloid reflector will be implemented to increase the collection area. A simulation of a detection event will be done in MATLAB to determine the effect of antenna parameters such as reflector design, antenna size, and sample rate on the data collected. The data will be evaluated based on the ability to rebuild the soliton signature. Experimental data will be taken in a plasma chamber at Marshall Space Flight Center and compared with the simulation.</p>
Status: Completed
Description: The proposed research looks to develop the mathematical framework and algorithm for real-time, on-board optimal guidance using the Theory of Connections (a newly established technique to solve differential equations). Current publications on the Theory of Connections provide machine-level accurate solutions in milliseconds. This provides a foundation for the computation of dynamical equations of motion in real-time in order to make control decisions. Moreover, a preliminary study of this technique applied to optimal guidance type problems has already been conducted validating further work in this area. While the main goal of this proposal is to develop a real-time optimal guidance architecture, it will also further the development of the Theory of Connections as a robust mathematical tool. In general, this has potential to be applied across all fields of engineering where machine level accuracy is necessary in the solution of problems. In all, research in real-time optimal guidance and control is the building block for reduced reliance on Earth based systems for spaceflight and ultimately full spacecraft autonomy.
Status: Completed
Description: The Rotating Magnetic Field (RMF) Thruster is a device inspired by Field Reversed Configuration (FRC) research in both the fusion and electric propulsion community. It uses a pulsed rotating magnetic field to drive plasma currents to produce thrust. Because of its pulsed nature, the resulting high-power thruster would be highly throttleable due to the ability to adjust duty cycle. The RMF current drive mechanism also requires relatively low currents relative to other pulsed inductive thrusters, potentially offering dramatically increased lifetime. Additionally, it would be ideal for in-situ resource utilization (ISRU) applications because the confined nature of the plasmoid and lack of plasma-wetted electrodes ensures minimal erosion of the device even with propellants such as water. However, relatively little work has been done to study the mechanisms behind accelerating the plasma, and measurements of thruster characteristics (thrust, specific impulse, etc.) have never been performed. We propose to study this promising new technology by adding onto the existing analysis of the acceleration of FRC plasmoids, and by testing a real device to achieve the first real measurements of its performance. The results of the theoretical and experimental portions will then be used to begin the optimization of the RMF thruster. This project allows for research which fits in with the expertise and long-term plans already in place in Prof. Jorns lab, while maintaining that the main research effort is in search of a next-generation ISRU-compatible thruster.
Status: Completed
Description: Whether a young Mars harbored microbial life remains unknown. The answer to this question would have ramifications for our understanding of the development of life on both Earth and elsewhere. Searching for life on Mars has been hindered by the difficulty of finding pristine samples that could contain organic compounds. The absence of a substantial atmosphere and global magnetic field has left the top 1-2 m of the planet's surface thoroughly irradiated, necessitating the capture of deeper samples for astrobiological research. Martian lava tube caves present an opportunity to access protected underground samples without the need for heavy and complex drilling equipment. Robust robots capable of traversing lava tube terrain could travel from tube entrances (skylights) and obtain protected samples deeper within the tubes. Technology capable of exploring Martian lava tubes could also be used to map them, as lava tubes are considered to be a possible location for human settlement on Mars. I propose to develop a novel robot design capable of exploring Martian lava tubes. While robots that may be able to navigate this environment exist, none are both small enough that multiple can be sent, but capable of complex maneuvers to traverse obstacles. I propose to design and prototype a 1-2 kg robot to meet these constraints. The starting point will be my research with the Stockton Group at Georgia Tech, during which I have designed a robot that implements positionable arms that pull and climb with continuous tracks. While this design will likely evolve with time, the end result will be capable of reaching pristine samples to perform in-situ analysis within lava tubes. The NSTRF fellowship would allow me to develop this early research into a robust and tested robot design.
Status: Completed
Description: <p>In this proposal, I present a research plan for active exploration and modeling of temporal phenomena to support service robots in long-term deployment settings, such as space station assistive robots like Astrobee. Under this framework, an autonomous robot will plan data collection activities around user-scheduled tasks and routine behaviors, which will be used to construct contextual models of temporal phenomena informing successful task execution. Such modeling will be used, for example, to guide efficient search for objects in inventory management tasks, taking into account likely locations across time, as well as inform when sensor readings should be taken for monitoring system health. Over an extended deployment, the robot will plan data collection over insufficiently modeled contexts to learn an increasingly robust model over time. Additionally, information gathering activities will be scheduled alongside normal tasks in a manner that allows for maximal task efficiency.</p>
Status: Completed
Description: <p>The purpose of this project proposal is to model the damping in magnetorheological (MR) fluid dampers using transient magnetic fields. When MR fluid dampers are used in engineering systems, they are typically accompanied by a constant magnetic field during the system’s operation. There are interactions between the friction force provided by the fluid and inertial forces from the beam, however, that makes the system “freeze” in place, not allowing the system to damp out to its equilibrium position. By changing the magnetic field strength, which changes the fluid’s apparent viscosity and damping characteristics, the force interactions are affected such that the beam can continue to vibrate. This project, therefore, will analyze these transient magnetic fields and how the change, and ultimately, maximize the damping in engineering systems.<br /> <br /> This project will analyze the transient magnetic field characteristics on a sandwich beam with an MR fluid core through three steps. The first step is to complete a numerical analysis using the finite element method, while the second step consists of running an experiment to measure the damping. The results from these two sections will be compared. The third and final section is dedicated to designing a controller that will maximize the beam’s damping by changing the electromagnets’ magnetic field strength, which are part of the constructed beam in the experimental analysis.<br /> <br /> This project meets the criteria for Technology Roadmap 12.2.5.7, “Integrated Adaptive”. This project will focus on active vibration control, and can be integrated into engineering systems, instead of using external dampers that can increase an aerospace vehicle’s mass or volume. The extra mass and volume saved by using integrated MR fluid dampers can reduce mission costs or allow space for other essentials like fuel and equipment.</p>
Status: Completed
Description: Developing resilient materials for in-space applications and extreme environments is essential to produce components that are more reliable and last longer. Additive manufacturing (AM) is an emerging field that offers many unique capabilities compared to traditional manufacturing techniques. Of these capabilities, the ability to control fundamental properties of the material during production, such as the microstructure, is particularly useful to produce better materials. The goal of this research is to investigate the use of AM to actively control microstructure in metals during manufacturing and study how this affects material performance. Initially, a detailed investigation into the degree to which the microstructure can be controlled using various AM techniques and processing conditions will be performed. The second phase of this work is to identify the most promising AM techniques for microstructure control. These techniques will then be used to control the microstructure of components and test how the mechanical properties and resistance to harsh environments are affected. Finally, the performance of these AM components will be compared to traditionally manufactured components to determine how the performance changed. This work will improve the fundamental understanding of using AM for microstructure control, and how this control can be used to enhance material performance in extreme environments. The principal application of this approach is using AM to tailor components for specific extreme environments, resulting in improved materials for a variety of space technology applications.
Status: Completed
Description: <p>In a communications channel, the space environment between a spacecraft and an Earth ground station can potentially cause the loss of a data link or at least degrade its performance. The research plan detailed in this proposal describes an adaptive, intelligent MAC protocol for software-defined radio space-communications applications. It consists of sensing, predictive, and decision mechanisms that will drive an overall framework to sense current channel conditions, predict the near-future channel conditions, and then automatically reconfigure based on these inputs. The reconfiguration of the SDR will be based on attempting to maintain the performance requirements for the data link, such as bit error rate, up-time, reliability, and/or data rate. Upon successful testing onboard the International Space Station using the Space Communications and Navigation (SCaN) Testbed, this research effort will change the TRL level from TRL 3 to TRL 5 in the area of TA05. Ultimately, it will potentially push the state-of-the-art performance limits of a space-based communications network.</p>
Status: Completed
Description: In this study, the applicant (Ms Jaemi Herzberger) will focus on identifying the reliability challenges in long-life electronic systems that have to endure sustained exposure to environmental and operational stresses such as temperature, humidity and power. This topic was selected because electronic systems are a critical component of many projects at NASA dealing with space technology, making their reliability critical to the success of the mission. This research is also the topic of the MS thesis research for Jaemi. Jaemi is currently a senior in her BS program at the University of Maryland (Mechanical Engineering Dept) and has been selected for a highly competitive accelerated MS program in the same department, in view of her academic excellence. The research will be conducted under the auspices of the Center for Advanced Life Cycle Engineering (CALCE) at the University of Maryland in College Park, which is an acknowledged world leader in the Physics of Failure (PoF) approach to develop and qualify complex highly-reliable electronic systems. NASA has been a very active research sponsor at CALCE for over 10 years and is currently a super-member. Over the years, CALCE has collaborated with several different labs and programs at NASA, including JPL, GSFC, HW and NEP. CALCE has also collaborated on study of space electronics with other NASA contractors; such as a study of chip-on-board technology for deep space probes in collaboration the Applied Physics Lab at Johns Hopkins University. For this study, Jaemi is going to use the physics of failure methods developed at the CALCE Center. The first step in this approach is to conduct tailored accelerated stress testing and failure analysis to identify the dominant failure mechanisms. In this study, Jaemi will focus predominantly on temperature, humidity and electrical power as the sources of stress and aging/degradation. The next step is to use well-accepted stress analysis and physics-based failure models, to obtain acceleration transforms that can be used to extrapolate the test results to expected life cycle conditions. The outcome is a quantitative understanding of the life-cycle durability of the product and insights into potential for design improvements. Although, the test specimens that Jaemi will select for this study are from next-generation outdoor solid-state lighting electronics, they share many commonalities with space electronic systems: such as long life (approximately 10-plus years) equipment without maintenance or service; and severe cyclic excursions of power, temperature and humidity. Thus, lessons learned from this project will be of great relevance to space electronics built and deployed by NASA and will be made available to NASA through the CALCE consortium reports. We are requesting 12 months of support under this fellowship, commencing in Aug 2011. At the end of that year, Jaemi expects to graduate with a MS degree. During summer and Fall of 2012, CALCE will make arrangements for Jaemi to spend some time at a particiapting NASA lab, to transfer her research results to mission engineers there and to gain internship experience.
Status: Active
Description: <p>The proposed research will develop an algorithm and software implementation of a customized capability for onboard generation of the end-to-end, multi-phase trajectory from entry interface (EI) to termination of the powered descent, subject to any user-imposed operational and safety constraints and with the minimum propellant consumption. The technical approach is by a recently developed unified optimization theory, Hamiltonian programming method, the knotting technique and other numerical techniques tailored to the problem to make the algorithm more robust and fast. In addition, the particular physics of dynamics and characteristics of the optimal solution of the problem will be exploited for algorithm customization. The work will take two major steps. The first to apply the proposed methodology to the propellant-optimal powered descent problem. The product is a stand-alone algorithm and software that can be applied to powered descent guidance. On the basis of the lesson learned and experience gained, the second step is to develop the algorithm and software for the end-to-end multi-phase trajectory from EI to touchdown, including both atmospheric entry and powered descent phases in an integrated fashion.</p>
Status: Completed
Description: Aerocapture is an orbit insertion maneuver that uses drag of a planetary atmosphere on a spacecraft to transfer it from a hyperbolic trajectory to a closed elliptic orbit. This technique can greatly reduce cost or increase delivered payload mass and it is an enabling technology for otherwise infeasible missions to Jupiter, Saturn, and Neptune (Hall et al, 2005). Although several relatively mature aerocapture technologies are under development, the associated risks of performing this maneuver have prevented them from ever being used on a mission. Current aerocapture devices rely on aeroshells, solid structures that deflect atmospheric flow, and are therefore susceptible to the high heat and dynamic pressure inherent to hypersonic reentry. Aeroshells are limited in size due to launch vehicle constraints and must fly deep in the atmosphere to achieve the necessary drag for orbit insertion. Such trajectories are highly sensitive to perturbations and uncertainties in the local environment, which can be significant in the poorly understood atmospheres beyond Mars. Plasma aerocapture leverages an entry technology called a magnetoshell to achieve orbit with lower heating and dynamic pressures than standard aerocapture systems. A magnetoshell consists of a plasma confined by an applied magnetic field which is fixed to the spacecraft. Some plasma is seeded into the field from onboard fuel storage to initially generate the magnetoshell. Rather than deflect the atmospheric flow as an aeroshell does, the plasma absorbs and utilizes the neutral atmosphere during the maneuver. Thus, the magnetoshell requires little thermal protection since the flow energy is deposited in the plasma and not the spacecraft structure. The plasma is sustained entirely from the mass and energy captured from the atmosphere rather than any onboard fuel and power; only power to the magnet is required to keep the magnetoshell operational. Additionally, the area over which flow interacts with the plasma is defined by the strength of the magnetic field, so the area can be made larger than that of a mechanically deployed decelerator. This means aerocapture is achieved at higher altitudes where dynamic pressure and sensitivity to atmospheric perturbations are lower. By controlling the magnetic field strength, the drag can be modulated continuously, enabling robust control over the flight trajectory. This research aims to determine whether plasma aerocapture is a feasible solution for delivering spacecraft to targets with atmospheres. Because of the novel physics of the magnetoshell, feasibility hinges on multiple questions. First, I will develop an analytic model of the plasma interaction with an atmospheric flow representative of the aerocapture environment. This model will reveal the fundamental physics governing the plasma and the scaling of drag with input parameters such as magnetoshell design and atmospheric conditions. Second, I will develop an experiment to validate the physics observed in the analytic model. This experiment will consist of a subscale magnetoshell impacted by a low-energy neutral beam in a novel “wind tunnel” approach simulating aerocapture conditions. The magnetoshell drag will be measured using a thrust stand and plasma diagnostics will analyze crucial parameters governing performance. Finally, with a solid understanding of these physics, I will develop a tool for simulating trajectories of plasma aerocapture in NASA’s Program to Optimize Simulated Trajectories II (POST2). This module will combine the performance scaling found by the analytic model and experiment with spacecraft configuration parameters so that mission designers can develop plasma aerocapture mission architectures. Addressing these three research areas will ultimately determine whether plasma aerocapture can be reasonably implemented aboard a spacecraft, opening the door to future mission development and solar system exploration.
Status: Active
Description: <p>The project will advance molten regolith electrolysis (MRE), one of the leading processes for extracting oxygen and metal from the lunar regolith, by developing a tapping system to siphon off molten metals from the MRE reactor. The system will be integrated with an aluminum-refinement reactor and a wire-casting system to create high-purity aluminum wire that can be used as feedstock for additive manufacturing on the surface of the Moon.</p>
Status: Completed
Description: <p>The Institute for Ultra-Strong Composites by Computational Design (US-COMP) will serve as a focal point for partnerships between NASA, other federal agencies, industry, and academia to: (1) enable computationally-driven development of CNT-based ultra-high strength lightweight structural materials and (2) expand the resource of highly skilled scientists, engineers and technologists in this emerging field to enhance the U.S. leadership in critical lightweight structural materials. The research objectives of US-COMP are to: Establish a new computationally-driven material design paradigm for rapid material development and deployment Develop a novel UHSL structural material for use in deep space exploration. The panel-level tests and demonstration of the novel materials will be carried out to move the developed technology to TRL-4 or higher Develop modeling, processing, and testing tools and methods for CNT assemblage-based UHSL materials Train a pool of highly skilled scientists and engineers to contribute to the materials development workforce The team will develop the following technologies and have a major impact on the aerospace community: Lightweight structural materials based on 1 dimensional and 1.5 dimensional CNT building blocks with the exceptional strength, modulus, and fracture toughness properties necessary for manned Mars missions and other space explorations A new computationally-driven materials design paradigm to develop the UHSL material of interest and for future rapid materials design and development Fundamental understanding of load transfer and multiscale failure mechanisms of CNT assemblage composite materials to approach their theoretical performance A full set of engineering performance data from for the developed UHSL material A new suite of multi-scale mechanical characterization tools and protocols for CNT materials</p>
Status: Completed
Description: <p>Materials and structures are constantly subject to fatigue and degradation, and monitoring and maintaining civil, space, and aerospace infrastructure is an ongoing critical issue facing our society today. As new materials, such as complex multilayer composites, come into wider use, the need to monitor them is also rapidly growing. Space exploration adds to this need by offering extreme conditions and increased risk associated with material failure. The proposed research seeks to tackle this problem by developing passively-coded miniature embedded wideband microwave sensors, exploring their applicability, and investigating the utility of a novel and unique methodology for inspecting materials and complex structures. Each sensor will consist of a miniaturized wideband antenna specifically designed to have a number of resonances in its reflection property. By using the reflection properties of the antenna, regions in frequency of resonance and reflection can be associated with 0s and 1s to create a specific "code" for that antenna. This code shifts (in frequency) or alters based on the properties and degradation of the material in which the antenna is embedded. These sensors could be embedded in materials and structures such as concrete, a composite fuselage, or an astronauts planetary habitat, and by being passive, the sensors will not need to be energized (i.e., wired in or provided with a power source). In the case of a planetary habitat, an astronaut could easily inspect their home for damage using a simple transceiver, and perform repairs or preventative maintenance if necessary. This practice would increase the astronauts safety and minimize the risk of structure failure while they explore and are faced with the unforgiving environment of space. Because this technology is of such a low TRL nature, its full application range cannot be conceptualized at this point. However, with their low cost nature and versatility, these sensors have the potential to be integrated into many space structures and materials as well as everyday civil and aerospace structures like bridges, parking garages, and planes. Additionally, the sensor data could be used to refine manufacturing processes. This research will be pursued as part of an electrical engineering MS degree at Missouri S&T under the guidance of Dr. Reza Zoughi and the tools needed to engage in this research will be primarily provided through the Applied Microwave and Nondestructive Testing Laboratory (amntl) on campus.</p>
Status: Completed
Description: <p>High voltage (HV) power devices based on silicon carbide (SiC) semiconductor material may offer revolutionary transformations for future NASA space missions, due to the roughly three-fold increase in bandgap of SiC-based devices over traditional silicon (Si)-based devices. The wide bandgap feature enables the SiC device to operate at higher voltages, temperatures, and switching frequencies with greater efficiencies compared to existing Si devices. However, the unique space environment presents a great challenge to the device performance and reliability. To safely deploy SiC power devices for space missions, one has to first answer the question of how SiC-devices survive from the harsh radiation environment in space. Fundamental research into the radiation susceptibility and failure mechanisms of SiC is necessary. The overall goal of the proposed project is to advance the understanding of radiation failure mechanism in silicon carbide (SiC) materials for power devices, and provide the guidelines to design and fabricate SiC-based devices with higher resistance to radiation single-event effects (SEEs).</p>
Status: Completed
Description: <p>Nuclear thermal propulsion (NTP) offers twice the specific impulse of the best chemical combustion engines and can thus halve space mission transit times to allow further exploration and understanding of the universe to become feasible NASA missions. The large specific impulses achieved are due to the ejection of light hydrogen gas at high temperatures sustained by the nuclear fuel elements. One of the most significant challenges in implementing this technology however is producing engines where both the fissionable and containment materials resist hydrogen embrittlement at operating conditions (~2700 K). Currently, ceramic-metallic (CERMET) fuel is used, which embeds chemical vapor deposition (CVD) coated fissionable material in a tungsten matrix. These porous CVD films require microscale thicknesses to begin extending engine lifetimes yet still do not reach the required protection levels. We propose to use atomic layer deposition (ALD) of a chemically-bonded barrier film as a nuclear fuel coating to prevent the reaction of CERMET fuel with the hydrogen propellant. The coating will be designed to resist hydrogen reaction, adsorption, and diffusion, thereby protecting the underlying fissionable uranium fuel material from both chemical redox and reaction which causes embrittlement and fuel loss. The protective, pinhole-free, nanoscale coating will also have a high melting point, thermal conductivity, neutron transparency, and resist both delamination and thermal fatigue caused by thermal expansion mismatch during temperature ramps. ALD utilizes successive self-limiting reactions to offer exquisitely tunable film thicknesses. This attribute will reduce fissionable fuel volume displacement by depositing the thinnest films possible that still resist hydrogen diffusion and mechanical stresses. Both computation and experiment will be used to design and test the best coating materials.</p>
Status: Completed
Description: <p>The goal of this project is to develop the first end-to-end modeling framework to study the plumes produced by electrospray thrusters when integrated on small satellite platforms. These propulsion devices are miniature electric engines that have the potential to provide significant mobility to small spacecraft, enabling a variety of new missions. Electrospray plumes are made of complex particles that must be tracked to ensure proper operation of the thrusters, safety of the scientific instruments, and safe levels of electric charge on the vehicle itself. Our team will integrate a combination of models that capture the physical processes occurring down to the nanoscale (where ion emission occurs) and up to the meter scale (where plumes expand and interact). This research will be performed at MIT’s Space Propulsion Laboratory, where experimental facilities, including a CubeSat testbed, will be used to validate and test model results. The result will be software that propulsion engineers and spacecraft designers can use to design next generation, electrically-propelled CubeSats.</p>
Status: Completed
Description: <p>This study will characterize materials and fabrication techniques for electroadhesion (EA) elastomerfabrics and stretchable EA pads with the objective of manufacturing efficient, space-rated EA devices. EA is characterized by an electrostatic force produced by inputting a DC signal at high voltage (near 5 kV) into adjacent planar electrodes. An electric field is generated from the electrodes to the substrate of choice. Adhesion of the pad with the substrate occurs by Coulombs Force for conductive substrates and Van der Waals Force for nonconductive substrates. This electrostatic adhesion phenomenon allows for active ”on-off” adhesive capabilities. For the purpose of space application, metal electrodes such as Aluminum and space-rated insulating materials should be considered including Kapton polyimide and polypropylene. Fabrication of stretchable EA samples consists of elastomers as insulating materials and liquid metal or conductive polymers as electrodes. Liquid metals, including gallium-indium alloy, as electrodes embedded in an insulating polymer in various patterns will be studied in a vacuum environment, and optimized for application in spacecraft docking, astronaut space suits, and spacewalk gripper devices. The magnitude of the electroadhesive force as the EA pads are stretched must be studied in order to fabricate efficient pads for application, and the limitations of the pads must be determined. In approach to obtaining goals of the study, elastomer-fabric EA pads will be fabricated and shear adhesive forces will be measured, then compared to the controls, which include standard EA pads and PDMS. After it is shown that adding fabric to EA pads improves adhesive forces, materials and fabrication techniques will be optimized, especially with application to space environments. Static response tests will determine the maximum shear force between EA samples and substrate materials, chosen as common materials found in a space environment. Measurements will be acquired from pull tests with an Instron Machine. Further, the pads will be designed in geometries specific to applications in astronaut gripper devices and spacecraft docking. EA prototype devices will be dynamically tested. This study has perceived significance pertaining with NASA interests, specifically on TABS element 4.6.3 in using EA technology as a docking and capture mechanism. As a lightweight, low cost, and low power alternative to traditional mechanical docking mechanisms, EA mechanisms in alignment with TA 4.6.3.1 will be integrated as docking and automated rendezvous systems. Advancing scientific knowledge of EA effects, this technology provides alternative capture devices for future Mars missions, specifically for the Human Exploration and Operations Mission Directorate. Additionally, EA grippers and grabber claws may be used by astronauts on spacewalks to maneuver or collect rocks for scientific studies on Mars. This study will obtain an understanding of the physics of both elastomer-fabric and stretchable EA pads for these applications.</p>
Status: Active
Description: <p>Manned deep-space missions require reliable life support systems to recycle precious oxygen (O2) and water (H2O) from the cabin atmosphere. One attractive system under development is the Series Bosch (S-Bosch) reactor, encompassing both a reverse water gas shift reactor (RWGSr) and a carbon formation reactor (CFR), paired in series. This technology reduces carbon dioxide (CO2) in the presence of hydrogen (H2) into solid carbon and water, from which O2 is electrolytically generated. Unfortunately, the separation of undesired carbon monoxide (CO) from S-Bosch effluent streams remains challenging, in which the membranes developed for this separation are prone to mechanical failure.</p><p>This research aims to develop robust, CO-selective metal-organic frameworks (MOFs) tailored from the ground up for employment in a S-Bosch reactor to regenerate space-cabin air. Notably, selection of an appropriate chemisorbitive mechanism might enable direct separation of CO from effluent steams without prerequisite desiccation. Several promising and highly tunable framework types have been identified that selectively bind CO via π-backbonding interactions and high enthalpies: one framework reversibly binds CO consequent of an adsorbate-induced spin transition, while another framework forms remarkably strong yet thermally reversible π-backbonding interactions between CO and electron-rich CuI centers. Thermodynamic and kinetics selectivities are assessed under a variety of working conditions using isothermal and isobaric measurements. The long-term stability of frameworks to thermal cycling will be assessed under both humid and dry conditions before promising frameworks will be analyzed under realistic conditions in a fixed-bed reactor. Finally, myriad in situ gas-dosed spectroscopic techniques will be employed to establish structure-property relations between metal-adsorbate interactions and thermodynamic and kinetic selectivities for CO under corresponding working conditions.</p>
Status: Completed
Description: <p>This project seeks to design, build, and test a device that is capable of despinning an asteroid without the need for affixing the spacecraft to the surface. This research will use my refined models on asteroid strength to design a neutrally charged beam that can apply a torque onto the asteroid while keeping in a hovered position over the surface through an electric propulsion (EP) system. The first major portion of my research will design and test a component that extracts energy during the creation of the neutral beam to partially supply the EP's energy needs. This component development will incorporate advanced materials, thermoelectric generators, and a possible cooling system. The testing of the power extraction module will occur in a vaccum environment downstream of an ion source such as an EP where I will measure the power output and efficiency of this module. The next brief portion will determine if neutrally charged beams are safer than EP for interacting with the asteroid surface as a proof of concept and clear argument for neutral beams. This will be conducted in a vaccum environment that uses regolith simulant piles to mimic the surface of an asteroid. Finally, a system will be designed, built, and tested that combines a neutrally charged beam, EP, and control system to build the first asteroid despinning device. The design and testing portions will incorporate thermal and plasma analysis to determine the efficiency of the system and its potential for providing the requisite torque needed to despin an asteroid. The NSTRF seeks to develop low-TRL technologies to advance space technology capabilities. My project will create the first power extraction module to neutralize ion flow in a neutral beam emitter. My proposal also is the first to propose using a neutral beam to despin an asteroid and the coupling of this system to an EP. From this, I will build a single module that can be attached as a payload onto a satellite designed to intercept an asteroid or comet. The Human Exploration Destination Systems Roadmap, TABS 7.5.4 looks for technologies that will be able to protect Earth from Near Earth Objects. My technology proposal addresses this need and will be the first step in controlling our solar system's most common bodies.</p>
Status: Completed
Description: Long-term health of astronauts in space relies on effective in-situ diagnoses, management and interventions. However, clinicians are not always present during space exploration. Furthermore, the constraints of space travel make it difficult to bring large scanners such as magnetic resonance imaging (MRI) and X-ray computed tomography (CT) to space. Ultrasound is small and compatible with space exploration. However, ultrasound suffers from a small field of view, and ultrasound images are not easily correlated with anatomical structures, making it difficult to use for astronauts. Recently, significant efforts have been directed towards optical modalities, such as fluorescence imaging, due to their high sensitivity and small size. Miniature imaging systems that can combine the advantages of several modalities will be beneficial for clinical use in space. For effective deployment in space, an imaging system must be accurate, small, safe and easy to use, providing for in-situ diagnosis and treatment assistance. To facilitate long-term health management in space, we propose to develop a prototype miniature multimodal imaging goggle device for guiding medical examinations and interventions during space exploration. We will adapt the imaging goggle concept for aerospace use and expand the present goggle system by integrating multiple imaging modalities, including pre-flight MRI and real-time ultrasound, with the goggle. The 3D multimodal images will be processed, co-registered and displayed in the goggle eyepieces in real-time. The project will be guided by three specific aims: (1) develop a prototype goggle device that can offer fluorescence imaging and wireless communication capacity, (2) integrate MRI and ultrasound with fluorescence imaging, and (3) use multimodal imaging goggle to guide medical examinations and interventions by first responders. With the versatile multimodal imaging goggle at astronauts disposal, wide arrays of medical procedures in space can be enabled. Local and space-earth collaborations can be established to guide various procedures. Minimal medical training will be needed for operating the system owing to its user-friendliness. The proposed multimodal goggle will revolutionize long-duration health management by enabling astronauts to perform complex image-guided examinations and interventions in space. The proposed academic and research program will offer me comprehensive training in aerospace-related bioengineering research, which bridges the gap between medicine and space. I will have opportunities for training in a new research setting that involves multiple disciplines, including medical imaging, aerospace engineering, optical instrumentation, emergency clinical care and translational research. Such experience will not only augment my expertise in biomedical and aerospace instrumentation but also will enhance my vision in interdisciplinary innovative research. Utilizing close collaborations with top aerospace technology researchers and clinicians, I will be able to integrate my capacity in bioengineering with my knowledge in aerospace technology to solve clinical challenges in space. The visiting technologist experience will further sharpen my perception in long-duration health management from an aerospace perspective. Furthermore, the collaborative nature of the proposed training will inspire me to develop management and leadership skills, which will greatly benefit my future career as a researcher who leads a multidisciplinary team solving aerospace-related bioengineering problems.
Status: Completed
Description: <p>My research on topological materials at limited dimensions seeks to lay the groundwork for the next generation of magnetic sensors and low-dissipation circuitry. My research focuses on two compounds: WTe2, a type-II Weyl semimetal, and SnTe, a topological crystalline insulator. I plan to use intercalation and doping to tune the unique electrical properties of WTe2 and SnTe at the nanoscale, where the high surface to volume ratio accentuates the contributions from the topologically protected surface states. Additionally, I will develop novel strategies to mitigate the effects of surface oxidation, which degrades the electrical properties of these compounds. In my research, I will link synthesis to material properties through systematic physical, chemical, and electrical characterizations. The proposed applications based on these topological materials align with the main goal outlined in NASA Technology Roadmap TA 10: Nanotechnology to “provide an overall reduction in vehicle mass while enhancing efficiency, performance, and safety.” This research path can be further focused by major area 10.4, “Sensors Electronics, and Devices.” Collaboration with the NASA Visiting Technologist program will allow further investigation into the radiation stability of topological material based devices.</p>
Status: Completed
Description: <p>Within the past two decades, the detection of lava tubes on the Moon and Mars has revealed potential locations that could be susceptible to life beyond Earth. While missions to explore planetary caves through skylights have been proposed, they are prohibitively expensive and require the most advanced mobility systems to traverse perilous terrain; it is recommended to survey a variety of locations to determine the most viable location for future mission success.<br /><br />Ground Penetrating Radar (GPR) is currently used to locate voids when their vicinity is known. This naturally leads to the question, how can existing subsurface imaging technology be used to better explore unfamiliar spaces rather than passively identifying features when their general location is known in advance? We propose a learning-based approach to identify relevant subsurface features around and above planetary caves to plan optimal trajectories for exploratory ground and aerial vehicles.<br /><br />GPR can be used to characterize the subsurface as a robot traverses a trajectory to determine how to optimally explore an unknown space. By understanding the recurrence of subsurface features, a robot can optimally re-plan its trajectory to follow a path greater with certainty of reaching a desired goal. In order to better detect features indicative of planetary caves, a multimodal sensing approach will be used to classify detectable surface, subsurface, thermal, and magnetic properties. Heterogeneous multi-agent planning can be used as a force multiplier to more quickly search spaces with systems of varying capability.<br /><br />This work is applicable to analysis of radar feedback from the Mars Reconnaissance Orbiter and to support efficient subsurface modeling for the Mars 2020 Radar Imager for Mars' Subsurface Experiment (RIMFAX). The methods proposed for sensing and planning will help NASA's missions to characterize the Martian and lunar subsurface and guide future expeditions to explore planetary pits and caves.</p>
Status: Completed
Description: The dynamic stability of blunt bodies during planetary entry is difficult to quantify as computational methods have yet to demonstrate accurate predictive capabilities and experimental methods cannot explicitly measure damping derivatives. Ballistic range testing has been used in the past to determine dynamic behavior of blunt body vehicles by firing test models down a test range from a gun at low supersonic Mach numbers. Photographs are taken of the test model during flight to monitor the capsule's position and angle. A 6-degree of freedom simulation is then fit to the data points captured by the photos and the capsule aerodynamics are returned. This method is an imperfect test set-up as the uniformity of conditions throughout the test range and the initial release state is variable. In addition, the primary test range used to capture data for the MSL entry vehicle, Eglin Air Force Base, was recently decommissioned. The aim of this project is to conduct a feasibility study in order to determine design requirements for a magnetic suspension system in the NASA GRC (GRC) 225 square centimeter Supersonic Wind Tunnel. This much-needed alternate method has the potential to measure damping coefficients more accurately than traditional ballistic range testing and wind tunnel tests with stings. In the proposed experimental set-up, a magnetic suspension system will balance the aerodynamic, gravitational and magnetic forces so the free-to-oscillate model is held in the test section. High-speed cameras will capture the model's position and angle of attack over time and a trajectory will be fit to these data points, much like ballistic range testing. Although magnetic suspension has been used in the past, the proposed system will be a new, innovative implementation of this technology. Blunt body models have never been tested using magnetic suspension and a completely new positioning system will have to be designed, making this project a challenging design problem. The blunt body test models will comprise a non-magnetic material surrounding a spherical iron core. The geometry of the test model itself places a size limitation on the spherical iron core so the suspension system will have to be powerful enough to overcome this constraint. Initial design questions regarding system implementation will be analyzed and answered by assessing problems in the wind tunnel operation, the magnetic suspension system and the design of the model. These problems will be evaluated using MATLAB for simulation purposes and wind tunnel tests. The main design questions to be answered include determining the lowest possible operating dynamic pressure so minimize the force on the magnet through a wind tunnel test, defining the allowable size of the model to avoid blockage but to provide enough magnetic force, and finally resolving the physical constraints of necessary visual and maintenance access despite a potentially massive magnetic suspension system surrounding the tunnel. This project is important because a deep understanding of the behavior of capsules during entry is necessary for trajectory analysis as well as the safety of robotic or human missions. Magnetic suspension would allow for inexpensive testing of blunt body capsules so that dynamic aerodynamics coefficients can be determined to an improved or similar degree of accuracy as ballistic range testing. This project would serve to answer design questions that would be used to create an extremely beneficial modeling tool in the GRC 225 square centimeter tunnel as well as open the door to impactful innovations in magnetic suspension.
Status: Active
Description: <p>The project will develop methods for teams of robots to jointly overcome environmental hazards on the Moon by attaching to each other to form larger and more stable, maneuverable structures. The robots will use their interactions with the ground to form a map of safe and risky terrain, attach to each other as support when the ground traversal risk is high, move in a coordinated fashion once joined, and, once the maneuver has been successfully completed, separate to continue their original individual missions.</p>
Status: Completed
Description: <p>Proposal evaluation of pre-Phase A mission concepts remains to be a human-dominated effort requiring the expertise of subject matter experts (SMEs) to determine whether or not candidate proposals hold merit in achieving the goals set out by the field of study to which the Request for Proposals (RFP) belongs. However, given the entirely human effort involved with evaluating and adjudicating a submission pool of proposals, challenges in evaluation consistency and agility remain as proposals are typically in the form of unstructured documentation. With somewhat recent advancements in computation ability, coupled with the rise of artificial intelligence and machine learning in all practices of science and engineering, there exists a notion of opportunity in applying semantic-based, computer-powered approaches in supporting the proposal evaluation process. This research proposes a natural language processing (NLP)-based proposal evaluation tool that may augment the reviewer’s capability in determining the utility of an overall portfolio of proposals in achieving the objectives set out by the scientific community. For context, and evaluation of efficacy, the results of the Astrophysics 2010 Decadal Survey will be used as the primary point of comparison.</p>
Status: Completed
Description: <p>DoSEN is an early-stage space technology research project with the sole objective of developing the concept and demonstrating the proof-of-principle of a space radiation instrument possessing unprecedented performance capabilities while requiring only minimal resources (mass, volume, power, cost). DoSEN combines two advanced complementary radiation detection concepts that present fundamental advantages over traditional radiation detectors, but requires proof-of-concept so that DoSEN may be readily implemented on future missions. DoSEN not only measures the energy but also the charge distribution (including neutrons) of energetic particles that affect human (and robotic) health in a way not presently possible with current radiation instruments. Thus, DoSEN lays the foundation for a new generation of radiation instruments for the next phase of NASA’s human and robotic exploration.</p>
Status: Active
Description: <p>The Electrically Actuated Quick-Disconnect Coupling is a very low leakage (Dry) make/break cryogenic fluid compatible coupling that has broad application for in-space and Lunar surface refueling. This technology enables the development of vehicle on-orbit and/or on-surface cryogenic fuel transfer/refueling capability.</p><p>Project includes multiple additively manufactured components, including two independent (male and female) dual-sealing housings designed for cryogenic propellant compatibility; a coupling mate/de-mate geared rotary actuator; mated, open and close position sensors; and an optional extend/retract linear actuator system.</p>
Status: Completed
Description: <p>The challenge provides opportunities to develop a wide range of innovative methods to insert the sample, provide sample containment, erect the launch vehicle and deploy the sample container with limited human intervention and validate a reliable methodology. This challenge especially seeks to engage the amateur robotics and rocketry communities to provide solutions.</p>
Status: Completed
Description: <p>Lunar night poses a significant thermal challenge to small, low power payloads, rovers and landers. Due to the slow rotation of the lunar surface, the environmental temperature drops to below 100K for approximately 14 earth days. In order to enable long duration science missions on the lunar surface it is necessary to maintain the electronics above survival temperature during the lunar night. The Apollo astronauts went to moon during early Lunar morning, which is a relatively benign thermal environment. In contrast, Lunar Landers and Rovers must be able to survive and function over multiple Lunar Day/Night cycles. It has been estimated that for every watt of power generated by batteries during lunar night an additional 5kg of mass is required. Surviving multiple lunar cycles without the use of active power sources will require advanced thermal management techniques. In this SBIR program, Advanced Cooling Technologies, Inc. (ACT) will develop a toolbox of thermal devices that can be combined into fully passive Thermal Management Systems (TMSs) for Lunar Landers and Rovers. There are four parts of a TMS: (1) Heat Acquisition, collecting heat from electronics, (2) Heat Transport, (3) Heat Rejection, and (4) Heat Storage. The heat transport must use a Variable Thermal Link, which transports heat with minimal ΔT during the day, and passively shuts down at night, minimizing heat losses. Over the past decade, ACT has been developing five types of variable thermal links, Variable Conductance Heat Pipes (VCHPs) with warm and cold reservoir, VCHP Loops, and conventional and 3-D printed Loop Heat Pipes (LHPs) with Thermal Control Valve (TCVs). On the proposed program, ACT will develop LHP TCVs and a high-power thermal switch. ACT and Astrobotic will conduct trade studies to optimize designs for Landers and Rovers, and then fabricate and test a Lander and Rover concept in a relevant environment.</p>
Status: Completed
Description: <p>This project matured critical technologies that enable precision and soft landing on the Moon. The project team integrated TRN, navigation doppler lidar, and altimetry sensors and conducted two flight tests prior to lunar mission implementation. Testing was performed at approximately 100 km altitude on board the Blue Origin New Shepard vertical takeoff vertical landing suborbital vehicle. This project completed in calendar year 2021 with each sensor achieving various levels of performance. Several of the sensors are manifested to be tested on CLPS missions in the future. </p>
Status: Completed
Description: <p>We propose to perform an end-to-end system-level study of how to build a very large low frequency (5-40 MHz) radio observatory, “FarView,” on the lunar farside using lunar regolith materials. FarView will be a sparse array of ~100,000 dipole antennas populating a ~20x20 km area. The innovative technology elements enabling FarView will be the near exclusive use of ISRU and on-site manufacturing of almost all system elements for the radio array, including power generation and energy storage systems. FarView science is focused upon investigation in exquisite detail of the unexplored Cosmic Dark Ages using the highly redshifted hydrogen 21-cm line and identifying the conditions and processes under which the first stars, galaxies, and accreting black holes formed No equivalent observatory exists today. This radio telescope will be the first of its kind at this scale and sensitivity and will open a new window (low frequency radio) into the early universe, analogous to the detection of gravitational waves by LIGO and the details of the CMB by Planck. These measurements cannot be made from Earth due to Earth-generated radio noise and the ionosphere. FarView will be evolvable and long-lived using in-situ manufacturing techniques and occasional system upgrades from Earth. It will be of lower cost and longer lifetime than a complete antenna array launched from Earth. Development of lunar surface infrastructure (power systems, energy storage systems, in-space manufacturing assets, space mining assets) to enable future lunar surface scientific and commercial missions. Extraction and refinement of oxygen and metallics from regolith processing activities to be used for future lunar outpost and other in-space manufacturing and human spaceflight activities on the lunar surface and in-space. With the NASA Artemis Program now underway, this study will provide a timely assessment of the value and needs of this important scientific observatory and develop technologies to enable a sustained lunar presence.</p>
Status: Active
Description: <p>The project looks at lightweight, multifunctional materials technology tailored for use in extreme space environments. These extreme environments include those found on orbit, on the surfaces of planetary bodies such as the Moon and Mars, in the atmospheres of planetary bodies such as Venus or the Earth and Mars, especially during (re)entry. The extreme environments relevant to space exploration and science also include those found inside spacecraft and surface systems. Examples of the extreme environments inside spacecraft and surface systems include those found in the reactors, heat exchangers and other components in nuclear thermal propulsion, nuclear electric propulsion as well as surface nuclear power generation and distribution. Extreme environments are also found in other spacecraft and surface systems such as thermal control loops, radiators and electronics assemblies supporting habitats, science instruments, vehicles and spacesuits. The multifunctional materials technology aims to provide structural, thermal, radiation resistance and electrical functions, among others in conditions of extreme maximum and minimum temperatures, temperature cycling, abrasive dust, ionizing and non-ionizing radiation, corrosive refrigerants and fuels as well as ultrahigh vacuum. The multifunctional materials technology to address these challenges includes zero, one and two-dimensional nanomaterials, thermoset and thermoplastic polymer matrix composites incorporating the nanomaterials and ceramic matrix composites such as carbon-carbon. Nanomaterials such as carbon and boron nitride nanotubes, graphene and metallic nanowires and particles provide a range of properties not found in the bulk due in part to their large specific surface area and other phenomena that occur at the nanoscale. Direct use of those nanomaterials or their incorporation into suitable matrixes provides materials technology for spacecraft and surface systems components suited for various applications in extreme environments. </p>
Status: Active
Description: <p>Food and nutrition are critical to health and performance and therefore the success of human space exploration. However, the shelf-stable food system currently in use on the International Space Station (ISS) is not sustainable as missions become longer and further from Earth, even with modification for mass and water efficiencies. Bioregenerative foods as part of the astronaut diet are expected to provide whole food nutrition, improve menu variety, and positively impact behavioral health. Significant advances in both knowledge and technology are still needed to inform productivity, nutrition, acceptability, safety, reliability, and operations of bioregenerative food systems. Sierra Space's Hydroponic/Aeroponic Nutrient Delivery in Volumetrically Efficient Garden (HANDIVEG) is designed to enable continuous crop production in microgravity. HANDIVEG tests volume optimization concepts and uses soilless water and nutrient delivery technologies similar to eXposed Root On-Orbit Test System (XROOTS) <a href="https://techport.nasa.gov/projects/94182">https://techport.nasa.gov/projects/94182</a>. HANDIVEG is designed to grow multiple crop cycles. The Phase B grant advances the technology and design to demonstrate functionality on the ground with a follow-on contract planned to test the flight design in Ohalo III. Ohalo III is a prototype crop production system that will validate water/nutrient delivery and volume optimization, of candidate root module systems like HANDIVEG and advance knowledge on crop production operations which will inform design decisions for a future crop production system intended to be deployed on Deep Space Transit missions.</p>
Status: Completed
Description: <p>Food and nutrition are critical to health and performance and therefore the success of human space exploration. However, the shelf-stable food system currently in use on the International Space Station (ISS) is not sustainable as missions become longer and further from Earth, even with modification for mass and water efficiencies. Bioregenerative foods as part of the astronaut diet are expected to provide whole food nutriti