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At least 685 records · Page 38

In-Situ Testing Methods for Mixed-Mode Harsh Environments

Future NASA missions are driving a need for instrumentation and space electronics that will operate at extreme temperatures, with low mass and extended deployments. This need results in devices that will experience dose damage at both low and high temperatures that will suppress annealing and induce accelerated wear out issues. Therefore, the ability to perform radiation tests on devices at temperature is critical. This paper analyses the methods and process to enable these test as developed at the JPL Dynamitron Facility. Since electronics are the radiation source for this facility, the steps to ensure parity with cobalt-60 testing are discussed. Also discussed are the implications for system level testing and mixed radiation mode testing for highly integrated and scaled devices.

Scheick, Leif Z↗

Modeling Entry Systems to Explore Our Solar System

Exploration of our Solar System is a foundational element of NASA’s identity. Delivering a scientific payload through an atmosphere to the surface of a planetary body requires safely navigating the extreme temperatures and stresses generated by flying many times the speed of sound. An entry system is the outer shell of a vehicle designed to protect the payload and, as a single point of failure for a mission, reliability is paramount. Unfortunately, it is not possible to fully replicate the flight environment in ground test facilities – so how do we confidently design a vehicle that needs to work the first time, every time? Modeling and simulation are critical tools for filling gaps in ground test capability and providing traceability from ground to flight. Modeling an entry system is a truly interdisciplinary effort, requiring knowledge of fluid dynamics, high-temperature chemistry, radiation, materials science, structural dynamics, guidance and control – and, finally, the mathematical and computing capability to pull it all together. In this talk, Dr. Michael Barnhardt will discuss the latest research in modeling entry systems and how it is being used in NASA’s exploration missions.

Entry systems↗

Radiation Tolerance and Mitigation for Neuromorphic Processors

Neuromorphic processors are designed to execute Deep Neural Networks (DNNs) at very high speed using only a fraction of the electrical power needed to run a DNN on a traditional CPU or GPU. This unique capability makes Neuromorphic processors a prime candidate for space systems, where advanced computational tasks like image analysis, depth map reconstruction, or rover control need to be executed in a power-starved environment. In contrast to the growing number of applications of Neuromorphic processors in smart phones, the automotive and robotics domain, the space environment is unforgiving because of extreme temperatures and high levels of radiation. Any space system, operating beyond LEO requires computing hardware that is resilient against radiation effects. However, Neuromorphic processors have not yet been designed or tested for their radiation tolerance. In this report, we consider traditional methods of detection of radiation events and mitigation via redundancy and gauge their effectiveness on DNNs. In contrast to traditional flight software, however, neural networks represent a statistical algorithm, which might affect its resilience against radiation events. We will focus on the analysis of the tolerance of DNNs with respect to radiation events and discuss techniques to detect radiation hits using on-chip triple modular redundancy (TMR) on an Intel Loihi neuromorphic processor and to mitigate radiation damage. We describe an architecture for on-chip TMR for the Intel Loihi and present results of initial experiments.

Neural Networks↗

Integral Channel Nozzles and Heat Exchangers using Additive Manufacturing Directed Energy Deposition NASA HR-1 Alloy

Heat exchangers for use in propulsion applications are very critical components because they must be efficient, compact and light and often operate with working fluids at extreme temperatures or pressures or both. Various components and systems use heat exchangers such as combustion chambers of gas turbines and internal combustion engines, fuel cells (air supply and thermal management), electric batteries (thermal management), evaporators and recuperators of waste-heat-to-power systems, and rocket engines. Even if the results are more generally applicable, the heat exchangers applications to which this study is more closely related are regeneratively cooled rocket nozzles and chambers, and repressurization systems for the launch vehicles. These components are often thin-walled and contain pressurized fluids, like propellants at cryogenic or elevated temperatures. Given that the environments that these propulsion components must endure are challenging, the manufacturing to meet these specifications often require long lead times due to specialty processes and unique tooling associated with the combined thin-wall integral channel and large-scale structures. Additive manufacturing (AM) offers programmatic advantages for reduction in processing time and cost in addition to various technical advantages, including the possibility to achieve enhanced hardware complexity targeted to superior performance, part consolidation, and the capability of processing of novel alloys. While AM is already being utilized for heat exchanger components in propulsion applications, almost all these AM components are made by means of Laser Powder Bed Fusion (L-PBF). L-PBF allows for fine features but is rather limited with respect to the overall size of the components that can be manufactured. Recent developments are maturing the Laser Powder Directed Energy Deposition (LP-DED) process which may be used, for example, to make integral channel thin-wall regeneratively-cooled rocket nozzles with diameters greater than 1 m. This paper highlights some integral channel heat exchanger demonstrator hardware applications of LP-DED, as well as the characterization of this process in combination with the use of the NASA HR-1 alloy. To properly utilize LP-DED for heat exchanger manufacturing, various aspects are being characterized such as geometry limitations, measurement of surface texture and geometric angled surfaces, surface enhancements for internal channels, and material evaluation. NASA HR-1 (FeNi-Cr) is a high strength hydrogen resistant superalloy developed for use in aerospace applications, such as heat exchangers. Some aspects and considerations about the design of heat exchangers are summarized together with data relevant to LP-DED manufacturing in combination with the NASA HR-1 alloy. Microchannels were successful deposited down to 2.54 mm and 1 mm wall thickness, wall angles of 30°, both with high reproducibility. It was also found that the areal surface roughness is highly dependent on the size of the powder feedstock used for deposition. The characterization of these LP-DED features is critical for fluid flow and heat transfer predictions as it can be exploited to enhance heat transfer at the cost of increased pressure drop.

Additive Manufacturing↗

Science Autonomy for Ocean Worlds Astrobiology: A Perspective

Astrobiology missions to ocean worlds in our solar system must overcome both scientific and technological challenges due to extreme temperature and radiation conditions, long communication times, and limited bandwidth. While such tools could not replace ground-based analysis by science and engineering teams, machine learning algorithms could enhance the science return of these missions through development of autonomous science capabilities. Examples of science autonomy include onboard data analysis and subsequent instrument optimization, data prioritization (for transmission), and real-time decision-making based on data analysis. Similar advances could be made to develop streamlined data processing software for rapid ground-based analyses. Here we discuss several ways machine learning and autonomy could be used for astrobiology missions, including landing site selection, prioritization and targeting of samples, classification of “features” (e.g., proposed biosignatures) and novelties (uncharacterized, “new” features, which may be of most interest to agnostic astrobiological investigations), and data transmission.

ocean worlds↗

Integral Channel Nozzles and Heat Exchangers using Additive Manufacturing Directed Energy Deposition NASA HR-1 Alloy

Heat exchangers for use in propulsion applications are very critical components because they must be efficient, compact and light and often operate with working fluids at extreme temperatures or pressures or both. Various components and systems use heat exchangers such as combustion chambers of gas turbines and internal combustion engines, fuel cells (air supply and thermal management), electric batteries (thermal management), evaporators and recuperators of waste-heat-to-power systems, and rocket engines. Even if the results are more generally applicable, the heat exchangers applications to which this study is more closely related are regeneratively cooled rocket nozzles and chambers, and repressurization systems for the launch vehicles. These components are often thin-walled and contain pressurized fluids, like propellants at cryogenic or elevated temperatures. Given that the environments that these propulsion components must endure are challenging, the manufacturing to meet these specifications often require long lead times due to specialty processes and unique tooling associated with the combined thin-wall integral channel and large-scale structures. Additive manufacturing (AM) offers programmatic advantages for reduction in processing time and cost in addition to various technical advantages, including the possibility to achieve enhanced hardware complexity targeted to superior performance, part consolidation, and the capability of processing of novel alloys. While AM is already being utilized for heat exchanger components in propulsion applications, almost all these AM components are made by means of Laser Powder Bed Fusion (L-PBF). L-PBF allows for fine features but is rather limited with respect to the overall size of the components that can be manufactured. Recent developments are maturing the Laser Powder Directed Energy Deposition (LP-DED) process which may be used, for example, to make integral channel thin-wall regeneratively-cooled rocket nozzles with diameters greater than 1 m. This paper highlights some integral channel heat exchanger demonstrator hardware applications of LP-DED, as well as the characterization of this process in combination with the use of the NASA HR-1 alloy. To properly utilize LP-DED for heat exchanger manufacturing, various aspects are being characterized such as geometry limitations, measurement of surface texture and geometric angled surfaces, surface enhancements for internal channels, and material evaluation. NASA HR-1 (FeNi-Cr) is a high strength hydrogen resistant superalloy developed for use in aerospace applications, such as heat exchangers. Some aspects and considerations about the design of heat exchangers are summarized together with data relevant to LP-DED manufacturing in combination with the NASA HR-1 alloy. Microchannels were successful deposited down to 2.54 mm and 1 mm wall thickness, wall angles of 30°, both with high reproducibility. It was also found that the areal surface roughness is highly dependent on the size of the powder feedstock used for deposition. The characterization of these LP-DED features is critical for fluid flow and heat transfer predictions as it can be exploited to enhance heat transfer at the cost of increased pressure drop.

additive manufacturing↗

Initial Results of the MISSE-Flight Facility Polymers and Composites Experiment 1-4 (PCE 1-4)

Spacecraft in low Earth orbit (LEO) are subjected to harsh environmental conditions, including radiation (cosmic rays, ultraviolet (UV), x-ray and charged particle radiation), micrometeoroids and orbital debris, temperature extremes, thermal cycling, and atomic oxygen (AO). These environmental exposures can result in erosion, embrittlement and optical property degradation of susceptible materials threatening spacecraft performance and durability. To increase our understanding of effects such as AO erosion and radiation induced embrittlement of spacecraft materials, NASA Glenn Research Center has developed a series of experiments that are flown as part of the Materials International Space Station Experiment (MISSE) missions on the exterior of the International Space Station (ISS). These experiments have provided critical space environmental durability data such as AO erosion data of polymers and composites, and radiation induced mechanical property degradation of spacecraft insulation materials, after long term space exposure. In continuing these studies, four Glenn experiments with 365 flight samples have been flown on ISS’s external MISSE-Flight Facility (MISSE-FF). These experiments are the Polymers and Composites Experiment-1 (PCE-1) flown as part of the inaugural MISSE-9 mission, the PCE-2 flown as part of the MISSE-10 mission, the PCE-3 flown as part of the MISSE-12 and MISSE-15 missions, and the PCE-4 flown as part of the MISSE-13 mission. The primary objective of the PCE 1-4 experiments is to determine the AO and radiation durability of spacecraft polymers and composites. In addition, each experiment has a wide variety of spacecraft materials and hence they each have numerous additional sample objectives. Each of the PCE 1-4 is designed to examine the consequences of AO interactions including AO erosion yield (Ey) and optical and thermal property characterization. Several polymers were flown in both ram and zenith flight orientations to determine the effect of varying solar to AO ratios on Ey. Common spacecraft materials including Teflon FEP, white Tedlar and Upilex-S were included on multiple MISSE missions so erosion dependence on environment exposure can be determined. The PCE-1 includes epoxy composite samples with varying ZnO levels to determine the effect of inorganic filler level on AO durability. And, a variety of samples were flown to characterize AO scattering and AO undercutting processes. All four PCE experiments include samples to provide better insight into radiation durability of polymers and composites. The MISSE-9 PCE-1 includes Teflon FEP tensile samples flown in the wake and zenith direction so variations in radiation exposure from the different flight directions can provide insight into radiation induced embrittlement of Teflon FEP. Teflon FEP tensile samples were also flown in the wake direction as part of the MISSE-13 PCE-4. In addition, shape memory alloys, shape memory composites, melanin based composites, stressed and unstressed gossamer sun shield materials, coated and uncoated docking seal samples, and new solar cell cover slides were flown for space radiation durability and/or shielding assessment. This paper provides an overview of Glenn’s PCE 1-4 MISSE-FF experiments and provides initial post-flight observations and results.

atomic oxygen↗

Developing a Tool to Collect Microbiological Samples in Space

We developed and tested a tool to collect aseptic samples during extravehicular activity or space walks. This tool can withstand the extreme temperature (-92 – 90 ˚C) and pressure variations without compromising the sterility of the collection device or the integrity of the sample. Results from ground testing the tool demonstrate that external surfaces of space suits are not sterile and that a wide variety of human associated bacteria and some fungi can survive at least seven hours of exposure to vacuum. These bacteria include non-spore forming organisms like Staphylococcus that are not normally considered extremophiles We plan to use this tool to characterize the exterior of the International Space Station. We expect the results of this work to guide the planetary protection requirements and contamination control strategy for crewed missions to Mars. This tool could also be used to monitor contamination associated with the Artemis missions to the moon or collect aseptic samples robotically in environments that are not suitable for human exploration.

A B Regberg↗

Initial Exploratory Study of the Impacts of Climate Change on Air Traffic Operations

Climate change is already happening and is projected to accelerate in the future. It will persist for the foreseeable future, even with optimistic projections of technological advances and behavior changes. It will make aviation more and more challenging over time. Among other things, it is expected to cause increased severe weather, more extreme temperatures, and rising sea levels that constrain when, where, and how aircraft can fly. NASA has many prior, ongoing, and upcoming efforts towards mitigating the impacts of aviation on climate change. There is also a need to perform a comprehensive investigation of the reverse: that is, the impacts of climate change on aviation. This is an initial exploratory study on this topic utilizing the NAS Digital Twin—composed of the ATM TestBed simulation platform and NAS Digital Twin airspace management algorithms—to run NAS-wide simulations with Convective Weather Avoidance Model polygons at different avoidance thresholds to emulate the increase in severe weather that could manifest due to climate change. It was found that air traffic management may be able to limit the impact of climate change in terms of delay and fuel burn. However, increased severe weather due to climate change can make separation—particularly, aircraft-to-weather separation—more challenging by reducing available airspace and constraining the solution space. Challenging situations were identified and corresponding potential solutions were proposed towards ensuring air traffic operations continue to be robust and resilient to the impacts of increased severe weather due to climate change.

climate change, weather, air traffic operations↗

Real-time rapid leakage estimation for deep space habitats using exponentially-weighted adaptively-refined search

The recent accelerated growth in space-related research and development activities makes the near-term need for long-term extraterrestrial habitats evident. Such habitats must operate under continuous disruptive conditions arising from extreme environments like meteoroid impacts, extreme temperature fluctuations, galactic cosmic rays, destructive dust, and seismic events. Loss of air or atmospheric leakage from a habitat poses safety challenges that demand proper attention. Such leakage may arise from micro-meteoroid impacts, crack growth, bolt/rivet loosening, and seal deterioration. In this paper, leakage estimation in deep space habitats is posed as an inverse problem. A forward pressure-based dynamical model is formulated for atmospheric leakage. Experiments are performed on a small-scaled pressure chamber where different leakage scenarios are emulated and corresponding pressure values are measured. An exponentially-weighted adaptively-refined search (EWARS) algorithm is developed and validated for the inverse problem of real-time leakage estimation. It is demonstrated that the proposed methodology can achieve real-time estimation and tracking of constant and variable leaks with accuracy.

Deep space habitats↗

Eastern Indigo Snake (Drymarchon couperi) Shelter Site Use in Peninsular Florida and Implications for Habitat Conservation

Shelters are critical for many species as protection from predators and extreme temperatures. Successful conservation of reptiles requires understanding both shelter site requirements and availability. The Eastern Indigo Snake (EIS) is endemic to the southeastern United States and is federally listed. Recovery has focused on maximizing unfragmented landscapes, with less attention on fine-scale features such as shelter sites. In the northern EIS range, Gopher Tortoise (Gopherus polyphemus) burrows are used extensively for shelter. Although EIS in peninsular Florida often shelter in tortoise burrows, they also use other shelters where tortoise burrows are scarce or absent. Solely focusing EIS survey and management efforts where Gopher Tortoises are present may overlook occupied habitats and misallocate resources. We investigated the importance of different shelter sites in central Florida using data from radio-tracked EIS. We modeled the use of shelter categories as a function of sex, season, and habitat using Bayesian multinomial generalized linear models. Results showed that EIS in peninsular Florida used Gopher Tortoise burrows across all seasons and habitats. Tortoise burrow use was highest in xeric habitats and lowest in mesic habitats where burrows are most and least abundant, respectively. There was less variability in shelter site use in disturbed habitats and flatwoods. Cool season tortoise burrow use across sexes and habitats in our study was much lower than in southern Georgia. Our results indicate that EIS are less dependent on Gopher Tortoise burrows in peninsular Florida and that suitable habitats with few or no tortoise burrows could still provide conservation value for EIS.

Bayesian hierarchical modeling↗

Irrigation in the Earth System

Irrigation accounts for ~70% of global freshwater withdrawals and ~90% of consumptive water use, driving myriad Earth system impacts. In this Review, we summarize how irrigation currently impacts key components of the Earth system. Estimates suggest that more than 3.6 million km 2 of currently irrigated land, with hot spots in the intensively cultivated US High Plains, California Central Valley, Indo-Gangetic Basin and northern China. Process-based models estimate that ~2,700 ± 540 km 3 irrigation water is withdrawn globally each year, broadly consistent with country-reported values despite these estimates embedding substantial uncertainties. Expansive irrigation has modified surface energy balance and biogeochemical cycling. A shift from sensible to latent heat fluxes, and resulting land–atmosphere feedbacks, generally reduce regional growing season surface temperatures by ~1–3 °C. Irrigation can ameliorate temperature extremes in some regions, but conversely exacerbates moist heat stress. Modelled precipitation responses are more varied, with some intensive cropping regions exhibiting suppressed local precipitation but enhanced precipitation downstream owing to atmospheric circulation interactions. Additionally, irrigation could enhance cropland carbon uptake; however, it can also contribute to elevated methane fluxes in rice systems and mobilize nitrogen loading to groundwater. Cross-disciplinary, integrative research efforts can help advance understanding of these irrigation–Earth system interactions, and identify and reduce uncertainties, biases and limitations.

Climate sciences↗

Welding in Space: Past, Present, and Future

It has been over fifty years since the first welds were made in space by Soviet cosmonauts on Soyuz-6 in October of 1969. The United States performed bead-on-plate welding, brazing, and metal melting experiments onboard the Skylab orbital space station several years later in 1973. Finally, Soviet cosmonauts departed their Salyut-7 capsule and made the first (and last) welds in open space in 1984. Progress on further demonstrations of welding in space stagnated, and subsequent microgravity welding research work shifted to lower-cost earth-based experiments that include drop towers and parabolic flights. With the advent of the International Space Station, relevant microgravity research was undertaken in the field of metal solidification science, and limited studies of brazing and soldering were undertaken; however, no welds have ever been on the Space Station. Therefore, it has been almost 40 years since a weld was made in space. Much like terrestrial construction and manufacturing industries, welding, joining, and allied processes will be enabling technologies for In-space Assembly and Manufacturing (ISAM) in the nascent “Space Economy”, a sector that is expected to approach a value of 10^12 USD within the next decade. It is critical that the welding and joining research community, along with the welding industry, engages the space industry to advance the understanding of those critical manufacturing processes which must be evaluated and matured in the extreme environments of space. Such environments include variable gravity (microgravity in low earth orbit, 0.17 gravity on the lunar surface, and 0.38 gravity on the martian surface), reduced pressure (extreme vacuum in space and the lunar surface to a predominantly CO2 atmosphere on Mars), and extreme temperatures (between 40 and 400 K). Past experiments and analyses are reviewed to suggest requirements that the welding and joining community should target to make strides on closing the current space welding gaps. Efforts to continue welding in space are currently underway at NASA in conjunction with academia and industry. Those are explored along with future agency goals which are seen as opportunities to engage the welding community on this historic effort.

in-space assembly and manufacturing↗

Measuring the Wear and Abrasive Resistance of Air Plasma Sprayed Aluminum Oxide for Lunar Exploration

Lunar regolith, especially finer dust particles traveling at high velocities, can cause significant wear and abrasive damage to structural components that ensure a prolongated presence on the surface of the Moon. With the absence of an atmosphere and lower gravity than on Earth, regolith particles maintain high velocities at large distances from where they were generated, for example next to lunar landers. Wear-resistant ceramic and ceramic composite materials can improve the durability of spacecraft components during long missions on the Moon’s surface. Aluminum oxide coatings are lightweight, have multifunctional properties, and have high strength including high hardness and wear resistance. These properties can help improve the durability of structures used in space exploration. Air plasma sprayed (APS) aluminum oxide coatings have demonstrated the potential to protect critical structures. This study investigated the abrasive wear resistance of APS aluminum oxide coatings via Taber abrasion experiments. Taber abrasion offers the advantage of quantifying the abrasive wear behavior of particles with different shapes on a surface. In this work, an abrasive wheel made of silicon carbide was utilized to evaluate wear properties of specimens progressively over 5000 cycles. This experiment focused on testing two series of specimens to determine whether a bond coat composed of nickel, chromium, aluminum, and yttrium (NiCrAlY) improved the protective behavior of the APS aluminum oxide coating. The specimens varied in topcoat thickness and were made with and without an approximately 100 µm bond coat layer. The mass of the specimens was measured at 400 cycles, 800 cycles, 3800 cycles, and 5000 cycles. Increasing thickness was found to result in higher wear for samples with and without a bond coat. Increased mass loss in samples with a bond coat was observed indicating a need for further studies on the overall impact of the use of a bond coat on the protective behavior of the coatings. To continue designing wear resistant coatings for structural protection in space missions, the multifunctional properties of the APS aluminum oxide coating will be studied. Future experiments will determine whether the APS aluminum oxide coating can protect the structures from other aspects of the harsh space environment, such as extreme temperature variations and ionizing radiation.

aluminum oxide↗

Durability of Geopolymer Lunar Concrete From Exposure in Low Earth Orbit

Constructing infrastructure autonomously with concrete materials through additive manufacturing techniques on the lunar surface is a feasible option. The environmental and exposure conditions that the lunar concrete material will undergo are more extreme than on Earth and studying the durability aspect is important to scaling up the implementation of such materials. Conditions that the material will be exposed to include a hard vacuum, extreme temperatures, and ultraviolet radiation. To that end, geopolymer lunar concrete and ordinary portland cement paste samples were placed outside the International Space Station (ISS) for an approximate six-month exposure period. The samples were part of the 15th Materials International Space Station Experiment (MISSE-15) mission and were mounted in the zenith direction. After the exposure time, results for the samples exhibited discoloration, microstructural cracking, and an overall reduction in volume compared to data collected beforehand. The intent of this work was to characterize geopolymer lunar concrete durability in terms of the lunar environmental conditions in LEO and potential exposure scenarios from a simulated subscale rocket engine plume. To understand the durability of samples in space environment conditions, samples were placed outside the International Space Station (ISS) for a six-month period on the MISSE-FF. Additionally, to test the material's durability if implemented for use in a landing pad, samples were created for an experiment that mimics the exposure of the material to a rocket engine associated with the human lander system. This work is essential to progressing and scaling up geopolymer lunar concrete for implementation as the material's durability is assessed.

Peter J Collins↗

Heat-Exchange Driven Aircraft for Low Altitude and Surface Exploration of Venus: Phase 1 Study Final Report

Exploration of Venus below its clouds has long been impaired by the planet’s massive CO2 atmosphere, corrosive trace gases, and high opacity. Except for a few narrow spectral windows, the 20 km thick global cloud cover blocks light over the entirety of the ultraviolet through thermal infrared spectrum, impeding orbital studies of the surface and lower portion of the atmosphere. In addition to the cloud opacity, Rayleigh scattering through 80 bars of CO 2 in the lower 40 km of the atmosphere results in a Rayleigh scattering depth between 25 and1 in the visible through near infrared portion of the spectrum. That optically thick scattering, combined with the uniform angular distribution of the illumination provided by the highly diffusing clouds overhead greatly reduces even very large surface albedo contrasts (Crisp, pers. Comm.). To date, the surface has only been mapped via synthetic aperture radar by the Magellan mission at scales of 120 to 300 m/pixel. In addition to contributing to the difficulty of performing studies of the surface from orbit, the extreme temperatures and pressures at the surface also create a challenging environment to utilize a lander for exploration. The longest-lived lander on Venus’ surface survived for 2 hours. Hence, limited access to observe the surface and lower atmosphere of Venus arguably puts the surface and lower atmosphere of Venus as one of the least explored regions of the inner Solar System.

NIAC Phase I↗

Next Generation Batteries for Electric Aviation and Space

Energy storage plays a critical part in the success of future NASA missions that desire batteries with higher energy density, higher power, and most critically improved safety. These performance requirements stretch beyond that of electric automobile markets and are required for enabling widespread adoption of electric aviation. One approach to improve the safety and energy is the transition to non-volatile solid-state electrolytes (SSE) which promise many advantages over traditional flammable liquid electrolytes and may also be an enabling technology for next generation chemistries such as lithium-sulfur (Li-S). However, significant manufacturing challenges must be overcome before the adoption of such technology. This study will discuss the development of solid electrolytes specifically designed to meet future NASA electric aviation targets with densified thicknesses between 20-30 microns derived using solvent processing techniques. Films were produced 10-15 times thinner than comparable bulk cold pressed powder electrolytes and achieved thicknesses comparable to commercial polyolefin separators (25 micron) used in commercial liquid containing lithium-ion cells. Furthermore, design and development of novel cathode composites through integration of experiment and a particle dynamics model will be discussed. Beyond aeronautics, unique challenges and requirements exist for energy storage for space applications, which can cover extreme temperatures and material scarcity for in-situ derived materials. Additionally, this talk will briefly cover the need and development of lunar and Martian derived electrode materials for in-situ manufacturing of energy storage devices.

Batteries↗

Analyses of the MISSE 9-15 Polymers and Composites Experiment 1-4 (PCE 1-4) Contamination Samples

Spacecraft in low Earth orbit (LEO) are subjected to harsh environmental conditions, including radiation (cosmic rays, ultraviolet (UV), x-ray and charged particle radiation), micrometeoroids and orbital debris, temperature extremes, thermal cycling, and atomic oxygen (AO). These environmental exposures can result in erosion, embrittlement and optical property degradation of susceptible materials threatening spacecraft performance and durability. To increase our understanding of environmental effects such as AO erosion and radiation induced embrittlement of spacecraft materials, NASA Glenn Research Center developed a series of experiments that were flown as part of the Materials International Space Station Experiment (MISSE) missions on the exterior of the International Space Station (ISS). Recently, four Glenn experiments with 365 flight samples were flown on ISS’s MISSE-Flight Facility (MISSE-FF). These experiments are the Polymers and Composites Experiment-1 (PCE-1) flown as part of the MISSE-9 mission, the PCE-2 flown as part of the MISSE-10 mission, the PCE-3 flown as part of the MISSE-12 and MISSE-15 missions, and the PCE-4 flown as part of the MISSE-13 mission. Each of these experiments included passive contamination witness samples in each flight direction for post-flight molecular contamination analyses. A total of 13 contamination flight samples were flown. The post-flight analyses of the PCE 1-4 contamination samples include X-ray Photoelectron Spectroscopy (XPS) analyses (surface and ion sputter depth analyses) and optical properties (total reflectance, total transmittance and solar absorptance). This paper provides results of post-flight analyses of the PCE 1-4 contamination samples and their corresponding control samples. Knowledge of on-orbit contamination is important for the PCE 1-4 flight data interpretation.

Atomic Oxygen↗