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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Extreme Environments Solar Power Project Enabling Solar Array Power To The Outer Planets

NASA missions such as DAWN and JUNO, as well as the planned Europa Clipper mission, rely on solar power despite their destination's extreme distance from the Sun and the high radiation environment typically encountered. This reliance on off-the-shelf state of the art solar cells has impacted mission design and ultimate performance, as solar cells designed for 1AU space applications suffer from low intensity, low temperature (LILT) performance effects and limited radiation tolerance has required additional shielding or overdesign in order to maintain EOL performance. While reasons for the performance degradation are reasonably well understood and solutions have been proposed, the lack of a continuous mission pull for improved performance has made a dedicated project to address these issues unpractical in the past. However, with NASA embarking on the Europa Clipper mission in the next decade and a recognition that improvements to radiation tolerance positively impact all space missions; NASA's Space Technology Mission Directorate has initiated a project to develop advanced solar cells that are more efficient under LILT conditions and solar array concepts, such as concentrator systems, that improve overall performance under both LILT and high radiation conditions.

McNatt, Jeremiah↗
NASA NTRS1985

Microbial ecology of extreme environments: Antarctic yeasts and growth in substrate-limited habitats

The high, dry valleys of the Ross Desert of Antarctic, characterized by extremely low temperatures, aridity and a depauperate biota, are used as an analog of the postulated extreme climates of other planetary bodies of the Solar System to test the hypothesis that if life could be supported by Ross, it might be possible where similar conditions prevail. The previously considered sterility of the Ross Desert soil ecosystem has yielded up an indigenous yeast, Cryptoccus vishniacci, which is able to resist the extremes of cold, wet and dry freezing, and long arid periods, while making minimal nutritional demands on the soil.

Vishniac, H. S.↗
NASA NTRSDate not supplied

Materials for Extreme Environments: Paving the Way for Lunar Exploration

As humanity expands its ventures into lunar and planetary exploration, the demand intensifies for resilient materials capable of enduring extreme environmental and service conditions. The Moon’s surface presents numerous challenges, including ultra-high vacuum exposure, temperature extremes and intense radiation. Additionally, lunar regolith poses a significant threat to component durability and reusability due to its abrasive nature. Lunar dust particles scoring, adhering, or embedding into surfaces and within device-confined geometries, such as bearings, drive mechanisms and connectors, can cause premature component wear or failure. Furthermore, the interaction between the rocket plume and the surface during vehicle landings and ascents creates severe erosive conditions near critical vehicle components and adjacent infrastructure. A key barrier hindering materials discovery for lunar dust tolerant applications is a lack of standard laboratory methods to evaluate material properties and performance under representative operating conditions. A case will be presented for research activities supporting identification, processing and characterization of candidate materials in conjunction with innovations in standardized testing and qualification. Results will highlight current and emerging test methods for simulating lunar dust exposure and component degradation, paving the way for a new generation of robust materials and coatings for space exploration.

Lunar dust↗
NASA NTRS2006

Robust, Thin Optical Films for Extreme Environments

The environment of space presents scientists and engineers with the challenges of a harsh, unforgiving laboratory in which to conduct their scientific research. Solar astronomy and X-ray astronomy are two of the more challenging areas into which NASA scientists delve, as the optics for this high-tech work must be extremely sensitive and accurate, yet also be able to withstand the battering dished out by radiation, extreme temperature swings, and flying debris. Recent NASA work on this rugged equipment has led to the development of a strong, thin film for both space and laboratory use.

Source record↗
NASA NTRS1982

A commentary on solid lubricants and wear resistant solids for use in extreme environments

The need for high temperature tribological coatings and self-lubricating materials in advanced technology is discussed. A qualitative model for the mechanism of solid lubrication is proposed. The model is based upon microscopic observations of the dynamics of third-body solids in lubricated contacts. In this model, the rheology of plastic flow is suggested as a more general criterion for predicting the lubricating potential of a solid material than, for example, a specific crystal structure. Some examples of layer-lattice and nonlayer-lattice solids that lubricate by virtue of their extreme plasticity, film coherence, and adhesion to the lubricated metal are described. Circumstantial evidence for the model is presented for low shear-strength solids at room temperature and for solids such as calcium fluoride that become lubricative only when their brittle-to-ductile transition temperature is exceeded. Some materials considerations in the selection of hard-coat materials for wear control are also presented.

Sliney, H. E.↗
NASA NTRS2007

Radiation Hardened Electronics for Extreme Environments

The Radiation Hardened Electronics for Space Environments (RHESE) project consists of a series of tasks designed to develop and mature a broad spectrum of radiation hardened and low temperature electronics technologies. Three approaches are being taken to address radiation hardening: improved material hardness, design techniques to improve radiation tolerance, and software methods to improve radiation tolerance. Within these approaches various technology products are being addressed including Field Programmable Gate Arrays (FPGA), Field Programmable Analog Arrays (FPAA), MEMS Serial Processors, Reconfigurable Processors, and Parallel Processors. In addition to radiation hardening, low temperature extremes are addressed with a focus on material and design approaches.

Keys, Andrew S.↗
NASA NTRS2021

Practical SiC JFET-R Analog Integrated Circuit Design for Extreme Environment Applications

Silicon carbide (SiC) junction field effect transistor and SiC resistor (SiC JFET-R) integrated circuits(ICs) have uniquely demonstrated prolonged operation above 450 °C that promises significant operational improvements to a variety of NASA missions. However, the SiC epiwafers used to fabricate these ICs suffer from epi-growth process immaturity that imparts large and systematic spreads in JFET threshold voltages as a function of the device distance from the center on the wafer. Furthermore, the unprecedently wide range of intended application operating temperatures (in many cases over 600 °C wide) imparts as much as 5-fold change in JFET bias currents. This Technical Memorandum documents methods by which both temperature and radius associated JFET electrical parameter variances can be adequately eliminated, or even exploited in JFET-R circuit designs. Full analog circuit examples, including operational amplifiers, and SPICE simulations across experimentally documented SiC JFET parameter extremes are given to illustrate the efficacy of these methods. The reader may use the examples in this memorandum as either an end point, to get a desired analog signal conditioning design into hardware implemented in SiC JFET-R ICs, or as a basis point from which to derive further improvement.

Michael J Krasowski↗
NASA NTRSDate not supplied

Advancement of Extreme Environment Additively Manufactured Alloys for Next Generation Space Propulsion Applications

The National Aeronautics and Space Administration (NASA) has been involved in the development and maturation of metal additive manufacturing (AM) for space applications since the late 2000’s. Several efforts focused on the understanding of AM processes through material characterization and testing, standards development, component fabrication, and infusion into propulsion development and flight applications. NASA matured commonly used aerospace alloys from various alloy families (Nickel, Copper, Stainless and Steel, Aluminum, and Titanium-based) through detailed AM process and heat treatment characterization, in addition to mechanical and thermophysical testing. While these alloys are actively used in many propulsion applications, there is a need for ongoing AM optimized alloys using integrated computational materials engineering (ICME) and process development for high performance applications. The applications targeted are liquid rocket engines; advanced propulsion systems; and in-space propulsion with high heat fluxes, high pressure, and/or that use propellants that can degrade alloys (e.g., hydrogen). This paper highlights the characterization and physical properties of the more common AM alloys using laser powder bed fusion (L-PBF) and laser powder directed energy deposition (LP-DED) processes. Additionally, this paper discusses some of the ongoing novel alloy development and maturation using AM for use in these harsh environments, such as GRCop-42, GRCop-84, NASA HR-1, GRX-810, and C-103. The results from these processes demonstrated that AM could enable rapid development and ongoing efforts for optimized alloys using ICME, yielding higher performances. These alloys have undergone modeling, fundamental metallurgical evaluations, heat treatment studies, detailed microstructure characterization, and mechanical testing campaigns. This, combined with direct application-specific component fabrication and hot-fire testing, enabled the increase of the Technology Readiness Level (TRL) through high duty-cycle testing. A background and overview of these novel AM-enabled alloys and AM processing developments including metallurgical and mechanical property studies is presented here. The latest advancement in the parallel component development and hot-fire testing and future developments for these alloys is also discussed.

Additive Manufacturing↗
NASA NTRSDate not supplied

Advancement of Extreme Environment Additively Manufactured Alloys for Next Generation Space Propulsion Applications

The National Aeronautics and Space Administration (NASA) has been involved in the development and maturation of metal additive manufacturing (AM) for space applications since the late 2000’s. Several efforts focused on the understanding of AM processes through material characterization and testing, standards development, component fabrication, and infusion into propulsion development and flight applications. NASA matured commonly used aerospace alloys from various alloy families (Nickel, Copper, Stainless and Steel, Aluminum, and Titanium-based) through detailed AM process and heat treatment characterization, in addition to mechanical and thermophysical testing. While these alloys are actively used in many propulsion applications, there is a need for ongoing AM optimized alloys using integrated computational materials engineering (ICME) and process development for high performance applications. The applications targeted are liquid rocket engines; advanced propulsion systems; and in-space propulsion with high heat fluxes, high pressure, and/or that use propellants that can degrade alloys (e.g., hydrogen). This paper highlights the characterization and physical properties of the more common AM alloys using laser powder bed fusion (L-PBF) and laser powder directed energy deposition (LP-DED) processes. Additionally, this paper discusses some of the ongoing novel alloy development and maturation using AM for use in these harsh environments, such as GRCop42, GRCop-84, NASA HR-1, GRX-810, and C-103. The results from these processes demonstrated that AM could enable rapid development and ongoing efforts for optimized alloys using ICME, yielding higher performances. These alloys have undergone modeling, fundamental metallurgical evaluations, heat treatment studies, detailed microstructure characterization, and mechanical testing campaigns. This, combined with direct application-specific component fabrication and hot-fire testing, enabled the increase of the Technology Readiness Level (TRL) through high duty-cycle testing. A background and overview of these novel AM-enabled alloys and AM processing developments including metallurgical and mechanical property studies is presented here. The latest advancement in the parallel component development and hot-fire testing and future developments for these alloys is also discussed.

Additive Manufacturing↗
NASA NTRS1967

Metal flame spray coating protects electrical cables in extreme environment

Metal flame spray coating prevents EMF measurement error in sheathed instrumentation cables which are externally attached to cylinders which were cooled on the inside, but exposed to gamma radiation on the outside. The coating provides a thermoconductive path for radiation induced high temperatures within the cables.

Brady, R. D.↗
NASA NTRS1981

Microbial ecology of extreme environments: Antarctic dry valley yeasts and growth in substrate limited habitats

The multiple stresses temperature, moisture, and for chemoheterotrophs, sources of carbon and energy of the Dry Valley Antarctica soils allow at best depauperate communities, low in species diversity and population density. The nature of community structure, the operation of biogeochemical cycles, the evolution and mechanisms of adaptation to this habitat are of interest in informing speculations upon life on other planets as well as in modeling the limits of gene life. Yeasts of the Cryptococcus vishniacil complex (Basidiobiastomycetes) are investigated, as the only known indigenes of the most hostile, lichen free, parts of the Dry Valleys. Methods were developed for isolating these yeasts (methods which do not exclude the recovery of other microbiota). The definition of the complex was refined and the importance of nitrogen sources was established as well as substrate competition in fitness to the Dry Valley habitats.

Vishniac, H. S.↗
NASA NTRS1982

Microbial ecology of extreme environments: Antarctic dry valley yeasts and growth in substrate-limited habitats

The success of the Antarctic Dry Valley yeasts presumeably results from adaptations to multiple stresses, to low temperatures and substrate-limitation as well as prolonged resting periods enforced by low water availability. Previous investigations have suggested that the crucial stress is substrate limitation. Specific adaptations may be pinpointed by comparing the physiology of the Cryptococcus vishniacii complex, the yeasts of the Tyrol Valley, with their congeners from other habitats. Progress was made in methods of isolation and definition of ecological niches, in the design of experiments in competition for limited substrate, and in establishing the relationships of the Cryptococcus vishniacii complex with other yeasts. In the course of investigating relationships, a new method for 25SrRNA homology was developed. For the first time it appears that 25SrRNA homology may reflect parallel or convergent evolution.

Vishniac, H. S.↗
NASA NTRS1994

Planetary stations and Abyssal Benthic Laboratories: An overview of parallel approaches for long-term investigation in extreme environments

In spite of the apparent great differences between deep ocean and space environment, significant similarities can be recognized when considering the possible solutions and technologies enabling the development of remote automatic stations supporting the execution of scientific activities. In this sense it is believed that mutual benefits shall be derived from the exchange of experiences and results between people and organizations involved in research and engineering activities for hostile environments, such as space, deep sea, and polar areas. A significant example of possible technology transfer and common systematic approach is given, which describes in some detail how the solutions and the enabling technologies identified for an Abyssal Benthic Laboratory can be applied for the case of a lunar or planetary station.

Dipippo, S.↗