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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 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

Safety research of insulating materials of cable for nuclear power generating station

The polymers PE, EPR, PVC, Neoprene, CSP, CLPE, EP and other similar substances are frequently used as insulation and protective covering for cables used in nuclear power generating stations. In order to test these materials for flame retardation, environmental resistance, and cable specifications, they were given the cable normal test, flame test, chemical tests, and subjected to design analysis and loss of coolant accident tests. Material was collected on spark tests and actual experience standards were established through these contributions and technology was accumulated.

Lee, C. K.↗
NASA NTRS1965

Multiple test chamber exposes materials to various environments

Multiple compartment test chamber exposes several material specimens to various environmental conditions for prolonged periods. The specimens are individually mounted in chamber compartments, rotated to various positions, and measured through optical windows to determine progressive changes in the material properties.

Johnston, R. L.↗
NASA NTRS1982

Turbine engine materials durability research

High temperature environmental attack of dollar intensive turbine components reduces turbine efficiency and can limit life. The mechanisms of alloy and coating attack and the effects of interaction with the environment on mechanical behavior. This base of understanding provides the foundation for developing life prediction methods and identifying strategies for controlling attack. Subjects discussed in detail include oxidation and new developments in thermal barrier coating research.

S. R. Levine↗
NASA NTRS1991

Elevated temperature cracking of RSP aluminum alloy 8009 - Characterization of the environmental influence

Degradation of the material properties of the Al alloy is examined to determine the effects of moist air and predissolved hydrogen on elevated-temperature fatigue and fracture resistance. Experiments are conducted at 175 C in both moist air and high vacuum with as-processed specimens and specimens that are vacuum-heat-treated. Fracture mechanics characterizations are made for initiation and propagation fracture toughnesses during rising load, fatigue-crack propagation kinetics, and sustained-load crack-growth rates. Time-dependent embrittlement at intermediate temperatures is identified in both plate and extrusion samples of the Al-Fe-Si-V alloy 8009. Intermediate temperature cracking is found to be the same for each case in both vacuum and moist air, and the vacuum heat treatment does not significantly affect the results.

Porr, William C., Jr.↗
NASA NTRS2019

Compositional and Microstructural Effects in the Protection of SiC Components in Water Vapor

Greater gas turbine engine efficiency is a major goal in aeronautics research often pursued through increased engine operating temperatures. However, it is necessary to replace the current hot-stage alloy components with more thermally robust parts, such as promising Silicon-based ceramics and composites. Unfortunately, these materials are still susceptible to the effects of oxidation, water vapor, and (Calcium-Magnesium-Alumino-Silicate) CMAS interaction, among other issues at high temperature. To mitigate these effects, environmental barrier coating (EBC) materials are employed to help control the rate of degradation to the underlying composite. Often, a thermally grown oxide (TGO) layer forms between the EBC and the composite which can act as a point of failure. The current study focuses on the combined effects of water vapor, composite composition, and microstructure in TGO formation on protected and unprotected SiC samples which have been produced under different processing conditions.

Kowalski, Benjamin↗
NASA NTRS1993

Research and test facilities

A description is given of each of the following Langley research and test facilities: 0.3-Meter Transonic Cryogenic Tunnel, 7-by 10-Foot High Speed Tunnel, 8-Foot Transonic Pressure Tunnel, 13-Inch Magnetic Suspension & Balance System, 14-by 22-Foot Subsonic Tunnel, 16-Foot Transonic Tunnel, 16-by 24-Inch Water Tunnel, 20-Foot Vertical Spin Tunnel, 30-by 60-Foot Wind Tunnel, Advanced Civil Transport Simulator (ACTS), Advanced Technology Research Laboratory, Aerospace Controls Research Laboratory (ACRL), Aerothermal Loads Complex, Aircraft Landing Dynamics Facility (ALDF), Avionics Integration Research Laboratory, Basic Aerodynamics Research Tunnel (BART), Compact Range Test Facility, Differential Maneuvering Simulator (DMS), Enhanced/Synthetic Vision & Spatial Displays Laboratory, Experimental Test Range (ETR) Flight Research Facility, General Aviation Simulator (GAS), High Intensity Radiated Fields Facility, Human Engineering Methods Laboratory, Hypersonic Facilities Complex, Impact Dynamics Research Facility, Jet Noise Laboratory & Anechoic Jet Facility, Light Alloy Laboratory, Low Frequency Antenna Test Facility, Low Turbulence Pressure Tunnel, Mechanics of Metals Laboratory, National Transonic Facility (NTF), NDE Research Laboratory, Polymers & Composites Laboratory, Pyrotechnic Test Facility, Quiet Flow Facility, Robotics Facilities, Scientific Visualization System, Scramjet Test Complex, Space Materials Research Laboratory, Space Simulation & Environmental Test Complex, Structural Dynamics Research Laboratory, Structural Dynamics Test Beds, Structures & Materials Research Laboratory, Supersonic Low Disturbance Pilot Tunnel, Thermal Acoustic Fatigue Apparatus (TAFA), Transonic Dynamics Tunnel (TDT), Transport Systems Research Vehicle, Unitary Plan Wind Tunnel, and the Visual Motion Simulator (VMS).

Source record↗
NASA NTRS2005

NASA Hydrogen Peroxide Propellant Hazards Technical Manual

The Fire, Explosion, Compatibility and Safety Hazards of Hydrogen Peroxide NASA technical manual was developed at the NASA Johnson Space Center White Sands Test Facility. NASA Technical Memorandum TM-2004-213151 covers topics concerning high concentration hydrogen peroxide including fire and explosion hazards, material and fluid reactivity, materials selection information, personnel and environmental hazards, physical and chemical properties, analytical spectroscopy, specifications, analytical methods, and material compatibility data. A summary of hydrogen peroxide-related accidents, incidents, dose calls, mishaps and lessons learned is included. The manual draws from art extensive literature base and includes recent applicable regulatory compliance documentation. The manual may be obtained by United States government agencies from NASA Johnson Space Center and used as a reference source for hazards and safe handling of hydrogen peroxide.

Baker, David L.↗
NASA NTRS1992

Synergistic effects of ultraviolet radiation, thermal cycling, and atomic oxygen on altered and coated Kapton surfaces

The photovoltaic (PV) power system for Space Station Freedom (SSF) uses solar array blankets which provide structural support for the solar cells and house the electrical interconnections. In the low Earth orbital (LEO) environment where SSF will be located, surfaces will be exposed to potentially damaging environmental conditions including solar ultraviolet (UV) radiation, thermal cycling, and atomic oxygen. It is necessary to use ground based tests to determine how these environmental conditions would affect the mass loss and optical properties of candidate SSF blanket materials. Silicone containing, silicone coated, and SiO(x) coated polyimide film materials were exposed to simulated LEO environmental conditions to determine there durability and whether the environmental conditions of UV, thermal cycling and oxygen atoms act synergistically on these materials. A candidate PV blanket material called AOR Kapton, a polysiloxane polyimide cast from a solution mixture, shows an improvement in durability to oxygen atoms erosion after exposure to UV radiation or thermal cycling combined with UV radiation. This may indicate that the environmental conditions react synergistically with this material, and the damage predicted by exposure to atomic oxygen alone is more severe than that which would occur in LEO where atomic oxygen, thermal cycling and UV radiation are present together.

Dever, Joyce A.↗
NASA NTRS1992

Synergistic effects of ultraviolet radiation, thermal cycling and atomic oxygen on altered and coated Kapton surfaces

The photovoltaic (PV) power system for Space Station Freedom (SSF) uses solar array blankets which provide structural support for the solar cells and house the electrical interconnections. In the low earth orbital (LEO) environment where SSF will be located, surfaces will be exposed to potentially damaging environmental conditions including solar ultraviolet (UV) radiation, thermal cycling, and atomic oxygen. It is necessary to use ground based tests to determine how these environmental conditions would affect the mass loss and optical properties of candidate SSF blanket materials. Silicone containing, silicone coated, and SiO(x) coated polyimide film materials were exposed to simulated LEO environmental conditions to determine their durability and whether the environmental conditions of UV, thermal cycling and oxygen atoms act synergistically on these materials. A candidate PV blanket material called AOR Kapton, a polysiloxane polyimide cast from a solution mixture, shows an improvement in durability to oxygen atoms erosion after exposure to UV radiation or thermal cycling combined with UV radiation. This may indicate that the environmental conditions react synergistically with this material, and the damage predicted by exposure to atomic oxygen alone is more severe than that which would occur in LEO where atomic oxygen, thermal cycling and UV radiation are present together.

Dever, Joyce A.↗
NASA NTRS1997

Habitats and Surface Construction Technology and Development Roadmap

The vision of the technology and development teams at NASA Ames and Johnson Research Centers is to provide the capability for automated delivery and emplacement of habitats and surface facilities. The benefits of the program are as follows: Composites and Inflatables: 30-50% (goal) lighter than Al Hard Structures; Capability for Increased Habitable Volume, Launch Efficiency; Long Term Growth Potential; and Supports initiation of commercial and industrial expansion. Key Habitats and Surface Construction (H&SC) technology issues are: Habitat Shell Structural Materials; Seals and Mechanisms; Construction and Assembly: Automated Pro-Deploy Construction Systems; ISRU Soil/Construction Equipment: Lightweight and Lower Power Needs; Radiation Protection (Health and Human Performance Tech.); Life Support System (Regenerative Life Support System Tech.); Human Physiology of Long Duration Space Flight (Health and Human Performance Tech.); and Human Psychology of Long Duration Space Flight (Health and Human Performance Tech.) What is being done regarding these issues?: Use of composite materials for X-38 CRV, RLV, etc.; TransHAB inflatable habitat design/development; Japanese corporations working on ISRU-derived construction processes. What needs to be done for the 2004 Go Decision?: Characterize Mars Environmental Conditions: Civil Engineering, Material Durability, etc.; Determine Credibility of Inflatable Structures for Human Habitation; and Determine Seal Technology for Mechanisms and Hatches, Life Cycle, and Durability. An overview encompassing all of the issues above is presented.

Marc Cohen↗
NASA NTRS1994

Physical and mechanical metallurgy of NiAl

Considerable research has been performed on NiAl over the last decade, with an exponential increase in effort occurring over the last few years. This is due to interest in this material for electronic, catalytic, coating and especially high-temperature structural applications. This report uses this wealth of new information to develop a complete description of the properties and processing of NiAl and NiAl-based materials. Emphasis is placed on the controlling fracture and deformation mechanisms of single and polycrystalline NiAl and its alloys over the entire range of temperatures for which data are available. Creep, fatigue, and environmental resistance of this material are discussed. In addition, issues surrounding alloy design, development of NiAl-based composites, and materials processing are addressed.

Noebe, Ronald D.↗
NASA NTRS2022

Guatemala and Panama Urban Development: Evaluating the Effects of Urban Expansion on Social and Environmental Vulnerability in Guatemala and Panama

Central America is experiencing rapid and unregulated urban expansion, which is contributing to an increase in socioeconomic and environmental risks including inequities in infrastructure and housing accessibility, biodiversity loss, vulnerability to natural disasters, and negative health outcomes. NASA DEVELOP, in partnership with NASA SERVIR, Sistema de la Integración Centroamericana (SICA), Secretariat of Central American Social Integration (SISCA), Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ), and Centro de Coordinación para la Prevención de los Desastres en América Central y República Dominicana (CEPRENEDAC), examined changes in urban extent, characterized roofing material type, and analyzed vulnerability within urban areas in two Central American cities, Guatemala City and Panama City. The team used land cover imagery from Landsat 5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper Plus (ETM+), Landsat 8 Operational Land Imager (OLI), and Landsat 9 OLI-2 to map urban extent, and surface reflectance data from Maxar Worldview to identify roofing material types. Socioeconomic and environmental data were used to assess vulnerability. Results depict how the two cities have expanded from 2000 to present day and highlight areas of greatest vulnerability within each urban area. The supervised classification of roofing materials performed well but could be improved with a few enhancements. Findings can help partner organizations improve monitoring of urbanization and inform their planning and decision-making while prioritizing disaster prevention, public health, and environmental integrity. Additionally, these case studies can be used to inform future, similar work elsewhere in Central America to aid in understanding urbanization and its associated challenges.

Jennifer Ruiz↗
NASA NTRS1980

Agreement for NASA/OAST - USAF/AFSC space interdependency on spacecraft environment interaction

A joint AF/NASA comprehensive program on spacecraft environment interactions consists of combined contractual and in house efforts aimed at understanding spacecraft environment ineraction phenomena and relating ground test results to space conditions. Activities include: (1) a concerted effort to identify project related environmental interactions; (2) a materials investigation to measure the basic properties of materials and develop or modify materials as needed; and (3) a ground simulation investigation to evaluate basic plasma interaction phenomena and provide inputs to the analytical modeling investigation. Systems performance is evaluated by both ground tests and analysis. There is an environmental impact investigation to determine the effect of future large spacecraft on the charged particle environment. Space flight investigations are planned to verify the results. The products of this program are test standards and design guidelines which summarize the technology, specify test criteria, and provide techniques to minimize or eliminate system interactions with the charged particle environment.

Pike, C. P.↗
NASA NTRSDate not supplied

Space Environmental Effects on Additively Manufactured (AM) Parts on MISSE-9/10

The Materials on International Space Station Experiment (MISSE) experiments have made a continuous presence on the ISS and allowed for testing of performance and durability of materials exposed to the Low Earth Orbit (LEO) space environment. Additive Manufacturing (AM) has been included on several MISSE flights, and many companies (Made in Space and Stratasys) and NASA centers wanted to test various AM material samples. The goal of studying Space Environmental Effects on AM Parts with MISSE 9/10 was to fly promising metal and polymer AM material samples (dogbones) that could have future manufacturing capabilities in space and conduct post-flight analysis of these materials via mechanical and optical properties. On these flights, MISSE-9 contained three Inconel and 12 polymer samples and MISSE-10 included three Inconel and 16 polymer samples. Before flying to the ISS, all the samples underwent thermal vacuum bakeout (at 60°C for 24 hours and 10-6 torr). After bakeout, control and flight experiments were weighed, and optical properties were taken. Optical properties such as solar absorptance and infrared emittance were taken on the control samples and the flight samples (preflight and postflight). To understand more about the mechanical properties of the AM samples, tensile testing was conducted on the samples to determine the yield and ultimate tensile strength of the dogbone samples against the control. Lastly, the torque on the fasteners securing the dogbone samples were loosened and measured using a torque wrench, and they were compared to their preflight torque specification required. Optical properties and masses were recorded before flight, and the postflight results were recorded and collected in June 2022 to study the effects. With the postflight analysis, NASA engineers can now better characterize how UV radiation and thermal cycling affect the material properties.

Materials on International Space Station Experimen↗
NASA NTRS2013

Calcium-Magnesium-Aluminosilicate (CMAS) Reactions and Degradation Mechanisms of Advanced Environmental Barrier Coatings

The thermochemical reactions between calcium-magnesium-aluminosilicate- (CMAS-) based road sand and several advanced turbine engine environmental barrier coating (EBC) materials were studied. The phase stability, reaction kinetics and degradation mechanisms of rare earth (RE)-silicates Yb2SiO5, Y2Si2O7, and RE-oxide doped HfO2 and ZrO2 under the CMAS infiltration condition at 1500 C were investigated, and the microstructure and phase characteristics of CMAS-EBC specimens were examined using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Experimental results showed that the CMAS dissolved RE-silicates to form crystalline, highly non-stoichiometric apatite phases, and in particular attacking the silicate grain boundaries. Cross-section images show that the CMAS reacted with specimens and deeply penetrated into the EBC grain boundaries and formed extensive low-melting eutectic phases, causing grain boundary recession with increasing testing time in the silicate materials. The preliminary results also showed that CMAS reactions also formed low melting grain boundary phases in the higher concentration RE-oxide doped HfO2 systems. The effect of the test temperature on CMAS reactions of the EBC materials will also be discussed. The faster diffusion exhibited by apatite and RE-doped oxide phases and the formation of extensive grain boundary low-melting phases may limit the CMAS resistance of some of the environmental barrier coatings at high temperatures.

Ahlborg, Nadia L.↗
NASA NTRS1993

The importance of environmental conditions in reflectance spectroscopy of laboratory analogs for Mars surface materials

Reflectance spectra are presented here for a variety of particulate, ferric-containing analogs to Martian soil (Fe(3+)-doped smectites and palagonites) to facilitate interpretation of remotely acquired spectra. The analog spectra were measured under differing environmental conditions to evaluate the influence of exposure history on water content and absorption features due to H2O in these samples. Each of these materials contains structural OH bonded to metal cations, adsorbed H2O, and bound H2O (either in a glass, structural site, or bound to a cation). Previous experiments involving a variety of Mars analogs have shown that the 3 micron H2O band in spectra of palagonites is more resistant to drying than the 3 micron H2O band in spectra of montmorillonites. Other experiments have shown that spectra of ferrihydrite and montmorillonites doped with ferric sulfate also contain sufficient bound H2O to retain a strong 3 micron band under dry conditions. Once the effects of the environment on bound water in clays, oxides, and salts are better understood, the hydration bands measured via reflectance spectroscopy can be used to gain information about the chemical composition and moisture content of real soil systems. Such information would be especially useful in interpreting observations of Mars where subtle spatial variations in the strengths of metal-OH and H2O absorptions have been observed in telescopic and ISM spectra. We measured bidirectional reflectance spectra of several Mars soil analogs under controlled environmental conditions to assess the effects of moisture content on the metal-OH and H2O absorptions. The samples analyzed include chemically altered montmorillonites, ferrihydrite. and palagonites from Hawaii and Iceland. Procedures for preparation of the cation-exchanged montmorillonites, ferric-salt doped montmorillonites, and ferric oxyhydroxides are described in detail elsewhere.

Bishop, J.↗