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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 1,765 records · Page 98
All sourcesNASA NTRSDOE OSTI
NASA NTRS1998

Orbital Debris Impact Damage to Reusable Launch Vehicles

In an effort by the National Aeronautics and Space Administration (NASA), hypervelocity impact tests were performed on thermal protection systems (TPS) applied on the external surfaces of reusable launch vehicles (RLV) to determine the potential damage from orbital debris impacts. Three TPS types were tested, bonded to composite structures representing RLV fuel tank walls. The three heat shield materials tested were Alumina-Enhanced Thermal Barrier-12 (AETB-12), Flexible Reusable Surface Insulation (FRSI), and Advanced Flexible Reusable Surface Insulation (AFRSI). Using this test data, predictor equations were developed for the entry hole diameters in the three TPS materials, with correlation coefficients ranging from 0.69 to 0.86. Possible methods are proposed for approximating damage occurring at expected orbital impact velocities higher than tested, with references to other published work.

Robinson, Jennifer H.↗
NASA NTRS2001

Technologies for Icy Bodies Access

Recent events in planetary exploration have profoundly changed the way both space scientists and the public regard the solar system and our place in it. These events include the Galileo data suggesting subsurface oceans in the Jovian system, ever stronger suggestions of near-surface water on Mars, as well as the complex structure observed for the Mars polar caps. And, of course, interest in icy cometary bodies is as old as humankind. Finally, the Mars north polar cap may conceivably cover and protect an ancient ocean floor, an obvious candidate ancient or extant habitat. In short, our interest in searching for life embraced early on the search for liquid water, and that has led us to an additional appreciation for water ice as both a commonplace partner with liquid water and as an issue to be addressed in the exploration of a host of interesting sites. In general, the spectrum of specialized technology for space exploration has not yet been broadened to include the requirements brought about by exploration of icy sites. We argue that technologies for access, operations, and science in icy solar system sites must be examined and their prioritized development initiated in order to successfully plan missions to these compelling sites over the next two decades. Additional information is contained in the original extended abstract.

Carsey, F. D.↗
NASA NTRS2008

Heat Sponge: A Concept for Mass-Efficient Heat Storage

The heat sponge is a device for mass-efficient storage of heat. It was developed to be incorporated in the substructure of a re-entry vehicle to reduce thermal- protection-system requirements. The heat sponge consists of a liquid/vapor mixture contained within a number of miniature pressure vessels that can be embedded within a variety of different types of structures. As temperature is increased, pressure in the miniature pressure vessels also increases so that heat absorbed through vaporization of the liquid is spread over a relatively large temperature range. Using water as a working fluid, the heat-storage capacity of the liquid/vapor mixture is many times higher than that of typical structural materials and is well above that of common phase change materials over a temperature range of 200 F to 700 F. The use of pure ammonia as the working fluid provides a range of application between 432 deg R and 730 deg R, or the use of the more practical water-ammonia solution provides a range of application between 432 deg R and 1160 deg R or in between that of water and pure ammonia. Prototype heat sponges were fabricated and characterized. These heat sponges consisted of 1.0-inch-diameter, hollow, stainless-steel spheres with a wall thickness of 0.020 inches which had varying percentages of their interior volumes filled with water and a water-ammonia solution. An apparatus to measure the heat stored in these prototype heat sponges was designed, fabricated, and verified. The heat-storage capacity calculated from measured temperature histories is compared to numerical predictions.

Splinter, Scott C.↗
NASA NTRS2009

Ballistic Performance of Porous-Ceramic, Thermal-Protection-Systems

Porous-ceramic, thermal protection systems are used heavily in current reentry vehicles like the Space Shuttle and are currently being proposed for the next generation of manned spacecraft, Orion. These materials insulate the structural components of a spacecraft against the intense thermal environments of atmospheric reentry. Furthermore, these materials are also highly exposed to space environmental hazards like meteoroid and orbital debris impacts. This paper discusses recent impact testing up to 9 km/s, and the findings of the influence of material equation-of-state on the simulation of the impact event to characterize the ballistic performance of these materials. These results will be compared with heritage models1 for these materials developed from testing at lower velocities. Assessments of predicted spacecraft risk based upon these tests and simulations will also be discussed.

Christiansen, E. L.↗
NASA NTRS2009

Ballistic Performance of Porous Ceramic Thermal Protection Systems at 9 km/s

Porous-ceramic, thermal-protection-systems are used heavily in current reentry vehicles like the Orbiter, and they are currently being proposed for the next generation of manned spacecraft, Orion. These materials insulate the structural components and sensitive electronic components of a spacecraft against the intense thermal environments of atmospheric reentry. Furthermore, these materials are also highly exposed to space environmental hazards like meteoroid and orbital debris impacts. This paper discusses recent impact testing up to 9 km/s on ceramic tiles similar to those used on the Orbiter. These tiles have a porous-batting of nominally 8 lb/cubic ft alumina-fiber-enhanced-thermal-barrier (AETB8) insulating material coated with a damage-resistant, toughened-unipiece-fibrous-insulation (TUFI) layer.

Miller, Joshua E.↗
NASA NTRS2003

Electrical-Impedance-Based Ice-Thickness Gauges

Langley Research Center has developed electrical-impedance-based ice-thickness gauges and is seeking partners and collaborators to commercialize them. When used as parts of active monitoring and diagnostic systems, these gauges make it possible to begin deicing or to take other protective measures before ice accretes to dangerous levels. These gauges are inexpensive, small, and simple to produce. They can be adapted to use on a variety of stationary and moving structures that are subject to accumulation of ice. Examples of such structures include aircraft, cars, trucks, ships, buildings, towers, power lines (see figure), power-generating equipment, water pipes, freezer compartments, and cooling coils. A gauge of this type includes a temperature sensor and two or more pairs of electrically insulated conductors embedded in a surface on which ice could accumulate. The electrical impedances of the pairs of conductors vary with the thickness of any ice that may be present. Somewhat more specifically, when the pairs of conductors are spaced appropriately, the ratio between their impedances is indicative of the thickness of the ice. Therefore, the gauge includes embedded electronic circuits that measure the electrical impedances, plus circuits that process the combination of temperature and impedance measurements to determine whether ice is present and, if so, how thick it is. Of course, in the processing of the impedance measurements, the temperature measurements help the circuitry to distinguish between liquid water and ice. The basic design of a gauge of this type can be adapted to local conditions. For example, if there is a need to monitor ice over a wide range of thickness, then the gauge can include more than two sets of conductors having various spacings.

Weinstein, Leonard↗
NASA NTRSDate not supplied

Analytical Calculation of the Energy Deposition Spectrum and Average Dose to A Spherical Target at All Impact Parameters

Microdosimetry is used to estimate quality factors for risk assessment in radiation protection and to quantify relative biological effectiveness (RBE) for treatment planning of hadron radiation therapy. Radiation physics has shown that energetic ions deposit energy in a complex manner: the track structure. The Local Effect Model (LEM) is often used as an approximation to describe this complex track structure. We have previously calculated an analytical expression for the dose to a spherical target fully located in the penumbra of an ion track using the LEM. In this work, the calculation has been extended to all impact parameters. Furthermore, using these analytical expressions, it was possible to obtain the theoretical energy deposition spectra to a sphere irradiated uniformly.

Ianik Plante↗
DOE OSTI2025

Dual function of Candida auris mannosyltransferase, MNT5, in biofilm community protection from antifungal therapy and the host

Screen of mutants from a mannosyltransferase family identified the importance of MNT5 for C. auris biofilm drug resistance and neutrophil evasion. Biochemical analysis of the mnt5∆ mutant matrix and cell wall identified alterations in the mannan structures. Resistance and matrix for mnt5∆ were restored with delivery of wild-type matrix via extracellular vesicles. Analysis of the mnt5∆ cell wall revealed a reduction in mannan and compensatory increase in cell surface glucan and chitin, suggesting a role for MNT5 in mannan masking of pathogen-associated molecular patterns.

Candida auris↗
DOE OSTI2026

Influence of cellular redox reactions on the structure and function of light harvesting and photosystems

Photosynthesis enables the conversion of one of the most abundant and free forms of energy, sunlight, into chemical bonds through the utilization of highly tailored protein complexes. These enzymes work in unison to absorb, convert, and transform light into high-energy electrons which are used for various functions important to metabolism and cellular protection. Over the last ∼50 years, photosynthetic organisms, such as cyanobacteria, have been adapted and engineered to produce valuable compounds like hydrogen and ethylene, among others. Often this is performed by removing native and/or adding in exogenous energy utilization pathways so that light energy is re-directed towards the synthesis of desired compounds. However, the interplay between primary light capture, conversion reactions, and the downstream electron utilization sinks is not fully understood. Further complicating these strategies are the plethora of compensatory mechanisms that facilitate steady electron flow and the maintenance of photosynthesis under dynamic conditions. This manifests as structural and functional plasticity of the photosynthetic machinery, often seen in modulations of oligomeric compositions or changes in protein-protein interactions and coupling with redox enzymes. Understanding these mechanisms is crucial to biotechnology applications because re-engineering electron utilization sinks has profoundly different effects on the light capture and conversion reactions of photosynthesis. Optimization requires a molecular-level understanding of the functional interrelationships between electron sinks and photosynthetic components that influence photosynthetic efficiencies to realize potential improvements in product yields. Here, we aim to highlight how perturbation of reductive reactions is revealing the functional plasticity in key components of the photosynthetic energy transduction pathway.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Isolation, Characterization, and Depolymerization of L -Cysteine Substituted Eucalyptus Lignin

Lignin condensation reactions are hard to avoid or control during separation, which is a deterrent to lignin isolation and post-conversation, especially for the full utilization of lignocelluloses. Selective protection of β-aryl ether linkages in the isolation process is crucial to lignin valorization. Herein, a two-step acid/alkali separation method assisted with l-cysteine for eucalyptus lignin separation is developed, and the isolated L -cysteine lignins (LCLs) are comprehensively characterized by 2D NMR, 31 P NMR, thioacidolysis, etc. Compared to the two-step control treatment, a much higher β-O-4 content is preserved without reducing the separation efficiency assisted by L -cysteine, which is also significantly higher than alkali lignin and kraft lignin. The results of hydrogenolysis show that LCLs generate a much higher monomer yield than that of control sample. Structural analysis of LCLs suggests that lignin condensation reaction, to some extent, is suppressed by adding L -cysteine during the two-step acid/alkali separation. Further, mechanistic studies using dimeric model compound reveals that L -cysteine may be the α-carbon protective agent in the two-step separation. The role of L -cysteine in the two-step lignin isolation method provides novel insights to the selective fractionation of lignin from biomass, especially for the full valorization of lignocellulosic biomass.

09 BIOMASS FUELS↗
NASA NTRS2002

NASA Glenn/AADC Collaboration Optimized Erosion Coatings for Inlet Guide Vanes

There is a need for lightweight, durable materials and structures to reduce the weight of propulsion systems. Polymer matrix composites (PMC's) are promising materials for aerospace applications because of their high strength-to-weight ratio relative to metals. Unfortunately, they are limited to applications where they are not exposed to hightemperature oxidizing atmospheres and/or particulates from ingested air. This is because oxidation and erosion occur on the surface, leading to weight loss, nodulation, and/or cracking on the surface, and a consequent decline of mechanical properties over time. Although prior research has shown that oxidation can be slowed when metallic or ceramic coatings are applied onto PMC's, there remains a need for erosion-resistant coatings that protect PMC's from high-velocity particulates in the engine flow path. These erosionresistant coatings could extend the life of polymer composites. Polymer composites are heavily damaged without an erosion-resistant coating because they are not as hard as metallic engine structures. The effectiveness and life of the coatings depends on their inherent properties as well as on the interaction between the coating and the PMC. Since polymers, in general, have high thermal expansion coefficients in comparison to metals and ceramics, failure of the coatings often occurs at this interface. The objective of this research is to develop strategies to improve this interface and tailor overlays for erosion resistance. The bondcoat, which was developed at the NASA Glenn Research Center, is composed of zinc blended with polyimides to improve the compatibility between the PMC and the overlay material. Initial coating trials at AADC produced vanes that had poor bonding between the overlay and bondcoats. Subsequently, Glenn successfully demonstrated that high-quality plasma-sprayed erosion coating systems could be applied to these guide vanes. Inlet guide vanes from AE 3007 engines fiber composites were coated using a coating system composed of a bondcoat and a hard topcoat. Optimization of the plasma spray process has led to plans for future erosion testing in gas turbine engine environments.

Sutter, James K.↗
DOE OSTI2023

Haldane topological spin-1 chains in a planar metal-organic framework

Haldane topological materials contain unique antiferromagnetic chains with symmetry-protected energy gaps. Such materials have potential applications in spintronics and future quantum computers. Haldane topological solids typically consist of spin-1 chains embedded in extended three-dimensional (3D) crystal structures. Here, we demonstrate that [Ni(μ-4,4'-bipyridine)(μ-oxalate)] n (NiBO) instead adopts a two-dimensional (2D) metal-organic framework (MOF) structure of Ni 2+ spin-1 chains weakly linked by 4,4'-bipyridine. NiBO exhibits Haldane topological properties with a gap between the singlet ground state and the triplet excited state. The latter is split by weak axial and rhombic anisotropies. Several experimental probes, including single-crystal X-ray diffraction, variable-temperature powder neutron diffraction (VT-PND), VT inelastic neutron scattering (VT-INS), DC susceptibility and specific heat measurements, high-field electron spin resonance, and unbiased quantum Monte Carlo simulations, provide a detailed, comprehensive characterization of NiBO. Vibrational (also known as phonon) properties of NiBO have been probed by INS and density-functional theory (DFT) calculations, indicating the absence of phonons near magnetic excitations in NiBO, suppressing spin-phonon coupling. The work here demonstrates that NiBO is indeed a rare 2D-MOF Haldane topological material.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Engineering Privacy at the Edge: A Practical Guide to Differential Privacy in System Architectures

The rapid expansion of distributed and edge computing platforms—spanning autonomous vehicles, IoT sensors, and healthcare monitors—has heightened concerns about data privacy. Differential Privacy (DP) offers a rigorous mathematical framework to protect sensitive information while retaining analytical utility. This tutorial introduces the foundations of DP for both numerical and categorical datasets and extends the discussion to correlation-aware techniques tailored for structured and high-dimensional data. Hands-on demonstrations will begin with the PETINA (Privacy prEservaTIoN Algorithms) package for numerical data and continue with MIC-DP (Maximum Information Correlated Differential Privacy) for tabular data. Designed for researchers and practitioners in secure systems, embedded architectures, and AI accelerators, the tutorial emphasizes practical and scalable methods for integrating DP into real-world system designs.

Kotevska, Olivera [ORNL] (ORCID:0000000316772243)↗
DOE OSTI2021

Interactions of Aqueous Surface Treatments with Magnesium Alloy

Magnesium, the lightest structural metal, has recently been identified as an important substrate for weight reduction in automotive, aerospace, personal electronics, and many other industries. Magnesium’s unique chemistry, however, makes it challenging to protect from corrosion and incorporate with other materials. Cleaners are the first step in any pretreatment process, and understanding their role in surface preparation for corrosion prevention is crucial to making magnesium substrate a viable solution for lightweighting. In this work, we explore the relationship between cleaner composition, pH, etch rate, and panel morphology post-cleaning to understand how various cleaners interact with magnesium alloy. Our findings broaden the pool of possible bath chemistries that provide safe and effective surface cleaning of magnesium substrate.

Harris, Rachel↗
DOE OSTI2022

Impulse Noise Sampling at 9965 - Armag

One detonation test was monitored for impulse noise at Thunder Range on November 6, 2020. The TNT equivalency for this shot was 100 lbs. Ground zero for this test was located at an open area of Range 7. The Armag, where MOW were remotely located, was just south of the east end of the TR shock tube The purpose of this sampling event was to characterize the noise attenuation provided by the Armag which will be used as the primary firing location in a future test series. To determine attenuation provided by the Armag, one sound level monitor was placed inside and a second monitor was placed outside the hardened structure at the same distance from ground zero. The Armag was located 1300 feet from ground zero. Essential personnel performing these tests were remotely located inside the Armag and wore hearing protection with a minimum NRR of 23. Members of the Workforce (MOW) who are exposed to noise levels above 140 dBC, regardless of hearing protection worn, are required to be enrolled into the SNL Hearing Conservation Program which includes audiometric testing, online training (HCP100) and wearing hearing protection.

42 ENGINEERING↗
NASA NTRS1990

Information System Life-Cycle And Documentation Standards (SMAP DIDS)

Although not computer program, SMAP DIDS written to provide systematic, NASA-wide structure for documenting information system development projects. Each DID (data item description) outlines document required for top-quality software development. When combined with management, assurance, and life cycle standards, Standards protect all parties who participate in design and operation of new information system.

Source record↗
NASA NTRS1993

Space Shuttle Orbiter thermal protection system design and flight experience

The Space Shuttle Orbiter Thermal Protection System materials, design approaches associated with each material, and the operational performance experienced during fifty-five successful flights are described. The flights to date indicate that the thermal and structural design requirements were met and that the overall performance was outstanding.

Curry, Donald M.↗
NASA NTRS1993

Spacecraft materials: Comparison between flight results obtained on LDEF and MIR

Two flight experiments dedicated to the study of the performance of materials in space have been carried out. Material samples have been exposed passively to low-Earth orbit (LEO) environment, then retrieved for laboratory study. The first experiment was conducted in the framework of the FRECOPA project and was flown on the trailing edge of the Long Duration Exposure Facility (LDEF) (exposure to vacuum and ultraviolet (UV) radiation for 5.5 years). The experiment COMES was installed outside of the MIR space station during an extravehicular activity; it was exposed to vacuum, O-atoms, and UV radiation for 1.1 year; and it was brought back to Earth by cosmonauts. The difference in exposure conditions and the use of transparent filters protecting some samples of COMES enable to differentiate the effects of UV radiation and oxygen atoms. The degradations of several thermal control coatings (paints, metalized polymeric films with and without ITO), structural materials, and optical components have been observed, measured, and compared after these two flight experiments. This paper summarizes various 'lessons learned' that can be used to identify aspects of space aging, to orient future research in this field, and to assist in spacecraft design.

Guillaumon, Jean-Claude↗