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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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1,258 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

Management and Performance of APPLE Battery in High Temperature Environment

India's first experimental communication satellite, APPLE, carried a 12 AH Ni-Cd battery for supplying power during eclipse. Failure to deploy one of the two solar panels resulted in the battery operating in a high temperature environment, around 40 C. This also resulted in the battery being used in diurnal cycles rather than just half yearly eclipse seasons. The management and performance of the battery during its life of two years are described. An attempt to identify the probable degradation mechanisms is also made.

Suresh, M. S.↗
NASA NTRS1987

Advances in nickel hydrogen technology at Yardney Battery Division

The current major activites in nickel hydrogen technology being addressed at Yardney Battery Division are outlined. Five basic topics are covered: an update on life cycle testing of ManTech 50 AH NiH2 cells in the LEO regime; an overview of the Air Force/industry briefing; nickel electrode process upgrading; 4.5 inch cell development; and bipolar NiH2 battery development.

Bentley, J. G.↗
NASA NTRS2019

Evaluation of Various Methods for Determining Bulk Compositions of Chondrules and Other Objects in Petrographic Thin Sections

Studies of many objects in petrographic thin section, such as melt inclusions in igneous rocks, chondrules and Ca-Al rich inclusions in chondritic meteorites, or clasts in lunar and other breccias, require or can benefit from knowledge of their bulk compositions. Given the scarcity of these materials, the reluctance of curators to provide more abundant material, and the extreme difficulty of cleanly separating such objects from their rock matrices, geochemical and cosmochemical studies need the ability to determine their bulk compositions from in situ methods, such as defocused beam analysis, or quantitative chemical mapping by electron beam methods.

Daniel Kent Ross↗
NASA NTRS1984

Ni-cd Battery Life Expectancy in Geosynchronous Orbit

The feasibility of using nickel cadmium batteries as an alternate if flight qualified NiH2 batteries are not available is explored. Battery life expectancy data being a key element of power system design, an attempt is made to review the literature, life test data and in orbit performance data to develop an up to date estimate of life expectancy for NiCd batteries in a geosynchronous orbit.

Broderick, R. J.↗
NASA NTRSDate not supplied

Evaluating Crystallinity in Thermoplastic composites

Polymer matrix composites (PMCs) offer many benefits for the aerospace industry due to their potential for weight reduction when compared to metal or ceramic based materials. Most PMCs currently in flight use thermoset matrices, however, thermoplastic resins are being explored as alternatives due to their ability to be remelted, which is of particular interest due to the potential for in-situ repair and manufacturing required in space. Most thermoplastic resins are semicrystalline polymers. The properties of semicrystalline thermoplastics are largely influenced by their crystallinity, which can vary due to many factors including thermal treatments, environmental conditions, and mechanical deformation. Monitoring the crystallinity of thermoplastic composites is key to ensuring these materials reliably meet the high demands required by space exploration. This talk discusses the use of multiple techniques such as Polarized Light Optical Microscopy and Fourier-Transform Infrared Spectroscopy to characterize the crystallinity in various thermoplastic composites, including carbon fiber reinforced PMCs and novel bio-based Martian and Lunar regolith composites designed for in-situ manufacturing. This work aims to provide the fundamental data necessary to understand the effects of crystallinity on thermoplastic PMCs, which is key to advancing their use in space applications.

Thermoplastics↗
NASA NTRS1965

Solar-Wind Bombardment of a Surface in Space

The solar wind is described and its effects on surfaces are reviewed. Experimental results are given for materials subjected to simulated solar-wind bombardment. Among the effects discussed are sputtering-type erosion, chemical reaction with paint vehicles and reduction of oxide pigments, and production of lunar-surface optical characteristics in a basalt powder.

Solar Wind↗
NASA NTRSDate not supplied

In-Space Laser Forming Simulated Under Thermal Vacuum (TVAC) Conditions

NASA Marshall Space Flight Center is investigating laser forming under thermal vacuum conditions representative of the space environment through a partnership with the DARPA NOM4D program. The thermal gradient mechanism (TGM) is used to bend a metal sheet towards the laser optics. Laser equipment and process parameters are being optimized for thermal vacuum conditions. Such conditions are representative of the extreme cold and hot temperatures and high vacuum that exist on orbit or on the lunar surface. in situ photogrammetry and thermography assess the bend/counterbend and elucidate the TGM in thermal vacuum. Structured light scanning and metallography after bending reveal the macroscopic and microscopic structure after TGM.

thermal vacuum↗
NASA NTRS2026

Hermal Evolution of Volatile-Rich Planetesimals: Implications for Lithological Diversity in Ryugu and CI Chondrites

Ryugu samples and CI chondrites record aqueous alteration processes in primitive, volatile-rich planetesimals and exhibit a wide range of lithologies defined by mineral assemblages and alteration degrees as proposed to be types I–VI in [4]. The similarity in lithological diversity and proportions between Ryugu and CIs suggests that they originated from parent bodies with comparable internal structures and thermal histories. However, the mechanism responsible for generating such lithological diversity within a single parent body remains unclear.

S Yamazaki↗
NASA NTRS2026

Modeling Study of Hatch Spacing’s Effect on Grain Morphology in Repairing Damaged Metal Parts with Welding and Hatch Spacing’s Potential Use in Lunar Exploration

The welding process is a potential way of repairing a damaged metal component, especially cavity damage caused by a harsh environment like the lunar environment, which is characterized by large temperature differences and reduced gravity. The adjustment of welding parameter (e.g., hatch spacing) can improve production efficiency in the repair process. Seen from the microstructural level, hatch spacing sensitivity affects the metallic grain evolution and morphology in the welding process, which can further influence a repaired part’s mechanical properties; however, the study of hatch spacing’s effect on microstructure is challenging. Traditional experimental procedures are costly and time-consuming, and any change in hatch spacing value needs roll-back of experimental procedure. A modeling study can address the above challenges in experimental observation. In this research, a modeling approach based on the Kinetic Monte Carlo (KMC) Potts theory was used to simulate grain evolution and morphology with three hatch spacings. Through quantifying and analyzing the predicted grain morphologies, the effect of hatch spacing on microstructure in a welding-fabricated part was investigated. The predicted grain morphologies were validated with an EBSD image of welding microstructure, which has been published before. The primary grain morphologies were columnar grains with a small amount of fine equiaxed grains formed in the scanning path centerline. When increasing the hatch spacing, the columnar grains become larger and more lengthy, while the effect of hatch spacing on the equiaxed grains is not obvious.

Welding for repairing↗
NASA NTRS1994

Bifurcation of Rotating Liquid Drops: Results From USML-1 Experiments in Space

Experiments on rotational bifurcation of liquid drops, in which the drops were levitated and spun using acoustic fields in a low-gravity environment, were conducted during the first United States Microgravity Laboratory (USML-1) Space Shuttle flight. The experiments have successfully resolved the discrepancies existing between the previous experimental results and the theoretical predictions. In the case of a spherical drop, for which theory exists, the results agree well with the predictions. In the case of flattened drops, the experiments have established a family of curves, with the spherical drop as the limiting case.

T G Wang↗
NASA NTRSDate not supplied

Examination of Regional Trends in Low Level Cloud Properties Found in the Aqua-MODIS Satellite Record

Clouds have a pronounced influence on the Earth?s climate. Relative to cloud free conditions, they cool the planet by increasing the amount of solar radiation reflected back to space and reducing the amount of sunlight reaching the surface, but they warm the planet by decreasing the amount of thermal infrared radiation escaping to space and increasing the amount reaching the surface (a greenhouse effect). The global mean net cloud radiative effect (CRE) is about -20 W/m2, a cooling effect at both the top-ofatmosphere and surface. Given the magnitude of CRE?s, it is expected that changes in cloud properties could be a significant factor in climate change due to anthropogenic forcing?s, yet cloud feedbacks are not well known and remain one of the largest uncertainties in climate prediction. This paper explores relationships between coincident observations of atmospheric aerosols, clouds and radiation derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and from the Clouds and the Earth?s Radiant Energy System (CERES) instruments on the Aqua satellite. We investigate several interesting regional trends that have emerged in the nearly 18-year satellite record that suggest correlation between changes in low-level cloud properties and changes in aerosol optical depth that may be associated with changes in pollution emissions and possibly with other factors. MERRA reanalysis of meteorological conditions and aerosol particulate species are investigated to help better understand the potential mechanisms responsible for the observed cloud property trends. Finally, we analyze a new CERES flux by cloud type dataset in order to try and isolate the associated trends in low-level cloud radiative effects. It is anticipated that this study using long-term observations of clouds, aerosols and radiative fluxes combined with model reanalysis data will contribute to an improved understanding of cloud climate feedbacks.

William L Smith Jr.↗
NASA NTRS1984

Performance of the Lester battery charger in electric vehicles

Tests are performed on an improved battery charger. The primary purpose of the testing is to develop test methodologies for battery charger evaluation. Tests are developed to characterize the charger in terms of its charge algorithm and to assess the effects of battery initial state of charge and temperature on charger and battery efficiency. Tests show this charger to be a considerable improvement in the state of the art for electric vehicle chargers.

Vivian, H. C.↗