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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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1,514 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Life test of NiH2 flight battery

Life cycle tests being run on the 50 A lightweight nickel hydrogen flight battery are discussed and the preliminary results are presented.

Gandel, M. G.↗
NASA NTRS2008

Characterization of a New Phase and Its Effect on the Work Characteristics of a Near-Stoichiometric Ni30Pt20Ti50 High-Temperature Shape Memory Alloy (HTSMA)

A new phase observed in a nominal Ni 30 Pt 20 Ti 50 (at.%) high temperature shape memory alloy has been characterized using transmission electron microscopy and 3-D atom probe tomography. This phase forms homogenously in the B2 austenite matrix by a nucleation and growth mechanism and results in a concomitant increase in the martensitic transformation temperature of the base alloy. Although the structure of this phase typically contains a high density of faults making characterization difficult, it appears to be trigonal (-3m point group) with a o ~1.28 nm and c o ~1.4 nm. Precipitation of this phase increases the microhardness of the alloy substantially over that of the solution treated and quenched single-phase material. The effect of precipitation strengthening on the work characteristics of the alloy has been explored through load-biased strain-temperature testing in the solution-treated condition and after aging at 500 ºC for times ranging from 1 to 256 hours. Work output was found to increase in the aged alloy as a result of an increase in transformation strain, but was not very sensitive to aging time. The amount of permanent deformation that occurred during thermal cycling under load was small but increased with increasing aging time and stress. Nevertheless, the dimensional stability of the alloy at short aging times (1-4 hours) was still very good making it a potentially useful material for high-temperature actuator applications.

A Garg↗
NASA NTRS1991

Resistor Extends Life Of Battery In Clocked CMOS Circuit

Addition of fixed resistor between battery and clocked complementary metal oxide/semiconductor (CMOS) circuit reduces current drawn from battery. Basic idea to minimize current drawn from battery by operating CMOS circuit at lowest possible current consistent with use of simple, fixed off-the-shelf components. Prolongs lives of batteries in such low-power CMOS circuits as watches and calculators.

Wells, George H., Jr.↗
NASA NTRS2026

Assessment of Aircraft Electric Engine Regulatory Special Conditions

This report provides a regulatory gap assessment of the Federal Aviation Administration (FAA) and the European Union Aviation Safety Agency (EASA) Special Conditions (SC) for electric engines. This information is presented to support ongoing international harmonization efforts for electric engine certification, to establish a level of safety consistent across regulatory bodies and equivalent to that of existing combustion engines. HS Advanced Concepts LLC assembled a team of subject-matter experts to develop a comprehensive comparison of the regulatory text of EASA SC E-19 and the FAA special conditions for the certification of electric engines. The team included Mr. Chris Baczynski of BAC Aerospace Inc. and Mr. Zach Kaufman, formerly with magniX.

aircraft certification↗
NASA NTRSDate not supplied

Seeking & Evaluating Applications of SAWs (SEASAWs)

Surface Acoustic Wave sensors (SAWs) offer a battery less, wireless, passive, noninvasive, durable means of sensing which might be appealing to many fields in space technology. Developments in many aspects of SAWs including the miniaturization of associated hardware, improvements in interrogation and device fabrication / characterization allow for the use of SAWs in many aerospace settings where traditional sensors may have sufficed but SAWs might enhance. In order to place this technology in relevant environments, an inherent understanding of operation and capabilities must be understood. With the many possibilities of SAWs in their implementation, breaking down their tradeoffs and primary systems allows for their application.

Michael Szostak↗
NASA NTRS1985

Nondestructive Evaluation of Composites By Optical Time Domain Reflectometry

Results in the measurement of slowly varying mechanical loading functions on composites using optical time domain reflectometry (OTDR) in imbedded optical fiber during both simulated manufacture and use are reviewed. First, the basic theoretical and experimental principles of the OTDR system are described. Next, the mechanical system of the composite and the imbedded fiber is analyzed. Results of measurement obtained for various loading functions applied to material specimens are then described and system limitations on spatial resolution, strain amplitude sensitivity, and frequency response are explained in terms of the range and resolution limits of the OTDR system.

R O Claus↗
NASA NTRS2004

Thermal Imaging of Aerospace Battery Cells

The objective of the research covered by this viewgraph presentation is to understand the thermal characteristics of a cylindrical aerospace battery cell by studying the surface thermal properties. The batteries tested include a nickel hydrogen cell (NiH2), and a lithium-ion cell (Li-ion).

Shue, Jack↗
NASA NTRSDate not supplied

Demonstrations: A Path to the Future of Aviation

These slides were given as part of Panel 7: “Electric Flight Demonstrations: Test Results, Upcoming Tests, and Certification” a part of iTEC+EATS 2026 held in Novi MI. The presentation represents NASA’s recent and current investments in demonstrating megawatt and multi-megawatt electrified aircraft propulsion

demonstrator↗
NASA NTRS1970

Prevention of Coupled Structure-Propulsion Instability (POGO) On The Space Shuttle

Many liquid-propellant rocket vehicles have experienced longitudinal vibration, nicknamed pogo after the jumping stick, due to an instability arising from interaction of the vehicle structure with the propulsion system. These vibrations can produce an intolerable environment for astronauts and equipment, can overload vehicle structure, and can lead to loss of propulsion performance. A NASA monograph concerned with the prevention of pogo is well on its way toward publication and should serve as a useful guide to design for the Space Shuttle. The paper will briefly describe the nature of the pogo phenomenon, present a summary of past instabilities, relate the possible deleterious effects of pogo, and discuss the contents of the design criteria monograph. Finally, research tasks are recommended for support of pogo development activities on the Space Shuttle.

S. Rubin↗
NASA NTRS1968

Processing and Manufacture of Composite Propellants

This paper is a chemical engineering unit processing treatment of the steps involved in the manufacture of solid propellant motors. The author treats the major processes of raw material preparation, mixing, casting and curing by describing equipment, the processing, steps and some engineering considerations associated therewith. The three simultaneous processes occurring within the solid propellant nixing, namely, homogenization, wetting and curing, are discussed in more detail, briefly touching on control of these reactions and the engineering trade-offs among them.

J F Tormey↗