Search NASA⌕ Search

SEARCH · Search NASA

Results for “reactors/theory of, general introduction to”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

1,557 records · Page 64
All sourcesNASA NTRSDOE OSTI
NASA NTRS2026

Manufacturing and Scale-Up of Natural Fiber Composite eVTOL Propeller Skin and C-Channel

This report presents the manufacturing and scale-up of natural fiber composites for aerospace applications, conducted within NASA’s Convergent Aeronautics Solutions portfolio to advance aircraft capabilities and efficiency. The effort focused on the development and demonstration of two proof-of-concept articles, an Electric Vertical Take-off and Landing (eVTOL) propeller skin and a C-channel, produced through an iterative design and process optimization approach. Best practices and guidance on addressing key challenges with bio-based composite materials and manufacturing is provided. Ideally suited for non-load-bearing structural components, these emerging materials offer potential for weight reduction, vibration damping, noise mitigation, interference-free communication, and cost savings, without compromising the performance of safety-critical primary structures.

Natural fibers↗
NASA NTRSDate not supplied

Under Pressure: The Artemis I Heatshield Char Loss Investigation and Artemis II’s Successful Entry

Following the successful Artemis I skip reentry on December 11, 2022, unexpected char liberation from the Orion heat- shield prompted formation of an Anomaly Response Team to determine root cause and establish flight rationale and corrective actions for subsequent missions. Through a comprehensive investigation including detailed hardware analysis, modeling & simulation, and ground testing, the team determined that the low permeability Avcoat experienced extreme internal gas pressure buildup during the skip entry that could not adequately outgas, leading to crack formation and char liberation. Key discoveries included significant performance differences between permeable and impermeable heatshield regions and successful replication of the anomaly through ground testing. Based on extensive ground testing and analysis, Artemis II flew a modified trajectory without the skip entry to minimize crack-inducing conditions, and successfully splashed down on April 10, 2026 with significantly reduced char loss. For Artemis III and beyond, a corrective action was implemented to produce a more permeable version of Avcoat that will substantially reduce internal pressure accumulation during entry.

Artemis II↗
NASA NTRS2003

Analysis of Surface and Bulk Behavior in Ni-Pd Alloys

The most salient features of the surface structure and bulk behavior of Ni-Pd alloys have been studied using the BFS method for alloys. Large-scale atomistic simulations were performed to investigate surface segregation profiles as a function of temperature, crystal face, and composition. Pd enrichment of the first layer was observed in (111) and (100) surfaces, and enrichment of the top two layers occurred for (110) surfaces. In all cases, the segregation profile shows alternate planes enriched and depleted in Pd. In addition, the phase structure of bulk Ni-Pd alloys as a function of temperature and composition was studied. A weak ordering tendency was observed at low temperatures, which helps explain the compositional oscillations in the segregation profiles. Finally, based on atom-by-atom static energy calculations, a comprehensive explanation for the observed surface and bulk features will be presented in terms of competing chemical and strain energy effects.

Ordering↗
NASA NTRS1967

Battery charge regulator is coulometer controlled

Coulometer controlled battery charge regulator controls nickel/cadmium type primary cells used in space applications. The use of the coulometer as an ampere hour measuring device permits all available current to go to the battery until full charge state is reached, at which time the charge rate is automatically reduced.

Paulkovich, J.↗
NASA NTRS1993

Center for Space Transportation and Applied Research Fifth Annual Technical Symposium Proceedings

This Fifth Annual Technical Symposium, sponsored by the UT-Calspan Center for Space Transportation and Applied Research (CSTAR), is organized to provide an overview of the technical accomplishments of the Center's five Research and Technology focus areas during the past year. These areas include chemical propulsion, electric propulsion, commerical space transportation, computational methods, and laser materials processing. Papers in the area of artificial intelligence/expert systems are also presented.

Source record↗
NASA NTRS1984

Chemically rechargeable battery

Batteries (50) containing oxidized, discharged metal electrodes such as an iron-air battery are charged by removing and storing electrolyte in a reservoir (98), pumping fluid reductant such as formalin (aqueous formaldehyde) from a storage tank (106) into the battery in contact with the surfaces of the electrodes. After sufficient iron hydroxide has been reduced to iron, the spent reductant is drained, the electrodes rinsed with water from rinse tank (102) and then the electrolyte in the reservoir (106) is returned to the battery. The battery can be slowly electrically charged when in overnight storage but can be quickly charged in about 10 minutes by the chemical procedure of the invention.

Graf, James E.↗
NASA NTRS2018

Initial Jitter Analysis of Lynx, a Proposed Future Large Astrophysics Facility

Lynx is an X-Ray telescope large-mission concept for consideration in NASA's 2020 Astrophysics Decadal Survey. A conceptual structural design is evolving that leverages the success and lessons learned from Chandra and that takes into account unique needs of Lynx. Space optics systems require extreme stability. Any motion in-service (thermal effects, structural dynamics, etc.) impacts performance. An initial analysis was performed to predict the first-cut dynamic responses, jitter, at two selected points on the Lynx observatory. One point is on the Lynx X-ray Mirror Assembly (LMA) and the other, on the focal plane Integrated Science Instrument Module (ISIM). Relative motion between these two points was predicted along with vibration spectra. This information will be used in upcoming analyses of the LMA and the ISIM.

J Brent Knight↗
NASA NTRS2002

Evaluation of Cycle Life and Characterization of YTP 45 Ah Li-Ion Battery for EMU

Li-ion batteries, with longer cycle life and higher energy density features, are now more and more attractive and applied in multiple fields. The YTP 45 Ah Li-ion battery has been evaluated here and may be employed in EMU in the future. Evaluations were on: (1) Cycle life tests - 500 cycles total (completed 40 cycles in simulated shuttle use mode and 460 cycles in an accelerated use mode, and recorded differential voltage of individual cell in battery); (2) Characterization test - discharge capacity measurement in environment temperature of -10, 25, 50 C before and after 500 cycles; and (3) Thermal testing - charge and discharge at 50 C and -10 C before and after 500 cycles. The battery showed less than a 9% drop of initial discharge capacity and energy within 500 cycles with 475 cycles 59% DOD plus 25 cycles 100% DOD. The EOD voltage ranged from 16.0 to 18.0 V, which fits the requirement for operating the EMU.

Deng, Yi↗
NASA NTRS1999

International Ultraviolet Explorer (IUE) Battery History and Performance

The "International Ultraviolet Explorer (IUE) Battery History and Performance" report provides the information on the cell/battery design, battery performance during the thirty eight (38) solar eclipse seasons and the end-of-life test data. It is noteworthy that IUE spacecraft was an in-house project and that the batteries were designed, fabricated and tested (Qualification and Acceptance) at the Goddard Space Flight Center. A detailed information is given on the cell and battery design criteria and the designs, on the Qualification and the Acceptance tests, and on the cell life cycling tests. The environmental, thermal, and vibration tests were performed on the batteries at the battery level as well as with the interface on the spacecraft. The telemetry data were acquired, analyzed, and trended for various parameters over the mission life. Rigorous and diligent battery management programs were developed and implemented from time to time to extend the mission life over eighteen plus years. Prior to the termination of spacecraft operation, special tests were conducted to check the battery switching operation, battery residual capacity, third electrode performance and battery impedance.

Rao, Gopalskrishna M.↗
NASA NTRS1985

Mathematical Storage-Battery Models

Empirical formula represents performance of electrical storage batteries. Formula covers many battery types and includes numerous coefficients adjusted to fit peculiarities of each type. Battery and load parameters taken into account include power density in battery, discharge time, and electrolyte temperature. Applications include electric-vehicle "fuel" gages and powerline load leveling.

Chapman, C. P.↗
NASA NTRS1982

Improved multilayer insulation applications

Multilayer insulation blankets used for the attenuation of radiant heat transfer in spacecraft are addressed. Typically, blanket effectiveness is degraded by heat leaks in the joints between adjacent blankets and by heat leaks caused by the blanket fastener system. An approach to blanket design based upon modular sub-blankets with distributed seams and upon an associated fastener system that practically eliminates the through-the-blanket conductive path is described. Test results are discussed providing confirmation of the approach. The specific case of the thermal control system for the optical assembly of the Space Telescope is examined.

George Mikk↗
NASA NTRS2026

Computational Materials for Qualification and Certification (CM4QC) Strategy Document: Maturation of Computational Materials Methods for Aviation-Focused Qualification and Certification of Metal Additive Manufacturing (as an Example of Process-Intensive Materials)

Although considerable scientific and technological advances have been made in recent years in additive manufacturing (AM) processes, these advances have not translated into significant market penetration of AM parts within the aviation industry. It is broadly acknowledged that using traditional qualification and certification (Q&C) approaches for AM components is one of the most significant barriers to broader adoption of AM, resulting in high costs, long product development and certification timelines, and complex design iterations during the product development cycle. A new approach is urgently needed. This document lays out a vision for a new Q&C paradigm with increased use of computational materials (CM) methods aimed at decreasing the time and cost of Q&C of process-intensive material (PIM) approaches in the aviation industry, with AM as the immediate use case. This vision was developed with substantial input from industry, regulatory agencies, government research organizations, and academia.

Edward H Glaessgen↗
NASA NTRS2001

Lithium Ion Battery Design and Safety

This viewgraph presentation makes several recommendations to ensure the safe and effective design of Lithium ion cell batteries. Large lithium ion cells require pressure switches and small cells require pressure disconnects and other safety devices with the ability to instantly interrupt flow. Other suggestions include specifications for batteries and battery chargers.

Au, George↗
NASA NTRS2010

The Extravehicular Maneuvering Unit's New Long Life Battery and Lithium Ion Battery Charger

The Long Life (Lithium Ion) Battery is designed to replace the current Extravehicular Mobility Unit Silver/Zinc Increased Capacity Battery, which is used to provide power to the Primary Life Support Subsystem during Extravehicular Activities. The Charger is designed to charge, discharge, and condition the battery either in a charger-strapped configuration or in a suit-mounted configuration. This paper will provide an overview of the capabilities and systems engineering development approach for both the battery and the charger

Russell, Samuel P.↗
NASA NTRS2009

Data Base and Guidelines Document Developed for Lithium-Ion Battery

Lithium-Ion (Li-Ion) batteries are fast becoming the battery chemistry of choice for aerospace applications requiring (rechargeable) power supplies. These batteries offer high-energy density and high-specific energy combined with excellent rate capability and cycle potential. The increased energy content and operational characteristics of this system require defined safety and handling procedures to ensure the safe implementation. Standardized approaches to defining, determining, and addressing safety, handling, and qualification for Li-Ion batteries have been developed and published as an NESC-sponsored Li-Ion Battery Guidelines Document. A data base was established cataloging cells and batteries that have been considered for aerospace applications.

Data Base and Guidelines↗
NASA NTRS2002

The Design and Use of Calorimeters For Characterization of High-Enthalpy Flows in Arc-Heated Test Facilities

High-enthalpy, arc-heated flows used for aerothermal testing present a challenging environment for flow characterization. This paper describes the design and use of cooled dwell probes used for heat-transfer and pressure characterization of the NASA and United States Department of Defense (DoD) arc facilities located at Moffett Field, CA, and Arnold Air Force Base, TN. Dwell calorimeters designed, fabricated, and tested by Thermal Technologies, Inc. (TTI) in the NASA IHF and the USAF H1 and H2 arc test facilities provide heat flux and pressure data with excellent repeatability. These calorimeters use standard Gardon calorimeter gages and pressure ports with unique cooling systems enabling them to withstand the severe arc-heated environments for durations sufficient for acquisition of steady-state data. The TTI probes have proven very robust in the extreme aerothermal environments of these facilities. This paper provides an overview of calorimeter instruments typically used in arc facilities, discusses design features of the TTI dwell probes, presents selected data acquired by the TTI calorimeters, and provides comparisons with data acquired from using measurement techniques.

D Mark Smith↗
NASA NTRS1986

Satellite battery testing status

Because of the large numbers of satellite cells currently being tested and anticipated at the Naval Weapons Support Center (NAVWPNSUPPCEN) Crane, Indiana, satellite cell testing is being integrated into the Battery Test Automation Project (BTAP). The BTAP, designed to meet the growing needs for battery testing at the NAVWPNSUPPCEN Crane, will consist of several Automated Test Stations (ATSs) which monitor batteries under test. Each ATS will interface with an Automation Network Controller (ANC) which will collect test data for reduction.

Haag, R.↗
NASA NTRS1992

Nickel-hydrogen battery design for the Transporter Energy Storage Subsystem (TESS)

Information is given in viewgraph form on nickel hydrogen battery design for the transporter energy storage subsystem (TESS). Information is given on use in the Space Station Freedom, the launch configuration, use in the Mobile Servicing Center, battery design requirements, TESS subassembley design, proof of principle testing of a 6-cell battery, possible downsizing of TESS to support the Mobile Rocket Servicer Base System (MBS) redesign, TESS output capacity, and cell testing.

Lapinski, John R.↗