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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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NASA NTRS1997

Performance Comparison Between NiH2 Dry Sinter and Slurry Electrode Cells

The electrical and thermal performance of dry sinter and slurry process electrode cells manufactured for the Hubble Space Telescope (HST) batteries have been characterized for a matrix of operating conditions over the temperature range from 14 to 86 F at various charge control levels. The dry sinter process electrode cells tested are similar to the onboard HST NiH2 cells. The slurry process electrode cells were developed to be less susceptible to electrode expansion and impedance changes with life. Both cell types were impregnated by the aqueous electrochemical process. Test conditions included standard capacity tests and electrical cycling using 96-minute cycling regimens incorporating gr depth-of-discharge (DOD) cycles. The dry sinter process electrodes have higher operating capacities to 1.20V/cell, but both electrode types have similar heat dissipation for the conditions tested. The results of the testing included cyclic heat generation during a typical 96-minute cycle, operating capacity data vs. cutoff voltage to generate a temperature-compensated voltage curve, and voltage characteristics suitable to develop a voltage prediction model. Analysis of data shows differences in the discharge voltage plateaus operating conditions evaluated. This is the basis for recommended changes in the battery charge control.

Armantrout, J. D.↗

NASA NTRS1998

Evaluation of 20 Ah Li Ion Cells

Lithium ion cells of 20 Ah capacity were fabricated by Bluestar Advanced Technology Corporation, Canada under a developmental contract from US Air Force. In this paper, we report our studies on the evaluation of these cells under various test conditions. These include generic test conditions such as discharges and charges at different temperatures to understand the rate-limiting processes in the discharge/charge processes as a function of temperature, and cycle life under standard cycling conditions (100% DOD) at ambient temperature. In addition, tests are being done to ascertain the performance of the cells in the Mars 2001 Lander application, which includes pulse testing of the cells at 60 A and 40 A loads for 100 mS and 1 min., respectively at different states of charge and temperatures, and cycling at low temperature at partial depths of discharge.

Smart, Marshall↗

NASA NTRS1999

Technology Projections for Solar Dynamic Power

Solar Dynamic power systems can offer many potential benefits to Earth orbiting satellites including high solar-to-electric efficiency, long life without performance degradation, and high power capability. A recent integrated system test of a 2 kilowatt SD power system in a simulated space environment has successfully demonstrated technology readiness for space flight. Conceptual design studies of SD power systems have addressed several potential mission applications: a 10 kilowatt LEO satellite, a low power Space Based Radar, and a 30 kilowatt GEO communications satellite. The studies show that with moderate component development, SD systems can exhibit excellent mass and deployed area characteristics. Using the conceptual design studies as a basis, a SD technology roadmap was generated which identifies the component advances necessary to assure SD systems a competitive advantage for future NASA, DOD, and commercial missions.

Mason, Lee S.↗

NASA NTRS1997

Future Spacelift Requirements Study

This study addresses future space applications and the derived requirements these potential applications will have on future spacelift systems. This NASA sponsored activity is a comprehensive study of potential missions including those of the military, civil, and commercial users. The study objectively evaluated the key architectural requirements for future launch systems. The results of this study are technical, economic, and policy analyses of future spacelift systems. It is intended to assist NASA and DOD decision-makers in planning technical investments and establishing policy for future U.S. spacelift systems.

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NASA NTRS1999

NASGRO 3.0: A Software for Analyzing Aging Aircraft

Structural integrity analysis of aging aircraft is a critical necessity in view of the increasing numbers of such aircraft in general aviation, the airlines and the military. Efforts are in progress by NASA, the FAA and the DoD to focus attention on aging aircraft safety. The present paper describes the NASGRO software which is well-suited for effectively analyzing the behavior of defects that may be found in aging aircraft. The newly revised Version 3.0 has many features specifically implemented to suit the needs of the aircraft community. The fatigue crack growth computer program NASA/FLAGRO 2.0 was originally developed to analyze space hardware such as the Space Shuttle, the International Space Station and the associated payloads. Due to popular demand, the software was enhanced to suit the needs of the aircraft industry. Major improvements in Version 3.0 are the incorporation of the ability to read aircraft spectra of unlimited size, generation of common aircraft fatigue load blocks, and the incorporation of crack-growth models which include load-interaction effects such as retardation due to overloads and acceleration due to underloads. Five new crack-growth models, viz., generalized Willenborg, modified generalized Willenborg, constant closure model, Walker-Chang model and the deKoning-Newman strip-yield model, have been implemented. To facilitate easier input of geometry, material properties and load spectra, a Windows-style graphical user interface has been developed. Features to quickly change the input and rerun the problem as well as examine the output are incorporated. NASGRO has been organized into three modules, the crack-growth module being the primary one. The other two modules are the boundary element module and the material properties module. The boundary-element module provides the ability to model and analyze complex two-dimensional problems to obtain stresses and stress-intensity factors. The material properties module allows users to store and curve-fit fatigue-crack growth data. On-line help and documentation are provided for each of the modules. In addition to the popular PC windows version, a unix-based X-windows version of NASGRO is also available. A portable C++ class library called WxWindows was used to facilitate cross-platform availability of the software.

Mettu, S. R.↗

NASA NTRS1999

IEEE 1393 Spaceborne Fiber Optic Data Bus: A Standard Approach to On-Board Payload Data Handling Networks for the AIAA Space Technology Conference and Exposition "Partnering in the 21th Century"

The Spaceborne Fiber Optic Data Bus (SFODB) is the next generation in on-board data handling networks. It will do for high speed payloads what SAE 1773 has done for on-board command and telemetry systems. That is, it will significantly reduce the cost of payload development, integration and test through interface standardization. As defined in IEEE 1393, SFODB is a 1 Gb/s, fiber optic network specifically designed to support the real-time, on-board data handling requirements of remote sensing spacecraft. The network is highly reliable, fault tolerant, and capable of withstanding the rigors of launch and the harsh space environment. SFODB achieves this operational and environmental performance while maintaining the small size, light weight, and low power necessary for spaceborne applications. SFODB was developed jointly by DoD and NASA GSFC to meet the on-board data handling needs of Remote Sensing satellites. This jointly funded project produced a complete set of flight transmitters, receivers and protocol ASICS; a complete Development & Evaluation System; and, the IEEE 1393 standard.

Andrucyk, Dennis J.↗

NASA NTRS1999

1999 Guidance, Navigation, and Control Highlights

This article summarizes the highlights of recent events and developments in guidance, navigation, and control in space, aircraft, and weapons. This article is about 1,200 words long. Information for the article was collected from other NASA Centers, DoD, and industry. All information was previously cleared by the originating organizations. Information for the article was also gathered from Aviation Week and Space Technology, Space News, and similar sources.

Polites, Michael E.↗

NASA NTRS1998

Technology Development Benefits and the Economics Breakdown Structure

This paper describes the construction and application of the EBS (Economics Breakdown Structure) in evaluating technology investments across multiple systems and organizations, illustrated with examples in space transportation technology. The United States Government (USG) has a long history of investing in technology to enable its missions. Agencies such as the National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD) have evaluated their technology development programs primarily on their effects on mission performance and cost. More and more, though, USG agencies are being evaluated on their technology transfer to the commercial sector. In addition, an increasing number of USG missions are being accomplished by industry-led or joint efforts, where the USG provides technology and funding but tasks industry with development and operation of the mission systems.

Shaw, Eric J.↗

NASA NTRS1999

Progress in the Development of Lightweight Nickel Electrode for Nickel-Hydrogen Cell

Development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (Ni-H2) program at the NASA Glenn Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a lighter weight electrode for the nickel-hydrogen cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active material. Initial tests include activation and capacity measurements at five different discharge levels, C/2, 1.0 C, 1.37 C, 2.0 C, and 2.74 C. The electrodes are life cycle tested using a half-cell configuration at 40 and 80% depths-of-discharge (DOD) in a low-Earth-orbit regime. The electrodes that pass the initial tests are life cycle-tested in a boiler plate nickel-hydrogen cell before flight weight design are built and tested.

Britton, Doris L.↗

NASA NTRS1998

1998 Guidance, Navigation, and Control Highlights

This article summarizes the highlights of recent events and developments in guidance, navigation, and control in space, aircraft, and weapons. The article is about 1,200 words long. Information for the article was collected from other NASA Centers, DoD, and industry. All information collected was previously cleared by the originating organizations. Information for the article was also gathered from Aviation Week and Space Technolo2y, Space News, and similar sources.

Polites, Michael E.↗

NASA NTRS1999

Recent Events in Guidance, Navigation, and Control Highlights

This article summarizes the highlights of recent events and developments in guidance, navigation, and control in space, aircraft, and weapons. This article is about 3,600 words long. Information for the article was collected from other NASA Centers, DoD, and industry. All information was previously cleared by the originating organizations. Information for the article was also gathered from Aviation Week and Space Technology, Space News, and similar sources.

Polites, Michael E.↗

NASA NTRS1998

Recent Events in Guidance, Navigation, and Control

This article summarizes the highlights of recent events and developments in guidance, navigation, and control in space, aircraft, and weapons. Information for the article was collected from other NASA Centers, DoD, and industry. All information collected was previously cleared by the originating organizations. Information for the article was also gathered from Aviation Week and Space Technology, Space News, and similar sources.

Polites, Michael E.↗

NASA NTRS1999

1999 Digital Avionics Highlights

Polites, Michael E.↗

NASA NTRS1985

[STS-51C Launch and Landing]

This NASA KSC video release is comprised of live shots covering the day launch and landing of STS-51C/Discovery. The flight crew members were: Thomas K. Mattingly II, Commander; Loren J. Shriver, Pilot; Ellison S. Onizuka, Mission Specialist; James F. Buchli, Mission Specialist; and Gary E. Payton, Payload Specialist. The launch video is presented from several different vantage points and covers the countdown from the launch pad, main engine ignition, liftoff, and solid rocket booster separation. The landing footage contains final descent and approach, landing gear deployment, and touchdown, which was also captured from different locations including a helicopter. STS-51C carried the DoD 85-1 payload and was the first mission dedicated to the Department of Defense.

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NASA NTRS1999

Space Mechanisms Technology Workshop Proceedings

Over the years, NASA has experienced a number of troublesome mechanism anomalies. Because of this, the NASA Office of Safety and Mission Assurance initiated a workshop to evaluate the current space mechanism state-of-the-art and to determine the obstacles that will have to be met in order to achieve NASA's future missions goals. Seventy experts in the field attended the workshop. The experts identified current and perceived future space mechanisms obstacles. For each obstacle, the participants identified technology deficiencies, the current state-of-the-art, and applicable NASA, DOD, and industry missions. In addition, the participants at the workshop looked at technology needs for current missions, technology needs for future missions, what new technology is needed to improve the reliability of mechanisms, what can be done to improve technology development and the dissemination of information, and what do we do next.

Fusaro, Robert L.↗

NASA NTRS1999

Vehicle/Atmosphere Interaction Glows: Far Ultraviolet, Visible, and Infrared

Spacecraft glow information has been gathered from a number of spacecraft including Atmospheric and Dynamic satellites, and Space Shuttles (numerous flights) with dedicated pallet flow observations on STS-39 (DOD) and STS-62 (NASA). In addition, a larger number of laboratory experiments with low energy oxygen beam studies have made important contributions to glow understanding. The following report provides information on three engineering models developed for spacecraft glow including the far ultraviolet to ultraviolet (1400-4000 A), and infrared (0.9-40 microns) spectral regions. The models include effects resulting from atmospheric density/altitude, spacecraft temperature, spacecraft material, and ram angle. Glow brightness would be predicted as a function of distance from surfaces for all wavelengths.

Swenson, G.↗

NASA NTRS1973

Phase 111A Crew Interface Specifications Development for Inflight Maintenance and Stowage Functions

This report presents the findings and data products developed during the Phase IIIA Crew Interface Specification Study for Inflight Maintenance and Stowage Functions, performed by General Electric for the NASA, Johnson Space Center with a set of documentation that can be used as definitive guidelines to improve the present process of defining, controlling and managing flight crew interface requirements that are related to inflight maintenance (including assembly and servicing) and stowage functions. During the Phase IIIA contract period, the following data products were developed: 1) Projected NASA Crew Procedures/Flight Data File Development Process. 2) Inflight Maintenance Management Process Description. 3) Preliminary Draft, General Specification, Inflight Maintenance Management Requirements. 4) Inflight Maintenance Operational Process Description. 5) Preliminary Draft, General Specification, Inflight Maintenance Task and Support Requirements Analysis. 6) Suggested IFM Data Processing Reports for Logistics Management The above Inflight Maintenance data products have been developed during the Phase IIIA study after review of Space Shuttle Program Documentation, including the Level II Integrated Logistics Requirements and other DOD and NASA data relative to Payloads Accommodations and Satellite On-Orbit Servicing. These Inflight Maintenance data products were developed to be in consonance with Space Shuttle Program technical and management requirements.

Carl, John G.↗

NASA NTRS2000

]Space Shuttle Independent Assessment Team

The Shuttle program is one of the most complex engineering activities undertaken anywhere in the world at the present time. The Space Shuttle Independent Assessment Team (SIAT) was chartered in September 1999 by NASA to provide an independent review of the Space Shuttle sub-systems and maintenance practices. During the period from October through December 1999, the team led by Dr. McDonald and comprised of NASA, contractor, and DOD experts reviewed NASA practices, Space Shuffle anomalies, as well as civilian and military aerospace experience. In performing the review, much of a very positive nature was observed by the SIAT, not the least of which was the skill and dedication of the workforce. It is in the unfortunate nature of this type of review that the very positive elements are either not mentioned or dwelt upon. This very complex program has undergone a massive change in structure in the last few years with the transition to a slimmed down, contractor-run operation, the Shuttle Flight Operations Contract (SFOC). This has been accomplished with significant cost savings and without a major incident. This report has identified significant problems that must be addressed to maintain an effective program. These problems are described in each of the Issues, Findings or Observations summarized, and unless noted, appear to be systemic in nature and not confined to any one Shuttle sub-system or element. Specifics are given in the body of the report, along with recommendations to improve the present systems.

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