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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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Maintaining technical excellence requires a national plan

To meet the challenge of technical excellence, AIA established a rocket propulsion committee to develop the National Rocket Propulsion Strategic Plan. Developing such a plan required a broad spectrum of experience and disciplines. The Strategic Plan team needed the participation of industry, government, and academia. The plan provides, if followed, a means for the U.S. to maintain technical excellence and world leadership in rocket propulsion. To implement the National Rocket Propulsion Strategic Plan is to invest in the social, economic, and technological futures of America. The plan lays the basis for upgrading existing propulsion systems and a firm base for future full scale development, production, and operation of rocket propulsion systems for space, defense, and commercial applications.

Davidson, T. F.↗
NASA NTRS1991

Maintaining consistency in distributed systems

In systems designed as assemblies of independently developed components, concurrent access to data or data structures normally arises within individual programs, and is controlled using mutual exclusion constructs, such as semaphores and monitors. Where data is persistent and/or sets of operation are related to one another, transactions or linearizability may be more appropriate. Systems that incorporate cooperative styles of distributed execution often replicate or distribute data within groups of components. In these cases, group oriented consistency properties must be maintained, and tools based on the virtual synchrony execution model greatly simplify the task confronting an application developer. All three styles of distributed computing are likely to be seen in future systems - often, within the same application. This leads us to propose an integrated approach that permits applications that use virtual synchrony with concurrent objects that respect a linearizability constraint, and vice versa. Transactional subsystems are treated as a special case of linearizability.

Birman, Kenneth P.↗
NASA NTRS1992

Support activities to maintain SUMS flight readiness

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation began about one hour prior to shuttle de-orbit entry maneuver and continued until reaching 1.6 torr (about 86 km altitude). The SUMS mass spectrometer consists of the spare unit from the Viking mission to Mars. Bendix Aerospace under contract to NASA LaRC incorporated the Viking mass spectrometer, a microprocessor based logic card, a pressurized instrument case, and the University of Texas at Dallas provided a gas inlet system into a configuration suited to interface with the shuttle Columbia. The SUMS experiment underwent static and dynamic calibration as well as vacuum maintenance before and after STS 40 shuttle flight. The SUMS flew a total of 3 times on the space shuttle Columbia. Between flights the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399.

Wright, Willie↗
NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 2. Attachment A: Flight 61-C report

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation system (STS). The experiment mission operation begins about 1 hour to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, and STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume is the flight data report for flight 61-C.

Wright, Willie↗
NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 3. Attachment B: Flight STS-35 report, section A

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, and STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents flight data for flight STS-35 in graphical format.

Wright, Willie↗
NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 4. Attachment B: Flight STS-35 report, section B

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume present spectra graphs of the reentry of flight STS-35.

Wright, Willie↗
NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 5. Attachment B: Flight STS-35 report, section C

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, and STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents spectral graphs of the reentry of flight STS-35.

Wright, Willie↗
NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 6. Attachment B: Flight STS-35 report, section D

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents spectral graphs of the reentry of flight STS-35.

Wright, Willie↗
NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 7. Attachment B: Flight STS-35 report, section E

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents data from the reentry of flight STS-35 in tabular and graphical format.

Wright, Willie↗
NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 8. Attachment B: Flight STS-35 report, section F

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents tabular and graphical spectral data of the reentry of flight STS-35.

Wright, Willie↗
NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 9. Attachment C: Flight STS-40 report. Attachment D: SUMS software listing

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume provides a software listing and graphical data gathered from flight STS-40.

Wright, Willie↗
NASA NTRS1994

Endangered and potentially endangered wildlife on John F. Kennedy Space Center and faunal integrity as a goal for maintaining biological diversity

Buffer zones for space operations provide for a wildlife diversity unsurpassed among most federal facilities in the continental U.S. demonstrating the coexistence possible with one of man's greatest technological achievements. This document ranks 119 resident or migratory wildlife species that are endangered or declining. The ranking system herein was based on species' vulnerability to extinction and the relevance of Kennedy Space Center (KSC) for maintaining populations in the U.S. and Florida. One amphibian, 19 reptiles, 80 birds, and 19 mammals were considered endangered or declining. KSC is an integral area for regional species diversity being the focus of the Merritt Island/Cape Canaveral/Turnbull Ecosystem which is part of the Indian River Lagoon watershed, an estuary of national significance. Many species that use this system also use the nearby St. Johns River Basin ecosystem. These two ecosystems are biological corridors between temperate Carolinian and tropical/subtropical Caribbean biotic provinces. Threats to biological diversity on KSC were also reviewed. Traditional environmental assessments, resulting from environmental regulation guidelines, focus on environmental contaminants and habitat lost due to construction. However, this review suggested that small population sizes, isolation of populations, ecosystem and habitat fragmentation, road mortality, and other edge effects may represent more critical threats to biological diversity than the traditional topics.

Breininger, David R.↗
NASA NTRS1995

Radiation Propulsion For Maintaining Orbits

Brief report proposes radiative propulsion systems for maintaining precise orbits of spacecraft. Radiation from electrical heaters directed outward by paraboloidal reflectors to produce small forces to oppose uncontrolled drag and solar-radiative forces perturbing orbits. Minimizes or eliminates need to fire rocket thrusters to correct orbits.

Richter, Robert↗
NASA NTRS1992

Effects of Long-Term Daily Administration of Prostaglandin-E2 on Maintaining Elevated Proximal Tibial Metaphyseal Cancellous Bone Mass in Male Rats

The effects of long-term prostaglandin E(sub 2) (PGE(sub 2)) on cancellous bone in proximal tibial metaphysis were studied in 7 month old male Sprague-Dawley rats given daily subcutaneous injections of 0, 1, 3, and 6 mg PGE(sub 2)/kg/day and sacrificed after 60, 120, and 180 days. Histomorphometric analyses were performed on double fluorescent-labeled undecalcified bone specimens. After 60 days of treatment, PGE(sub 2) produced diffusely labeled trabecular bone area, increased trabecular bone area, eroded and labeled trabecular perimeter, mineral apposition rate, and bone formation rate at all dose levels when compared with age-matched controls. In rats given PGE(sub 2) for longer time periods (120 and 180 days), trabecular bone area, diffusely labeled trabecular bone area, labeled perimeter, mineral apposition, and bone formation rates were sustained at the elevated levels achieved earlier at 60-day treatment. The eroded perimeter continued to increase until 120 days, then plateau. The observation that continuous systemic PGE(sub 2) administration to adult male rats elevated metaphyseal cancellous bone mass to 3.5-fold of the control level within 60 days and maintained it for another 120 days indicates that the powerful skeletal anabolic effects of PGE2 can be sustained with continuous administration .

Ke, Hua Zhu↗
NASA NTRS1999

Light-Emitting Diodes and Cool White Fluorescent Light Similarly Suppress Pineal Gland Melatonin and Maintain Retinal Function and Morphology in the Rat

Currently, the light sources most commonly used in animal habitat lighting are cool white fluorescent or incandescent lamps. We evaluated a novel light-emitting diode (LED) light source for use in animal habitat lighting by comparing its effectiveness to cool white fluorescent light (CWF) in suppressing pineal gland melatonin and maintaining normal retinal physiology and morphology in the rat. Results of pineal melatonin suppression experiments showed equal suppression of pineal melatonin concentrations for LED light and CWF light at five different light illuminances (100, 40, 10, 1 and 0.1 lux). There were no significant differences in melatonin suppression between LED and CWF light when compared to unexposed controls. Retinal physiology was evaluated using electroretinography. Results show no differences in a-wave implicit times and amplitudes or b-wave implicit times and amplitudes between 100-lux LED-exposed rats and 100-lux CWF-exposed rats. Results of retinal histology assessment show no differences in retinal thickness rod outer segment length and number of rod nuclei between rats exposed to 100-lux LED and 100-lux CWF for days. Furthermore, the retinal pigmented epithelium and rod outer segments of all eyes observed were in good condition and of normal thickness. This study indicates that LED light does not cause retinal damage and can suppress pineal melatonin at similar intensities as a conventional CWF light source. These data suggest that LED light sources may be suitable replacements for conventional light sources used in the lighting of rodent vivariums while providing many mechanical and economical advantages.

Holley, Daniel C.↗
NASA NTRS1999

Pilot Performance on New ATM Operations: Maintaining In-Trail Separation and Arrival Sequencing

Cockpit Display of Traffic Information (CDTI) may enable new Air Traffic Management (ATM) operations. However, CDTI is not the only source of traffic information in the cockpit; ATM procedures may provide information, implicitly and explicitly, about other aircraft. An experiment investigated pilot ability to perform two new ATM operations - maintaining in-trail separation from another aircraft and sequencing into an arrival stream. In the experiment, pilots were provided different amounts of information from displays and procedures. The results are described.

Pritchett, Amy R.↗
NASA NTRS2000

Approximation Model Building for Reliability & Maintainability Characteristics of Reusable Launch Vehicles

This paper describes the development of parametric models for estimating operational reliability and maintainability (R&M) characteristics for reusable vehicle concepts, based on vehicle size and technology support level. A R&M analysis tool (RMAT) and response surface methods are utilized to build parametric approximation models for rapidly estimating operational R&M characteristics such as mission completion reliability. These models that approximate RMAT, can then be utilized for fast analysis of operational requirements, for lifecycle cost estimating and for multidisciplinary sign optimization.

Unal, Resit↗
NASA NTRS2001

Increased Body Weight Reduces Voluntary Movement to Maintain Energy Expenditure of Rats Exposed to Increases in Gravity

With the increase in obesity related diseases there is heightened interest in mechanisms regulating body weight. To assess the influence of increases in body weight on energy expenditure and intake in rats we employed variable levels of gravity. Our approach afforded the means to measure interactions of energy expenditure and intake in response to increases in body weight (body mass x gravity level). We found a dose relationship between rapid elevation of body weight and reduction of voluntary movement, such that the energy requirements for activity are unchanged, and total energy expenditure and intake maintained. Reduction of movement appears to be a response to increased body weight, rather than a contributing factor, suggesting a new regulatory pathway.

Wade, C. E.↗