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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1970

Hypersonic Research Facilities Study - Volume IV, Part 1: Phase III Final Studies Flight Research Facilities

The Phase III analyses of Flight Research Facilities performed as a portion of the Hypersonic Research Facilities (HYFAC) Study are presented herein. Two attractive flight research vehicle concepts, geared to the development needs of future (1980-2n00) operational hypersonic aircraft systems, are defined. The inherent research capability of each concept is further expanded by incorporating provisions within the basic vehicle design to accommodate the testing of several additional research options. The design feasibility of this approach to achieving increased research flexibility is examined. Near term propulsion systems are employed as the basic power plants to shorten acquisition time, reduce development costs, and provide high confidence in attaining the performance capability desired, Performance is determined for each basic vehicle and for the vehicles when incorporating several optional research packages. Total program cost estimates are developed for each vehicle and for the various research options. This study provides the necessary framework for the formulation of an attractive and needed flight research program which is a key element in the systematic development of an overall advanced research plan.

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NASA NTRS1971

Space qualified Nd:YAG laser (phase 1 - design)

Results of a design study and preliminary design of a space qualified Nd:YAG laser are presented. A theoretical model of the laser was developed to allow the evaluation of the effects of various parameters on its performance. Various pump lamps were evaluated and sum pumping was considered. Cooling requirements were examined and cooling methods such as radiation, cryogenic and conductive were analysed. Power outputs and efficiences of various configurations and the pump and laser lifetime are discussed. Also considered were modulation and modulating methods.

Foster, J. D.↗
NASA NTRS1971

Test and evaluation of Apollo 14 composite casting demonstration specimens 6, 9, and 12, phase 1

Flight and control specimens 6, 9, and 12 from the Apollo 14 composite casting demonstration were evaluated with respect to the degree of dispersion achieved for mixtures of immiscible materials under one-gravity and low gravity environments. The flight and control capsules 6, 9, and 12 contained paraffin and sodium acetate; paraffin, sodium acetate and argon; and paraffin, sodium acetate and 100 micrometer diameter tungsten microspheres, respectively. The evaluation and documentation utilized photographic and microstructure examinations, density measurements, and droplet size and distribution determinations. In addition, theoretical analyses were performed in order to aid in the understanding of the fluid behavior of the specimens during processing and subsequent solidification. A comparison of evaluated data with the theoretical analyses reveals that although the immiscible materials were uniquely dispersed in a low gravity environment, nonuniform dispersions were obtained primarily due to insufficient initial mixing and an essentially unidirectional thermal gradient during cooldown.

Reger, J. L.↗
NASA NTRS1971

VHF Ranging and Position Fixing Experiment Using ATS Satellites: Final Report on Phases 1 and 2, 25 November 1968 - 1 May 1971

The testing program with the ATS-1 and ATS-3 spacecraft showed that geostationary satellites can provide superior communications and position surveillance for mobile craft. Inexpensive modifications to conventional mobile communications equipment aboard the craft can provide reliable, high quality voice and digital communications with distant ground stations and other vehicles, and automatic surveillance of the positions of all the craft by a ground facility. The tests also demonstrated the location and automatic readout of remote data collection platforms. Frequency modulation signals with the narrow audio and radio frequency bandwidths of terrestrial mobile radio communications were relayed through the VHF transponders of the geostationary satellites. The voice and digital communications were far superior in reliability and quality to long-distance mobile communications by other means. It was shown that one satellite can provide nearly uniform high quality performance over approximately one-third of the earth's surface. Position fixes by range measurement from the two satellites were accurate to approximately one nautical mile, except near the equator and the poles.

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NASA NTRS1971

VHF ranging and position fixing experiment using ATS satellites: Executive summary of final report on phases 1 and 2, 25 November - 1 May 1971

The VHF transponders of the ATS-1 and ATS-3 geostationary satellites were used in ranging and position fixing experiments. An interrogation signal was transmitted from a ground terminal to ATS-3, which relayed it to the vehicle transponders. The vehicle that was addressed repeated the signal and its response was relayed back through both satellites to the ground terminal, where propagation times were measured; lines-of-position and fixes were computed. The 0.43 second tone-code ranging signal contained a single audio tone frequency. Ambiguity was resolved and user craft identified by a simple digital code. Seven vehicles were used in the test: three aircraft, two ships, an oceanographic buoy, and a truck. Ionospheric and multipath effects were studied. It is concluded that a VHF system could have an accuracy of + or - one nautical mile for ships and aircraft if calibration transponders are used to monitor the ionosphere.

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NASA NTRS1971

Development of lightweight graphite/polyimide honeycomb. Phase 1: Materials selection

The materials selected for the production of extremely lightweight honeycomb sandwich panels are discussed. The resin selected for the first core and face sheet fabrication was Monsanto RS6234 polyimide. The fiber selected for core manufacture was Hercules HT-S, and for face sheets, Hercules HM-S; these selections are discussed.

Poesch, J. G.↗
NASA NTRS1970

Pyrotechnic hazards classification and evaluation program. Electrostatic vulnerability of the E8 and XM15/XM165 clusters, phase 1

A survey of the electrostatic vulnerability of explosive manufacturing plants and recommendations for reducing the vulnerability are discussed. During the course of the investigations, the XM15/XM165 and the E8 launcher were shown to be susceptible to electrostatic ignition. The pyrotechnic hazard of prime concern associated with electrostatics is that of the spark which can be generated. The heat, shock, and ionization produced by the spark can cause ignition of pyrotechnics. However, as a result of the initial ignition tests (XM15 fuse train), changes have been incorporated to make the fusing system relatively safe from premature electrostatic activation.

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NASA NTRS1972

Solid state ku-band power amplifiers, phase 1

A proposed solid-state K sub u-band power amplifier utilizing a circularly symmetric array of IMPATT diodes mounted in a single radial line power combiner is discussed and its performance predicted. The proposed amplifier configuration consists of a TM sub 030 mode radial line cavity containing 20 IMPATT diodes, with separate input and output ports provided by a ferrite circulator. Conventional IMPATT amplifier techniques preclude the achievement of gain, power output, efficiency, and IMP suppression specifications simultaneously; there fore, several novel techniques with the potential of reducing the intermodulation product level are discussed.

Cohn, M.↗
NASA NTRS1970

Study of techniques for redundancy verification without disrupting systems, phases 1-3

The problem of verifying the operational integrity of redundant equipment and the impact of a requirement for verification on such equipment are considered. Redundant circuits are examined and the characteristics which determine adaptability to verification are identified. Mutually exclusive and exhaustive categories for verification approaches are established. The range of applicability of these techniques is defined in terms of signal characteristics and redundancy features. Verification approaches are discussed and a methodology for the design of redundancy verification is developed. A case study is presented which involves the design of a verification system for a hypothetical communications system. Design criteria for redundant equipment are presented. Recommendations for the development of technological areas pertinent to the goal of increased verification capabilities are given.

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