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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 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

The Get Away Special Program

The paper deals with the Get Away Special (GAS) Program which was initiated on the realization that not every Space Shuttle mission would make full use of the volume and weight capability of the Shuttle system. Currently, the GAS Program incorporates 158 domestic and foreign users who have reserved 270 spaces. Not all users and not all experiments are expected to meet the objective of processing to prime experiments for Shuttle. Each experiment will be worthy in its own right and each user will benefit to the limit of his ability and involvement. The structure and the mounting system of the GAS container are described, along with its pressure, thermal, and electronic characteristics. Safety philosophy and requirements are noted, and possible options to the standard contained are discussed.

Ott, E. J.↗
NASA NTRS1979

The results of studies to determine the impact of far-aft center-of-gravity locations on the design of a single-stage-to-orbit vehicle system

Aft center-of-gravity locations dictated by the large number of rocket engines required has been a continuing problem of single-stage-to-orbit vehicles. Recent work at Langley has demonstrated that these aft center-of-gravity problems become more pronounced for the proposed heavy-lift mission, creating some unique design problems for both the SSTO and staged vehicle systems. During the course of this study, an effort was made to bring together automated vehicle design, wind-tunnel tests, and flight control analyses to assess the impact of longitudinal and lateral-directional instability, and control philosophy on entry vehicle design technology.

Freeman, D. C., Jr.↗
NASA NTRS1979

The dual momentum control device for large space systems - An example of distributed system adaptive control

One area in which large space systems require new technology is attitude control. The paper presents an adaptive control philosophy applicable to the control of distributed systems. An adaptive control system is described for stabilization of the flexible modes of a spinning ring. The system consists of a modal decomposition and identification subsystem, a gain adjustment subsystem, and a feedback control subsystem. Simulations are presented illustrating the adaptive capability of the system. The adaptive controller did produce stable results by quickly identifying the parameter differences and adjusting the feedback controller gains.

Montgomery, R. C.↗
NASA NTRS1979

Aerodynamic characteristics of missile configurations based on Soviet design concepts

The aerodynamic characteristics of several missile concepts are examined. The configurations, which are based on some typical Soviet design concepts, include fixed-wing missiles with either forward- or aft-tail controls, and wing-control missiles with fixed aft stabilizing surfaces. The conceptual missions include air-to-air, surface-to-air, air-to-surface, and surface-to-surface. Analytical and experimental results indicate that through the proper shaping and location of components, and through the exploitation of local flow fields, the concepts provide generally good stability characteristics, high control effectiveness, and low control hinge moments. In addition, in the case of some cruise-type missions, there are indications of the application of area ruling as a means of improving the aerodynamic efficiency. In general, a point-design philosophy is indicated whereby a particular configuration is developed for performing a particular mission.

Spearman, M. L.↗
NASA NTRS1979

Indirect adaptive stabilization of a large, flexible, spinning spacering Simulation studies

A recently formulated approach to the adaptive control of distributed systems combines the simultaneous identification and control philosophy of indirect adaptive control with a modal expansion description of distributed systems. The regulation of a large, flexible, spinning spacering, one half of a dual momentum control device proposed for attitude control of large space systems, provides the example upon which the capabilities of such a synthesis method are tested via simulation.

Hamm, A. L.↗
NASA NTRS1979

Commercial phosphoric acid fuel cell system technology development

A review of the current commercial phosphoric acid fuel cell system technology development efforts is presented. In both the electric utility and on-site integrated energy system applications, reducing cost and increasing reliability are the technology drivers at this time. The longstanding barrier to the attainment of these goals, which manifests itself in a number of ways, has been materials. The differences in approach among the three major participants (United Technologies Corporation (UTC), Westinghouse Electric Corporation/Energy Research Corporation (ERC), and Engelhard Industries) and their unique technological features, including electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, fuel selection and system design philosophy are discussed.

Prokopius, P. R.↗
NASA NTRS1976

Quiet Clean Short-haul Experimental Engine (QCSEE): Hamilton Standard cam/harmonic drive variable pitch fan actuation system detail design report

A variable pitch fan actuation system was designed which incorporates a remote nacelle-mounted blade angle regulator. The regulator drives a rotating fan-mounted mechanical actuator through a flexible shaft and differential gear train. The actuator incorporates a high ratio harmonic drive attached to a multitrack spherical cam which changes blade pitch through individual cam follower arms attached to each blade trunnion. Detail design parameters of the actuation system are presented. These include the following: design philosophies, operating limits, mechanical, hydraulic and thermal characteristics, mechanical efficiencies, materials, weights, lubrication, stress analyses, reliability and failure analyses.

Source record↗
NASA NTRS1980

Photovoltaic power system reliability considerations

An example of how modern engineering and safety techniques can be used to assure the reliable and safe operation of photovoltaic power systems is presented. This particular application is for a solar cell power system demonstration project designed to provide electric power requirements for remote villages. The techniques utilized involve a definition of the power system natural and operating environment, use of design criteria and analysis techniques, an awareness of potential problems via the inherent reliability and FMEA methods, and use of fail-safe and planned spare parts engineering philosophy.

Lalli, V. R.↗
NASA NTRS1979

Space shuttle solid rocket booster cost-per-flight analysis technique

A cost per flight computer model is described which considers: traffic model, component attrition, hardware useful life, turnaround time for refurbishment, manufacturing rates, learning curves on the time to perform tasks, cost improvement curves on quantity hardware buys, inflation, spares philosophy, long lead, hardware funding requirements, and other logistics and scheduling constraints. Additional uses of the model include assessing the cost per flight impact of changing major space shuttle program parameters and searching for opportunities to make cost effective management decisions.

Forney, J. A.↗
NASA NTRS1980

Shuttle Global Positioning (GPS) System design study

Investigations of certain aspects and problems of the shuttle global positioning system GPS, are presented. Included are: test philosophy and test outline; development of a phase slope specification for the shuttle GPS antenna; an investigation of the shuttle jamming vulnerability; and an expression for the GPS signal to noise density ratio for the thermal protection system.

Nilsen, P.↗
NASA NTRS1979

LSA field test

Degradation tests indicate that electrical degradation is not a slow monotonically increasing phenomenon as originally thought but occurs abruptly as the result of some traumatic event. This finding has led to a change in the test philosophy. A discussion of this change is presented along with a summary of degradation and failure data from all the sites and results from a variety of special tests. New instrumentation for in-field measurements are described. Field testing activity was expanded by the addition of twelve remote sites located as far away as Alaska and the Canal Zone. Descriptions of the new sites are included.

Jaffe, P.↗
NASA NTRS1979

Low-cost point-focus solar concentrator, phase 1

The results of the preliminary design study for the low cost point focus solar concentrator (LCPFSC) development program are presented. A summary description of the preliminary design is given. The design philosophy used to achieve a cost effective design for mass production is described. The concentrator meets all design requirements specified and is based on practical design solutions in every possible way.

Nelson, E. V.↗
NASA NTRS1980

Management. A continuing bibliography with indexes

This bibliography cites 604 reports, articles, and other documents introduced into the NASA scientific and technical information system in 1979 covering the management of research and development, contracts, production, logistics, personnel, safety, reliability and quality control. Program, project, and systems management; management policy, philosophy, tools, and techniques; decision making processes for managers; technology assessment; management of urban problems; and information for managers on Federal resources, expenditures, financing, and budgeting are also covered. Abstracts are provided as well as subject, personal author, and corporate source indexes.

Source record↗
NASA NTRS1980

The design and application of an antenna positioner mechanism for Intelsat-5 series communication satellite

In opertion, the East/West spot beam reflectors on the Intelsat-5 series communication satellite are required to satisfy initial precise-pointing to particular Earth locations; and repositioning and pointing to different Earth locations as traffic changes dictate during the seven year mission. Two 2 axis antenna positioner mechanisms (APM) are utilized in fulfilling these requirements. Each APM is comprised of three components which consist of one center pivot and two linear actuators rather than an integral two axis gimbal design. The step resolution of the APM can be adjusted as required with the present design, at a step resolution of 0.002865 degrees. The design philosophy and considerations, test program, and test results are discussed as well as some major problems encountered during the course of testing and their resolution.

Szeto, B.↗
NASA NTRS1980

Ground/bonding for Large Space System Technology (LSST)

The influence of the environment and extravehicular activity remote assembly operations on the grounding and bonding of metallic and nonmetallic structures is discussed. Grounding and bonding philosophy is outlined for the electrical systems and electronic compartments which contain high voltage, high power electrical and electronic equipment. The influence of plasma and particulate on the system was analyzed and the effects of static buildup on the spacecraft electrical system discussed. Conceptual grounding bonding designs are assessed for capability to withstand high current arcs to ground from a high voltage conductor and electromagnetic interference. Also shown were the extravehicular activities required of the space station and or supply spacecraft crew members to join and inspect the ground system using manual on remote assembly construction.

Dunbar, W. G.↗
NASA NTRS1980

BIRP: Software for interactive search and retrieval of image engineering data

Better Image Retrieval Programs (BIRP), a set of programs to interactively sort through and to display a database, such as engineering data for images acquired by spacecraft is described. An overview of the philosophy of BIRP design, the structure of BIRP data files, and examples that illustrate the capabilities of the software are provided.

Arvidson, R. E.↗