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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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

The manned maneuvering unit flight controller arm

The Manned Maneuvering Unit (MMU) and its support equipment provide an extravehicular astronaut mobility, and the ability to work outside the confines of the Shuttle Orbiter payload bay. The MMU design requirements are based on the highly successful Skylab M-509 maneuvering unit. Design of the MMU was started as an R&D effort in April 1975 and Flight Hardware design was started in August 1979 to support a possible requirement for in-space inspection and repair of Orbiter thermal protection tiles. Subsequently, the qualification test and production activities were slowed, and the current projected earliest first flight is now STS-11 in January, 1984. The MMU propulsion subsystem provides complete redundancy with two identical "system". Each system contains a high pressure gaseous nitrogen tank, an isolation valve, a regulator, and twelve 1.7 lbf (7.5 N) thrusters. The thrusters are packaged to provide the crew member six-degree-of-freedom control in response to commands from translational and rotational hand controllers. This paper discusses the MMU control arm requirements, design, and developmental history.

Falkner, K. E.↗
NASA NTRS1983

Space Shuttle Orbiter Leading Edge Structural Subsystem development

The development of the Space Shuttle Orbiter Leading Edge Structural Subsystem (LESS) is traced from concept definition, through technical development, to final design, qualification testing and flight performance. A detailed description of the LESS is presented to support a discussion of the design, material development and thermal/structural integration. Extensive development/qualification tests and analytical studies were performed to verify the thermal/structural system performance and to certify the LESS for flight. Flight data and detailed post-flight inspection results are presented which support the conclusion that the LESS system performance has been outstanding.

Curry, D. M.↗
NASA NTRS1983

Evaluation of nickel-hydrogen battery for space application

Results of electrical space qualification tests of nickel-hydrogen battery type HR 23S are presented. The results obtained for the nickel-cadmium battery type VO 23S are similar except that the voltage level and the charge conservation characteristics vary significantly. The electrical and thermal characteristics permit predictions of the following optimal applications: charge coefficient in the order of 1.3 to 1.4 at 20C; charge current density higher than C/10 at 20C; discharge current density from C/10 to C/3 at 20C; maximum discharge temperature: OC; storage temperature: -20C.

Billard, J. M.↗
NASA NTRS1984

Operational Experience from Solar Thermal Energy Projects

Over the past few years, Sandia National Laboratories were involved in the design, construction, and operation of a number of DOE-sponsored solar thermal energy systems. Among the systems currently in operation are several industrial process heat projects and the Modular Industrial Solar Retrofit qualification test systems, all of which use parabolic troughs, and the Shenandoah Total Energy Project, which uses parabolic dishes. Operational experience has provided insight to both desirable and undesirable features of the designs of these systems. Features of these systems which are also relevant to the design of parabolic concentrator thermal electric systems are discussed. Other design features discussed are system control functions which were found to be especially convenient or effective, such as local concentrator controls, rainwash controls, and system response to changing isolation. Drive systems are also discussed with particular emphasis of the need for reliability and the usefulness of a manual drive capability.

Cameron, C. P.↗
NASA NTRS1984

Characterization of 8-cm engineering model thruster

Development of 8 cm ion thruster technology which was conducted in support of the Ion Auxiliary Propulsion System (IAPS) flight contract (Contract NAS3-21055) is discussed. The work included characterization of thruster performance, stability, and control; a study of the effects of cathode aging; environmental qualification testing; and cyclic lifetesting of especially critical thruster components.

Williamson, W. S.↗
NASA NTRS1985

X-ray satellite

The projected launch date has been delayed approx. 7 weeks from the planned launch date. The Engineering Model (EM) of the automatic measurement and control system (AMCS) is in the critical phase. The contract change no. 1 to the main contract has been signed. A new version of the welding seam location specifications for the wide field camera (WFC) was proposed by the WFC Consortium. The payload integration plan (PIP) has been signed. Production of the EM/QM prototype and ground station equipment has proceeded according to plan with the exception of some delays. Production of the EM equipment has begun. Preparations for the qualification tests of the EM/QM equipment and the integration of EM equipment has begun. The cause of the delay in the launch date include the combined effects of the postponement of the target date for the EM equipment, along with the fact that only a structural model is available.

Source record↗
NASA NTRS1985

The Hopkins ultraviolet telescope

The Shuttle is scheduled to carry the Hopkins UV Telescope (HUT) aloft in 1986. HUT will be one of three telescopes on the mission and will be sensitive to the 450-1800 A interval. Its primary goals will be observations of Halley's Comet, the planets, distant galaxies and quasars. It will be controlled by Spacelab personnel and features a 0.9 m primary mirror, a spectrograph on the focal plane, and an Si intensified image television camera for on-line image monitoring. The main component of the spectrograph will be a 1024 channel self-scanning Reticon photodiode array coupled by optic fibers to the microchannel detector plates. HUT is presently undergoing qualification testing.

Davidsen, A. F.↗
NASA NTRS1984

Equivalent electron fluence for space qualification of shallow junction heteroface GaAs solar cells

It is desirable to perform qualification tests prior to deployment of solar cells in space power applications. Such test procedures are complicated by the complex mixture of differing radiation components in space which are difficult to simulate in ground test facilities. Although it has been shown that an equivalent electron fluence ratio cannot be uniquely defined for monoenergetic proton exposure of GaAs shallow junction cells, an equivalent electron fluence test can be defined for common spectral components of protons found in space. Equivalent electron fluence levels for the geosynchronous environment are presented.

Wilson, J. W.↗
NASA NTRS1985

Modification of the Electromagnetic Levitator (EML) Hardware

The goals of this project are: (1) to study the upgrade requirements and approaches needed for incorporation of an Electromagnetic Levitator (EML) into the shuttle orbiter, (2) to work with members of the Electromagnetic Containerless Processing science working group (SWG) to define future experiments for the EML, and (3) to assist these investigators in further development of ground-based experiment techniques to the limits possible in the terrestrial gravitational environment. Present work is directed toward: (1) upgrading the EML flight apparatus to meet requirements of safety and integration interfaces with the MSL orbiter carrier, (2) development of new experiment components required to carry out approved experiments in undercooled solidification and associated fluid flow studies directed by MIT, and (3) construction, test, qualification and integration assistance for the EML MSL flight package.

Frost, R. T.↗
NASA NTRS1986

Crystalline-silicon photovoltaics summary module design and reliability

The evolution of the design and reliability of solar modules was described. Design requirements involved 14 different considerations, including residential building and material electrical codes, wind-loading, hail impact, operating temperature levels, module flammability, and interfaces for both the array structure and the operation of the system. Reliability research involved in diverse investigations including glass-fracture strength, soiling levels, electrochemical corrosion, and bypass-diode qualification tests. Based on these internationally recognized studies, performance assessments, and failure analyses, the Flat-plate Solar Array Project in its 11-year duration served to nuture the development of 45 different solar module designs from 15 PV manufacturers.

Ross, R. G., Jr.↗
NASA NTRS1986

Long-term stability of amorphous-silicon modules

The Jet Propulsion Laboratory (JPL) program of developing qualification tests necessary for amorphous silicon modules, including appropriate accelerated environmental tests reveal degradation due to illumination. Data were given which showed the results of temperature-controlled field tests and accelerated tests in an environmental chamber.

Ross, R. G., Jr.↗
NASA NTRS1987

Design and initial application of the extended aircraft interrogation and display system: Multiprocessing ground support equipment for digital flight systems

A pipelined, multiprocessor, general-purpose ground support equipment for digital flight systems has been developed and placed in service at the NASA Ames Research Center's Dryden Flight Research Facility. The design is an outgrowth of the earlier aircraft interrogation and display system (AIDS) used in support of several research projects to provide engineering-units display of internal control system parameters during development and qualification testing activities. The new system, incorporating multiple 16-bit processors, is called extended AIDS (XAIDS) and is now supporting the X-29A forward-swept-wing aircraft project. This report describes the design and mechanization of XAIDS and shows the steps whereby a typical user may take advantage of its high throughput and flexible features.

Glover, Richard D.↗
NASA NTRS1985

Fiber optic data systems

An overview is given of a continuing data system architecture development effort. Accomplishments and states of Office of Aeronautics and Space Technology, NASA efforts are discussed, and possible future directions are briefly commented upon. Some performance data is presented on the access protocol utilized in the Bus Interface Unit (BIU) design effort, and it is compared with other access protocols. The status of the qualification effort is presented showing the successful qualification testing of cables, connectors, light emitting diodes and PIN diodes. Information is given in the form of charts and diagrams.

Hartenstein, R.↗
NASA NTRS1987

A view from the AIAA: Introduction of new energy storage technology into orbital programs

The development of new energy storage technology must be heavily weighted toward the application. The requirements for transitioning low risk technology into operational space vehicles must remain the central theme even at the preliminary development stages by the development of efforts to define operational issues and verify the reliability of the system. Failure to follow a complete plan that results in a flight qualified unit may lead to an orphan technology. Development efforts must be directed toward a stable development where changes in design are evolutionary and end items are equivalent to flight units so that life and qualification testing can be used as a vehicle to demonstrate the acceptability of the technology.

Badcock, Charles↗
NASA NTRS1985

Evaluation of load tracks and wear of two sets of bearings from space shuttle main engine high pressure oxygen turbopumps

Bearings supporting the rotor in the High Pressure Oxygen Turbopump (HPOTP) were examined. The No. 1 bearings from both units were in good condition and had successfully completed 5000 seconds of operation. The No. 2 bearings, which were in service the same length of time, were significantly degraded in the form of ball wear, race pitting, and damage from high axial loads. The No. 3 and 4 bearings were in generally acceptable condition. The general conclusion from the examinations was that improved cooling on the No. 2 bearings and further improvements in controlling axial and radial load would likely result in the HPOTP meeting the qualification test results.

Kannel, J. W.↗
NASA NTRS1988

Development of subminiature multi-sensor hot-wire probes

Limitations on the spatial resolution of multisensor hot wire probes have precluded accurate measurements of Reynolds stresses very near solid surfaces in wind tunnels and in many practical aerodynamic flows. The fabrication, calibration and qualification testing of very small single horizontal and X-array hot-wire probes which are intended to be used near solid boundaries in turbulent flows where length scales are particularly small, is described. Details of the sensor fabrication procedure are reported, along with information needed to successfully operate the probes. As compared with conventional probes, manufacture of the subminiature probes is more complex, requiring special equipment and careful handling. The subminiature probes tested were more fragile and shorter lived than conventional probes; they obeyed the same calibration laws but with slightly larger experimental uncertainty. In spite of these disadvantages, measurements of mean statistical quantities and spectra demonstrate the ability of the subminiature sensors to provide the measurements in the near wall region of turbulent boundary layers that are more accurate than conventional sized probes.

Westphal, Russell V.↗
NASA NTRS1988

Optimal solutions for complex design problems: Using isoperformance software for human factors trade offs

A major application of isoperformance is as a trade-off methodology of the three major drivers of system design; equipment, training variables, and user characteristics. The flexibility of isoperformance allows each of these three components to be nearly any rational variation. For example, aptitude may be military Armed Forces Qualification Testing (AFQT) categories, cutoff scores within a selection procedure, or simply dichotomizing high and low scorers (pass/fail). Equipment may be new versus old, 'smart' versus dumb, high versus low resolution, etc. Training may be short versus long or varieties of media types (lecture versus CAI/CBI versus self-paced workbooks). In its final computerized form isoperformance lets the user set an operational level of performance (e.g., a jet pilot in a simulated emergency must take prescribed corrective action and clear the plane in several seconds, pilot astronauts will check out all shuttle flight systems within 30 minutes, or Mission Specialists must handle sucdessfully a required number of job elements). At this point the computer program guides the user through any requested trade-offs of the three components while maintaining the specified operational level of performance through isoperformance curves. A demonstration of the computer program is currently available.

Kennedy, Robert S.↗
NASA NTRS1989

Qualification of improved joint heaters

Qualification testing of the Redesigned Solid Rocket Motor improved igniter-to-case joint and field joint heaters was conducted on the fired TEM-04 static test motor and was completed on 7 Sep. 1989. The purpose of the test was to certify the installation and performance of the improved joint heaters for use on flight motors. The changes incorporated in the improved heaters improve durability and should reduce handling damage. The igniter-to-case joint and field joint primary heater circuits were subjected to five 20-hr ON cycles. The heater redundant circuits were then subjected to one 20-hr ON cycle. Voltage, current, and temperature set point values were maintained within the specified limits for both heaters during each ON cycle. When testing was complete, both heaters were removed and inspected. No discolorations or any other anomalies were found on either of the heaters. Based on the successful completion of this test, it is recommended that the improved igniter-to-case joint and field joint heaters be used on future flight motors.

Cook, M.↗