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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Extravehicular Crewman Work System (ECWS) study program. Volume 1: Executive summary

The Extravehicular Crewman Work System (ECWS) requirements for manned support of space construction and satellite service are defined. Characteristics of structures and satellites are described. Requirements for extravehicular tasks and support equipment are defined. Equipment concepts are presented and evaluated for extravehicular life support, spacesuit, and work aids. Preliminary design of recommended ECWS equipment concepts and new technology developments required for their implementation are discussed.

Wilde, R. C.↗
NASA NTRS1980

Critical currents in A-15 structure Nb3Al converted from cold-worked bcc structure

The paper considers critical currents in A-15 structure Nb3Al converted from a cold-worked bcc structure. Nb3Al prepared in the ductile phase by quenching and mechanical working followed by conversion to the A-15 structure could carry currents above 10 to the 9th power A/sq m in fields near 20 T. These critical currents are comparable to those of Nb3Ge and V3Ga which are closest competing materials for use in high fields; further enhancement of the critical current is possible if thermal treatments are optimized.

Woollam, J. A.↗
NASA NTRS1982

Work Station For Inverting Solar Cells

Final work station along walking-beam conveyor of solar-array assembly line turns each pretabbed solar cell over, depositing it back-side-up onto landing pad, which centers cell without engaging collector surface. Solar cell arrives at inverting work station collector-side-up with two interconnect tabs attached to collector side. Cells are inverted so that second soldering operation takes place in plain view of operator. Inversion protects collector from damage when handled at later stages of assembly.

Feder, H.↗
NASA NTRS1980

First Scientific Working Group Meeting of Airborne Doppler Lidar Wind Velocity Measurement Program

The purpose of the first scientific working group meeting was fourfold: (1) to identify flight test options for engineering verification of the MSFC Doppler Lidar; (2) to identify flight test options for gathering data for scientific/technology applications; (3) to identify additional support equipment needed on the CV 990 aircraft for the flight tests; and (4) to identify postflight data processing and data sets requirements. The working group identified approximately ten flight options for gathering data on atmospheric dynamics processes, including turbulence, valley breezes, and thunderstorm cloud anvil and cold air outflow dynamics. These test options will be used as a basis for planning the fiscal year 1981 tests of the Doppler Lidar system.

Kaufman, J. W.↗
NASA NTRS1980

Science Requirements Working Group (SRWG) in float zone materials processing in space: A review

A summary and history of the Float Zone Working Group was presented. The functions of this working group are to: provide an informal forum of scientific investigators for the exchange of information and ideas in the approach of the solution of common problems in float zone processing, help plan the research and development necessary to place the float zone process on a firm base of scientific understanding and advanced technological development, establish the science requirements for the AFZES for Spacelab, and seek ways to maximize the advantages of the space environment in the pursuit of these goals.

Fowle, A. A.↗
NASA NTRS1981

The horizontal and vertical semi-diameters of the Sun observed at the Cape of Good Hope (1834 - 1887) and Paris (1837 - 1906): A report on work in progress

Cape and Paris meridian observations of the solar limbs which permit an estimate to be made of the solar semi-diameter were surveyed, sampled, and compared with Greenwich and U.S. Naval Observatory observations. Significant systematic errors were found in the Paris work and have been correlated with changes of instruments and observers. Results from the Cape series indicate that work should continue on the compilation of data from Cape observations of the Sun.

Smith, C.↗
NASA NTRS1982

Work of fracture in aluminum metal-matrix composites

Mechanical tests were conducted on B/Al composites and, for comparison, FP-Al2O3/Al composites in the as-fabricated condition and following high-temperature isothermal exposure or thermal cycling. In B/Al (1100), isothermal exposure at 773 K for 125 hr reduced toughness, measured by the work of fracture, from 76 to 10 kJ/sq m, and a similar reduction was observed after equivalent thermal cycling. In B/Al (6061), the same isothermal exposure reduced toughness from 44.5 to 8 kJ/sq m, but the effect of thermal cycling was less detrimental. In FP-Al2O3/Al, the work of fracture was insensitive to either type of treatment. Experimental results are interpreted in terms of matrix softening, interface properties, and fiber notch sensitivity.

Skinner, A.↗
NASA NTRS1983

A mobile work station concept for mechanically aided astronaut assembly of large space trusses

This report presents results of a series of truss assembly tests conducted to evaluate a mobile work station concept intended to mechanically assist astronaut manual assembly of erectable space trusses. The tests involved assembly of a tetrahedral truss beam by a pair of test subjects with and without pressure (space) suits, both in Earth gravity and in simulated zero gravity (neutral buoyancy in water). The beam was assembled from 38 identical graphite-epoxy nestable struts, 5.4 m in length with aluminum quick-attachment structural joints. Struts and joints were designed to closely simulate flight hardware. The assembled beam was approximately 16.5 m long and 4.5 m on each of the four sides of its diamond-shaped cross section. The results show that average in-space assembly rates of approximately 38 seconds per strut can be expected for struts of comparable size. This result is virtually independent of the overall size of the structure being assembled. The mobile work station concept would improve astronaut efficiency for on-orbit manual assembly of truss structures, and also this assembly-line method is highly competitive with other construction methods being considered for large space structures.

Heard, W. L., Jr.↗
NASA NTRS1982

The Multispectral Imaging Science Working Group. Volume 1: Executive summary

Results of the deliberations of the six multispectral imaging science working groups (Botany, Geography, Geology, Hydrology, Imaging Science and Information Science) are summarized. Consideration was given to documenting the current state of knowledge in terrestrial remote sensing without the constraints of preconceived concepts such as possible band widths, number of bands, and radiometric or spatial resolutions of present or future systems. The findings of each working group included a discussion of desired capabilities and critical developmental issues.

Cox, S. C.↗
NASA NTRS1985

Report from the Cavity-Laser Working Group

From the Workshop, a Cavity-Laser Working Group was formed. The goal of this Cavity-Laser Working Group was to propose molecules which might be useful as lasants for blackbody cavity lasers. The approach was to (1) define some rules for the identification of molecules, (2) consider molecules presented at the Workshop and (3) identify additional molecules through the suggestions of attendees. Some evaluation was to be attempted for each molecule considered. A set of criteria was developed, however, sophisticated rules required detailed information which was not available for every molecule. The rules are listed and briefly discussed.

Conway, E. J.↗
NASA NTRS1985

Working group on chromospheric fields - Canopies

Although there are many points of uncertainty and controversy, the working group on chromospheric fields focussed its discussion on the concept of canopies; i.e., no one disagreed that a central issue relating to magnetic fields and chromospheric models is to learn how the photospheric field spreads with height. However, it quickly became apparent that in the time available, there was little prospect of building new unified models of magnetic field phenomena in the chromosphere beyond the scope of the formal presentations. Thus, the discussion was devoted to formulating questions which seemed both possible to address in future work and important for advancing understanding of the chromosphere. It began by discussing unresolved physical issues (almost everything) and then proceeded to consider means, both observational and synthetic, to address them.

Jones, H. P.↗
NASA NTRS1986

Large structures and tethers working group

The Large Structures and Tethers Working Group sought to clarify the meaning of large structures and tethers as they related to space systems. Large was assumed to mean that the characteristic length of the structure was greater than one of such relevant plasma characteristics as ion gyroradius or debey length. Typically, anything greater than or equal to the Shuttle dimensions was considered large. It was agreed that most large space systems that the tether could be better categorized as extended length, area, or volume structures. The key environmental interactions were then identified in terms of these three categories. In the following Working Group summary, these categories and the related interactions are defined in detail. The emphasis is on how increases in each of the three spatial dimensions uniquely determine the interactions with the near-Earth space environment. Interactions with the environments around the other planets and the solar wind were assumed to be similar or capable of being extrapolated from the near-Earth results. It should be remembered in the following that the effects on large systems do not just affect specific technologies but will quite likely impact whole missions. Finally, the possible effects of large systems on the plasma environment, although only briefly discussed, were felt to be of potentially great concern.

Murphy, G.↗
NASA NTRS1986

Working group report on advanced high-voltage high-power and energy-storage space systems

Space systems in the future will probably include high-voltage, high-power energy-storage and -production systems. Two such technologies are high-voltage ac and dc systems and high-power electrodynamic tethers. The working group identified several plasma interaction phenomena that will occur in the operation of these power systems. The working group felt that building an understanding of these critical interaction issues meant that several gaps in our knowledge had to be filled, and that certain aspects of dc power systems have become fairly well understood. Examples of these current collection are in quiescent plasmas and snap over effects. However, high-voltage dc and almost all ac phenomena are, at best, inadequately understood. In addition, there is major uncertainty in the knowledge of coupling between plasmas and large scale current flows in space plasmas. These gaps in the knowledge are addressed.

Cohen, H. A.↗
NASA NTRS1986

Manned Mars missions: A working group report

The discussions of the Working Group (based in large part on working papers, which will shortly be published separately) are summarized. These papers cover a broad range of subjects which need to be addressed in the formulation of such a formidable enterprise as a manned Mars program. Science objective and operations; Mars surface infrastructure and activities; mission and system concepts and configurations; life sciences; impacts on the space infrastructure; and costs, schedules, and organizations are addressed.

Duke, Michael B.↗
NASA NTRS1987

Telerobotic work system: Concept development and evolution

The basic concept of a telerobotic work system (TWS) consists of two dexterous manipulator arms controlled from a remote station. The term telerobotic describes a system that is a combination of teleoperator control and robotic operation. Work represents the function of producing physical changes. System describes the integration of components and subsystems to effectively accomplish the needed mission. Telerobotics reduces exposure to hazards for flight crewmembers and increases their productivity. The requirements for the TWS are derived from both the mission needs and the functional capabilities of existing hardware and software to meet those needs. The development of the TWS is discussed.

Jenkins, Lyle M.↗
NASA NTRS1988

Cold-Worked Inconel(R) 718 Bars

Cold working and double aging yield high strength without sacrifice of resistance to corrosion. Report presents data on mechanical properties and stress-corrosion resistance of triple-melted, solution-treated, work-strengthened, direct-double-aged Inconel(R) 718 alloy. Triple melting consists of vacuum induction melting, electro-slag remelting, and vacuum arm remelting. Data indicate advance in processing of large-diameter bars. New process increases yield strength without reducing the elongation, reduction of area, and grain size.

Montano, J. W.↗
NASA NTRS1987

Report from the MPP Working Group to the NASA Associate Administrator for Space Science and Applications

NASA's Office of Space Science and Applications (OSSA) gave a select group of scientists the opportunity to test and implement their computational algorithms on the Massively Parallel Processor (MPP) located at Goddard Space Flight Center, beginning in late 1985. One year later, the Working Group presented its report, which addressed the following: algorithms, programming languages, architecture, programming environments, the way theory relates, and performance measured. The findings point to a number of demonstrated computational techniques for which the MPP architecture is ideally suited. For example, besides executing much faster on the MPP than on conventional computers, systolic VLSI simulation (where distances are short), lattice simulation, neural network simulation, and image problems were found to be easier to program on the MPP's architecture than on a CYBER 205 or even a VAX. The report also makes technical recommendations covering all aspects of MPP use, and recommendations concerning the future of the MPP and machines based on similar architectures, expansion of the Working Group, and study of the role of future parallel processors for space station, EOS, and the Great Observatories era.

Fischer, James R.↗