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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 271 records · Page 15

Small Transport Aircraft Technology

The article surveys the results of the NASA-instituted Small Transport Aircraft Technology (STAT) research effort aimed at generating advanced technologies for application to new small, short haul transports having significantly better performance, efficiency, and environmental compatibility. Discussion covers fuselage designs and bonded aluminum-honeycomb wing construction which reduces the number of parts and fasteners, and gives a smoother outer contour. Topics discussed include: advanced aluminum alloys, composite primary structures, propellers, engine components, icing protection, avionics, flight controls, aerodynamics, and gust load alleviation.

Galloway, T. L.↗

Automated system for integration and display of physiological response data

The system analysis approach was applied in a study of physiological systems in both 1-g and weightlessness, for short and long term experiments. A whole body, algorithm developed as the first step in the construction of a total body simulation system is described and an advanced biomedical computer system concept including interactive display/command consoles is discussed. The documentation of the design specifications, design and development studies, and user's instructions (which include program listings) for these delivered end-terms; the reports on the results of many research and feasibility studies; and many subcontract reports are cited in the bibliography.

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Model experience in the Langley 0.3-m transonic cryogenic tunnel

The model building, development, and testing experience gained during 8 years of operation of the 0.3-m Transonic Cryogenic Tunnel (TCT) is summarized. The summary is divided into four portions: (1) models tested in the 0.3-m TCT's original octagonal test section; (2) models tested in the present two dimensional test section; (3) models tested as a part of tunnel calibration and the development of advanced technology airfoils; and (4) development of a new way to construct two dimensional airfoil models. Design requirements imposed on the models by high Reynolds number testing at cryogenic temperatures are reviewed.

Lawing, P. L.↗

Advanced stress analysis methods applicable to turbine engine structures

Advanced stress analysis methods applicable to turbine engine structures are investigated. Constructions of special elements which containing traction-free circular boundaries are investigated. New versions of mixed variational principle and version of hybrid stress elements are formulated. A method is established for suppression of kinematic deformation modes. semiLoof plate and shell elements are constructed by assumed stress hybrid method. An elastic-plastic analysis is conducted by viscoplasticity theory using the mechanical subelement model.

Pian, T. H. H.↗

Development of an Advanced Trapezoidal Axially Grooved (ATAG) heat pipe

This paper discusses the breadboard development of an Advanced Trapezoidal Axially Grooved (ATAG) heat pipe, which will satisfy space constructible radiator heat rejection requirements for large space power systems. The ATAG heat pipe development program includes a technology demonstration of Space Station heat load and temperature requirements through the design, fabrication, and testing of breadboard and preprototype units. A parametric analysis was conducted to determine trapezoidal groove geometries that could meet the transport performance goal and could be fabricated by available extrusion technology for a diameter chosen to be compatible with an existing development test unit of a cylindrical, pressure-actuated contact heat exchanger. Performance test results for the breadboard heat pipes are presented.

Richter, R. F. G.↗

Design optimization of the 34-meter DSN-NCP antennas

The new NASA Deep Space Network (DSN) 34-m-diameter azimuth-elevation (Az-El) antenna structure is an example of an essentially computer-automated design. In addition to pivotal comptuer Lagrange multiplier design optimization software, much of the associated pre- and post-processing was also performed by computer. The construction of one of these antennas at Goldstone, California, is well advanced and will be completed this summer. A second installation is in progress in Australia. Both atennas will be used primarily for spacecraft tracking and will operate in the 8.5-GHz, 3.5-cm (1.4-in.) wavelength microwave frequency.

Levy, R.↗

A bootstrap lunar base: Preliminary design review 2

A bootstrap lunar base is the gateway to manned solar system exploration and requires new ideas and new designs on the cutting edge of technology. A preliminary design for a Bootstrap Lunar Base, the second provided by this contractor, is presented. An overview of the work completed is discussed as well as the technical, management, and cost strategies to complete the program requirements. The lunar base design stresses the transforming capabilities of its lander vehicles to aid in base construction. The design also emphasizes modularity and expandability in the base configuration to support the long-term goals of scientific research and profitable lunar resource exploitation. To successfully construct, develop, and inhabit a permanent lunar base, however, several technological advancements must first be realized. Some of these technological advancements are also discussed.

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Issues in the development of a 10 MBPS K=15 Viterbi decoder

The NMSU Telemetry Center, in collaboration with the NASA Microelectronics Center (MRC) at UNM, has completed a study of the feasibility of building a constraint length 15, rate 1/2 Viterbi Decoder (or BVD) to operate at a rate of 10 Mbps. The BVD, if built, would make TDRSS more accessible to all users, small satellites in particular, by providing an additional 2 dB of link margin, relative to the use of the standard constraint length 7 decoder. The study included the following: review of the 1 Mbps BVD built by the Jet Propulsion Laboratory (JPL), currently the only BVD in existence; development of Specifications for the basic processing unit of the BVD (MRC); analytical Determination of performance of large constraint length convolutional codes; investigation of the impact of processor design on the overall system design; and two feasible packaging technologies, proposed by Cincinnati Electronics of Ohio. It was concluded that while the construction of the BVD is feasible, it will require the most advanced packaging technology currently available, and that the project would be best accomplished in an industrial facility. While the size, complexity, and power requirements of the BVD will be extreme, these will impact only the ground station. The spacecraft will incur a minor change in the encoder design, and the increased coding gain will allow a satellite to operate with a smaller antenna.

Osborne, William P.↗

Analysis of selected compression splice joint locations in a graphite-epoxy transport wing stub box

Three critical compression splice joint locations in a stitched graphite-epoxy transport wing stub box have been analyzed to determine their expected structural performance. The wing box is representative of a section of a commercial transport wing box and was designed and constructed by McDonnell Douglas Aerospace Company as part of the NASA Advanced Composites Technology (ACT) program. The results of the finite element analyses of the splice joints are presented. The analysis results indicate that failure will not occur in the splice joint regions for loads less than the Design Ultimate Load of the wing box.

Jegley, Dawn C.↗

Structural Test Documentation and Results for the McDonnell Douglas All-Composite Wing Stub Box

The results of a series of tests conducted at the NASA Langley Research Center to evaluate the behavior of an all-composite full-scale wing box are presented. The wing stub box is representative of a section of a commercial transport aircraft wing box and was designed and constructed by McDonnell Douglas Aerospace Company as part of the NASA Advanced Composites Technology (ACT) program. Tests were conducted with and without low-speed impact damage and repairs. The structure with nonvisible impact damage carried 140 percent of Design Limit Load prior to failure through an impact site.

Jegley, Dawn C.↗

Contour Mapping

In the early 1990s, the Ohio State University Center for Mapping, a NASA Center for the Commercial Development of Space (CCDS), developed a system for mobile mapping called the GPSVan. While driving, the users can map an area from the sophisticated mapping van equipped with satellite signal receivers, video cameras and computer systems for collecting and storing mapping data. George J. Igel and Company and the Ohio State University Center for Mapping advanced the technology for use in determining the contours of a construction site. The new system reduces the time required for mapping and staking, and can monitor the amount of soil moved.

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Cutting More than Metal: Breaking Through the Development Cycle

NASA is advancing a new development approach and new technologies in the design construction, and testing of the next great launch vehicle for space exploration. The ability to use these new tools is made possible by a learning culture able to embrace innovation, flexibility, and prudent risk tolerance, while retaining the hard-won lessons learned through the successes and failures of the past. This paper provides an overview of the Marshall Space Flight Center's new approach to launch vehicle development, as well as examples of how that approach has been leveraged by NASA's Space Launch System (SLS) Program to achieve its key goals to safety, affordability, and sustainability.

Singer, Christopher E.↗

Colombia Mi Pronostico Flood Application: Updating and Improving the Mi Pronostico Flood Web Application to Include an Assessment of Flood Risk

Colombia is a country with highly variable terrain, from the Andes Mountains to plains and coastal areas, many of these areas are prone to flooding disasters. To identify these risk areas NASA's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) was used to construct a digital elevation model (DEM) for the study region. The preliminary risk assessment was applied to a pilot study area, the La Mosca River basin. Precipitation data from the National Aeronautics and Space Administration (NASA) Tropical Rainfall Measuring Mission (TRMM)'s near-real-time rainfall products as well as precipitation data from the Instituto de Hidrologia, Meteorologia y Estudios Ambientales (the Institute of Hydrology, Meteorology and Environmental Studies, IDEAM) and stations in the La Mosca River Basin were used to create rainfall distribution maps for the region. Using the precipitation data and the ASTER DEM, the web application, Mi Pronóstico, run by IDEAM, was updated to include an interactive map which currently allows users to search for a location and view the vulnerability and current weather and flooding conditions. The geospatial information was linked to an early warning system in Mi Pronóstico that can alert the public of flood warnings and identify locations of nearby shelters.

Rushley, Stephanie↗

Development of hypersonic engine seals - Flow effects of preload and engine pressures

A new type of engine seal is being developed to meet the needs of advanced hypersonic engines. A seal braided of emerging high temperature ceramic fibers comprised of a sheath-core construction has been selected for study based on its low leakage rates. Flexible, low-leakage, high-temperature seals are required to seal the movable engine panels of advanced ramjet-scramjet engines either preventing potentially dangerous leakage into backside engine cavities or limiting the purge coolant flow rates through the seals. To predict the leakage through these flexible, porous seal structures as a function of preload and engine pressures, new analytical flow models are required. An empirical leakage resistance/preload model is proposed to characterize the observed decrease in leakage with increasing preload. Empirically determined compression modulus and preload factor are used to correlate experimental leakage data for a wide range of seal architectures. Good agreement between measured and predicted values are observed over a range of engine pressures and seal preload.

Cai, Zhong↗

Satellite Power Systems (SPS) Space Transportation Workshop Summary

Space transportation requirements are major elements in the technical and economic realization of the entire SPS concept. First, steps in enhancing the shuttle include the Titan based liquid boost module (LBM) and liquid propellant boosters (LPB) to replace the present solid rocket boosters (SRB). The next choice between new ballistic or winged boosters must still be made; as well as the choice between series (staged) and parallel operation. Entirely new vehicles of large size are required before the economic and environmental problems of the prototype, or even demonstration, SPS can be resolved. Social impacts such as noise, and atmospheric pollution, locally and in the ionosphere, must be fully addressed. Although rather advanced technology and well developed operational management is required to properly target the average cost of gross cargo payloads into LEO at 30 $ (1979)/kg for the construction of the initial SPS, the further goal for repetitive construction of 30 to 60 SPS at 15 $ (1979)/kg for all operational payloads require the use of very advanced, long lived vehicles with a sophisticated operational organization using off shore, equatorial launch sites.

Layton, J. P.↗

Survey of needs and capabilities for wind tunnel testing of dynamic stability of aircraft at high angles of attack

A survey was conducted relative to future requirements for dynamic stability information for such aerospace vehicles as the space shuttle and advanced high performance military aircraft. High-angle-of-attack and high-Reynolds number conditions were emphasized. A review was made of the wind-tunnel capabilities in North America for measuring dynamic stability derivatives, revealing an almost total lack of capabilities that could satisfy these requirements. Recommendations are made regarding equipment that should be constructed to remedy this situation. A description is given of some of the more advanced existing capabilities, which can be used to at least partly satisfy immediate demands.

Orlik-Ruckemann, K. J.↗

Recent advances in birefringent filters

In the past several years, important developments have been made in the construction and theory of birefringent filters. Tunable filters that operate from 4500 to 7000 A with full widths at half maximum of 0.05 A and maximum transmissions of almost 20 percent have been constructed. Inexpensive large-aperture (at least 15 cm) achromatic waveplates have been fabricated which allow full use of resolution-solid angle products that are 100 times that of Fabry-Perots and 10,000 times that of grating systems.

Title, A. M.↗

Computer aided system engineering for space construction

This viewgraph presentation covers the following topics. Construction activities envisioned for the assembly of large platforms in space (as well as interplanetary spacecraft and bases on extraterrestrial surfaces) require computational tools that exceed the capability of conventional construction management programs. The Center for Space Construction is investigating the requirements for new computational tools and, at the same time, suggesting the expansion of graduate and undergraduate curricula to include proficiency in Computer Aided Engineering (CAE) though design courses and individual or team projects in advanced space systems design. In the center's research, special emphasis is placed on problems of constructability and of the interruptability of planned activity sequences to be carried out by crews operating under hostile environmental conditions. The departure point for the planned work is the acquisition of the MCAE I-DEAS software, developed by the Structural Dynamics Research Corporation (SDRC), and its expansion to the level of capability denoted by the acronym IDEAS**2 currently used for configuration maintenance on Space Station Freedom. In addition to improving proficiency in the use of I-DEAS and IDEAS**2, it is contemplated that new software modules will be developed to expand the architecture of IDEAS**2. Such modules will deal with those analyses that require the integration of a space platform's configuration with a breakdown of planned construction activities and with a failure modes analysis to support computer aided system engineering (CASE) applied to space construction.

Racheli, Ugo↗