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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

An advanced technology space station for the year 2025, study and concepts

A survey was made of potential space station missions that might exist in the 2020 to 2030 time period. Also, a brief study of the current state-of-the-art of the major subsystems was undertaken, and trends in technologies that could impact the subsystems were reviewed. The results of the survey and study were then used to arrive at a conceptual design of a space station for the year 2025. Factors addressed in the conceptual design included requirements for artificial gravity, synergies between subsystems, and the use of robotics. Suggestions are made relative to more in-depth studies concerning the conceptual design and alternative configurations.

Queijo, M. J.↗
NASA NTRS1984

Development of laminar flow control wing surface composite structures

The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program beginning in 1976 to develop technologies to improve fuel efficiency. This report documents the Lockheed-Georgia Company accomplishments under NAS1-16235 LFC Laminar-Flow-Control Wing Panel Structural Design And Development (WSSD); Design, manufacturing, and testing activities. An in-depth preliminary design of the baseline 1993 LFC wing was accomplished. A surface panel using the Lockheed graphite/epoxy integrated LFC wing box structural concept was designed. The concept was shown by analysis to be structurally efficient and cost effective. Critical details of the surface and surface joints were demonstrated by fabricating and testing complex, concept selection specimens. Cost of the baseline LFC aircraft was estimated and compared to the turbulent aircraft. The mission fuel weight was 21.7 percent lower for the LFC aircraft. The calculation shows that the lower fuel costs for LFC offset the higher incremental costs of LFC in less than six months.

Lineberger, L. B.↗
NASA NTRS1987

Frequency-response identification of XV-15 tilt-rotor aircraft dynamics

The timely design and development of the next generation of tilt-rotor aircraft (JVX) depend heavily on the in-depth understanding of existing XV-15 dynamics and the availability of fully validated simulation models. Previous studies have considered aircraft and simulation trim characteristics, but analyses of basic flight vehicle dynamics were limited to qualitative pilot evaluation. The present study has the following objectives: documentation and evaluation of XV-15 bare-airframe dynamics; comparison of aircraft and simulation responses; and development of a validated transfer-function description of the XV-15 needed for future studies. A nonparametric frequency-response approach is used which does not depend on assumed model order or structure. Transfer-function representations are subsequently derived which fit the frequency responses in the bandwidth of greatest concern for piloted handling-qualities and control-system applications.

Tischler, Mark B.↗
NASA NTRS1985

Four applications of a software data collection and analysis methodology

The evaluation of software technologies suffers because of the lack of quantitative assessment of their effect on software development and modification. A seven-step data collection and analysis methodology couples software technology evaluation with software measurement. Four in-depth applications of the methodology are presented. The four studies represent each of the general categories of analyses on the software product and development process: blocked subject-project studies, replicated project studies, multi-project variation studies, and single project strategies. The four applications are in the areas of, respectively, software testing, cleanroom software development, characteristic software metric sets, and software error analysis.

Basili, Victor R.↗
NASA NTRS1985

The SIFT hardware/software systems. Volume 1: A detailed description

This report contains a detailed description of the software implemented fault-tolerant computer's operating system and hardware subsystems. The Software Implemented Fault-Tolerant (SIFT) computer system was developed as an experimental vehicle for fault-tolerant systems research. The SIFT effort began with broad, in-depth studies stating the reliability and processing requirements for digital computers which would, in the aircraft of the 1990's, control flight-critical functions.

Palumbo, Daniel L.↗
NASA NTRS1986

A statistical trend analysis of ozonesonde data

A detailed statistical analysis of monthly averages of ozonesond readings is performed to assess trends in ozone in the troposphere and the lower to midstratosphere. Regression time series models, which include seasonal and trend factors, are estimated for 13 stations located mainly in the midlatitudes of the Northern Hemisphere. At each station, trend estimates are calculated for 14 'fractional' Umkehr layers covering the altitude range from 0 to 33 km. For the 1970-1982 period, the main findings indicate an overall negative trend in ozonesonde data in the lower stratosphere (15-21 km) of about -0.5 percent per year, and some evidence of a positive trend in the troposphere (0-5 km) of about 0.8 percent per year. An in-depth sensitivity study of the trend estimates is performed with respect to various correction procedures used to normalize ozonesonde readings to Dobson total ozone measurements. The main results indicate that the negative trend findings in the 15- to 21-km altitude region are robust to the normalization procedures considered.

Tiao, G. C.↗
NASA NTRS1987

Significance of the South Pacific Convergence Zone (SPCZ) in the energy budget of the Southern Hemisphere tropics

An in-depth investigation of the energetics, including boundary transports, was conducted on four equal-area regions in the tropical Southern Hemisphere during the SOP-1 period in 1979. The regions, each approximately centered on one of the wave axes of maximum warm rising air, include the SPCZ (115 deg W - 155 deg E) and the Australian (155-65 deg E), the African (65 deg E - 25 deg W), and the South American (25-115 deg W) regions. Daily variations of the energy conversions were examined, and time-averaged result of energy contents, conversions, and boundary transports were compiled for January 10-27. Results show that the eddy kinetic energy (KE) exceeds the eddy available potential energy (AE) in all four regions, with the largest excess being in the SPCZ. Of the conversion and flux terms, only the conversion of AE to KE is significant (again, with the greatest value in the SPCZ). An evaluation of boundary fluxes of KE indicates that the only significant transport between regions is a flow of KE from the SPCZ region into the South American region.

Hurrell, James W.↗
NASA NTRS1987

Space Construction

The purpose was to present to the aerospace community an in-depth review of Experimental Assembly of Structures on EVA (EASE)/Assembly Concept for Construction of Erectable Space Structures (ACCESS) space flight experiments and to present the status of activities regarding future space flight experiments and accompanying technology developments that will demonstrate the capability of on-orbit construction required for the Space Station.

Hagaman, Jane A.↗
NASA NTRS1984

Structural tests and development of a laminar flow control wing surface composite chordwise joint

The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program beginning in 1976 to develop technologies to improve fuel efficiency. The Lockheed-Georgia Company accomplished under NAS1-16235 Laminar-Flow-Control (LFC) Wing Panel Structural Design and Development (WSSD); design, manufacturing, and testing activities. An in-depth preliminary design of the baseline 1993 LFC wing was accomplished. A surface panel using the Lockheed graphite/epoxy integrated LFC wing box structural concept was designed. The concept was shown by analysis to be structurally efficient and cost effective. Critical details of the surface and surface joint was demonstrated by fabricating and testing complex, concept selection specimens. The Lockheed-Georgia Company accomplishments, Development of LFC Wind Surface Composite Structures (WSCS), are documented. Tests were conducted on two CV2 panels to verify the static tension and fatigue strength of LFC wing surface chordwise joints.

Lineberger, L. B.↗
NASA NTRS1988

Helicopter crashworthiness research program

Results are presented from the U.S. Army-Aerostructures Directorate/NASA-Langley Research Center joint research program on helicopter crashworthiness. Through the on-going research program an in-depth understanding was developed on the cause/effect relationships between material and architectural variables and the energy-absorption capability of composite material and structure. Composite materials were found to be efficient energy absorbers. Graphite/epoxy subfloor structures were more efficient energy absorbers than comparable structures fabricated from Kevlar or aluminum. An accurate method predicting the energy-absorption capability of beams was developed.

Farley, Gary L.↗
NASA NTRS1987

The IDEAL (Integrated Design and Engineering Analysis Languages) modeling methodology: Capabilities and Applications

The IDEAL (Integrated Design and Engineering Analysis Languages) modeling methodology has been formulated and applied over a five-year period. It has proven to be a unique, integrated approach utilizing a top-down, structured technique to define and document the system of interest; a knowledge engineering technique to collect and organize system descriptive information; a rapid prototyping technique to perform preliminary system performance analysis; and a sophisticated simulation technique to perform in-depth system performance analysis.

Evers, Ken H.↗
NASA NTRS1987

Development of a facility using robotics for testing automation of inertial instruments

The Integrated Robotics System Simulation (ROBSIM) was used to evaluate the performance of the PUMA 560 arm as applied to testing of inertial sensors. Results of this effort were used in the design and development of a feasibility test environment using a PUMA 560 arm. The implemented facility demonstrated the ability to perform conventional static inertial instrument tests (rotation and tumble). The facility included an efficient data acquisitions capability along with a precision test servomechanism function resulting in various data presentations which are included in the paper. Analysis of inertial instrument testing accuracy, repeatability and noise characteristics are provided for the PUMA 560 as well as for other possible commercial arm configurations. Another integral aspect of the effort was an in-depth economic analysis and comparison of robot arm testing versus use of contemporary precision test equipment.

Greig, Joy Y.↗
NASA NTRS1987

Animal research on the Space Station

The need for in-depth, long- and short-term animal experimentation in space to qualify man for long-duration space missions, and to study the effects of the absence and presence of Earth's gravity and of heavy particle radiation on the development and functioning of vertebrates is described. The major facilities required for these investigations and to be installed on the Space Station are: modular habitats for holding rodents and small primates in full bioisolation; a habitat holding facility; 1.8 and 4.0 m dia centrifuges; a multipurpose workbench; and a cage cleaner/disposal system. The design concepts, functions, and characteristics of these facilities are described.

Bonting, S. L.↗
NASA NTRS1986

Martian geomorphology and its relation to subsurface volatiles

Martian volatile inventory, planetary climatic and atmospheric evolution, and the interpretation of various remote sensing data were discussed. A number of morphologies that were cited as potential indicators of subsurface volatiles were reviewed. Rampart craters and terrain softening were the focus of more in-depth discussion because of the popular attention they have received and the fact that their areal distributions are by far the most extensive of all the proposed indicators.

Clifford, Stephen M.↗
NASA NTRS1988

Research Study: Space Shuttle Main Engine Plume Flowfield Model

The initial research effort was an in-depth analysis of the shuttle main engine plumes in an effort to improve the flowfield model and to enhance shuttle base heating equipment predictions during ascent. A prediction methodology code was developed incorporating the improved plume model into a predictive tool which could consider different trajectoreis and engine perfromance variables. Various plume flow model improvement studies were ongoing at the time of the 51-L accident. Since that time, base heating and plume methodology improvements have continued as part of the overall emphasis on Shuttle design assurance before resuming flight schedule.

Bender, Robert L.↗
NASA NTRS1988

Cardiovascular effects of weightlessness and ground-based simulation

A large number of animal and human flight and ground-based studies were conducted to uncover the cardiovascular effects of weightlessness. Findings indicate changes in cardiovascular function during simulations and with spaceflight that lead to compromised function on reambulation and/or return to earth. This altered state termed cardiovascular deconditioning is most clearly manifest when in an erect body state. Hemodynamic parameters inidicate the presence of excessive tachnycardia, hypotension (leading to presyncope in one-third of the subjects), decreased heart volume, decreased plasma and circulating blood volumes and loss of skeletal muscle mass, particularly in the lower limbs. No clinically harmful effects were observed to date, but in-depth follow-ups were limited, as was available physiologic information. Available data concerning the causes for the observed changes indicate significant roles for mechanisms involved with body fluid-volume regulation, altered cardiac function, and the neurohumoral control of the control of the peripheral circulation. Satisfactory measures are not found. Return to preflight state was variable and only slightly dependent on flight duration. Future progress awaits availability of flight durations longer than several weeks.

Sandler, Harold↗
NASA NTRS1988

The Environment for Application Software Integration and Execution (EASIE), version 1.0. Volume 3: Program execution guide

The Environment for Application Software Integration and Execution, EASIE, provides a methodology and a set of software utility programs to ease the task of coordinating engineering design and analysis codes. EASIE was designed to meet the needs of conceptual design engineers that face the task of integrating the results of many stand-alone engineering analysis programs. EASIE provides access to these programs via a quick, uniform, user-friendly interface. In addition, EASIE provides utilities which aid in the execution of the following tasks: selection of application programs, modification and review of program data, automatic definition and coordination of data files during program execution and a logging of steps executed throughout a design study. Volume 3, the Program Execution Guide, describes the executive capabilities provided by EASIE and defines the command language and menus available under Version 1.0. EASIE provides users with two basic modes of operation. One is the Application-Derived Executive (ADE) which provides users with sufficient guidance to quickly review data, select menu action items, and execute application programs. The second is the Complete Control Executive (CCE), which provides a full executive interface allowing users in-depth control of the design process.

Schwing, James L.↗
NASA NTRS1988

Proceedings of the Mobile Satellite Conference

A satellite-based mobile communications system provides voice and data communications to mobile users over a vast geographic area. The technical and service characteristics of mobile satellite systems (MSSs) are presented and form an in-depth view of the current MSS status at the system and subsystem levels. Major emphasis is placed on developments, current and future, in the following critical MSS technology areas: vehicle antennas, networking, modulation and coding, speech compression, channel characterization, space segment technology and MSS experiments. Also, the mobile satellite communications needs of government agencies are addressed, as is the MSS potential to fulfill them.

Rafferty, William↗