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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 865 records · Page 48

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NASA NTRS1977

Methodology for back-contamination risk assessment for a Mars sample return mission

The risk of back-contamination from Mars Surface Sample Return (MSSR) missions is assessed. The methodology is designed to provide an assessment of the probability that a given mission design and strategy will result in accidental release of Martian organisms acquired as a result of MSSR. This is accomplished through the construction of risk models describing the mission risk elements and their impact on back-contamination probability. A conceptual framework is presented for using the risk model to evaluate mission design decisions that require a trade-off between science and planetary protection considerations.

Merkhofer, M. W.↗

NASA NTRS1979

Analysis of building heating and cooling

Energy Conservation Program (ECP) gives design engineer methodology and easy-to-use computer program for simulating hourly thermal characteristics over full year for individually characterized zones within building. Inexpensive system can be used to develop thermal model of building to aid selection of most suitable and economical heating and cooling system for building

Chai, V. W.↗

NASA NTRS1978

The aerodynamic design of an advanced rotor airfoil

An advanced rotor airfoil, designed utilizing supercritical airfoil technology and advanced design and analysis methodology is described. The airfoil was designed subject to stringent aerodynamic design criteria for improving the performance over the entire rotor operating regime. The design criteria are discussed. The design was accomplished using a physical plane, viscous, transonic inverse design procedure, and a constrained function minimization technique for optimizing the airfoil leading edge shape. The aerodynamic performance objectives of the airfoil are discussed.

Blackwell, J. A., Jr.↗

NASA NTRS1979

Frequency dependent precompensation for dominance in a four input/output theme problem model

This paper reports on additional experience in applying the CARDIAD methodology to design of dynamical input compensation to achieve column dominance for linear multivariable models of realistic turbine engine simulations. In particular, the approach has been extended to models having four inputs and four outputs, and successful compensations have been achieved with an investment of about thirty minutes desk time.

Schafer, R. M.↗

NASA NTRS1980

Acoustoelasticity - Review and extension

Research on the interaction between the sound pressure field and the flexible wall of an enclosure is reviewed. The topics discussed include: a mathematical model, simplified solutions for sinusoidal excitation, damping, random excitation, numerical results, including comparisons with representative experimental data, and design analysis methodology. Results of various authors using finite element techniques and modal analysis suggest that effective analytical models are available.

Dowell, E. H.↗

NASA NTRS1979

NASA biomedical applications team. Applications of aerospace technology in biology and medicine

The use of a bipolar donor-recipient model of medical technology transfer is presented. That methodology is designed to: (1) identify medical problems and aerospace technology that in combination constitute opportunities for successful medical products; (2) obtain the early participation of industry in the transfer process; and (3) obtain acceptance by the medical community of new medical products based on aerospace technology. Problem descriptions and activity reports and the results of a market study on the tissue freezing device are presented.

Rouse, D. J.↗

NASA NTRS1982

A study of the selection of microcomputer architectures to automate planetary spacecraft power systems

Performance and reliability models of alternate microcomputer architectures as a methodology for optimizing system design were examined. A methodology for selecting an optimum microcomputer architecture for autonomous operation of planetary spacecraft power systems was developed. Various microcomputer system architectures are analyzed to determine their application to spacecraft power systems. It is suggested that no standardization formula or common set of guidelines exists which provides an optimum configuration for a given set of specifications.

Nauda, A.↗

NASA NTRS1978

Applications of aerospace technology in biology and medicine

A bipolar, donor-recipient model of medical technology transfer is introduced to provide a basis for the team's methodology. That methodology is designed (1) to identify medical problems and NASA technology that in combination constitute opportunities for successful medical products, (2) to obtain the early participation of industry in the transfer proces, and (3) to obtain acceptance by the medical community of new medical products based on NASA technology. Two commercial technology transfers and five institutional technology transfers were completed in 1977. A new, commercially available teaching manikin system uses NASA-developed concepts and techniques for effective visual presentation of information and data. Drugs shipped by the National Cancer Institute to locations throughout the world are maintained at low temperatures in shipping containers that incorporate recommendations made by NASA.

Beall, H. C.↗

NASA NTRS1981

Control technology as applied to Space Telescope

The pointing control system (PCS) of the Space Telescope is addressed. The sensors employed in the primary PCS mode are the rate gyro assembly and the fine guidance sensors, while four reaction wheel assemblies provide control torques. Stability considerations based on structural modes are discussed, noting the stability margin criteria used in the design. Acquisition methodology is considered with regard to the PCS component hardware simulators and vehicle dynamics simulation.

Dougherty, H.↗

NASA NTRS1985

Software Design Analyzer System

CRISP80 software design analyzer system a set of programs that supports top-down, hierarchic, modular structured design, and programing methodologies. CRISP80 allows for expression of design as picture of program.

Tausworthe, R. C.↗

NASA NTRS1983

Cleanroom certification model

The Cleanroom software development methodology is designed to take the gamble out of product releases for both suppliers and receivers of the software. The ingredients of this procedure are a life cycle of executable product increments, representative statistical testing, and a standard estimate of the MTTF (Mean Time To Failure) of the product at the time of its release. A statistical approach to software product testing using randomly selected samples of test cases is considered. A statistical model is defined for the certification process which uses the timing data recorded during test. A reasonableness argument for this model is provided that uses previously published data on software product execution. Also included is a derivation of the certification model estimators and a comparison of the proposed least squares technique with the more commonly used maximum likelihood estimators.

Currit, P. A.↗

NASA NTRS1982

Applications of aerospace technology in biology and medicine

Utilization of National Aeronautics and Space Administration (NASA) technology in medicine is discussed. The objective is best obtained by stimulation of the introduction of new or improved commercially available medical products incorporating aerospace technology. A bipolar donor/recipient model of medical technology transfer is presented to provide a basis for the team's methodology. That methodology is designed to: (1) identify medical problems and NASA technology that, in combination, constitute opportunities for successful medical products; (2) obtain the early participation of industry in the transfer process; and (3) obtain acceptance by the medical community of new medical products based on NASA technology. Two commercial transfers were completed: the Stowaway, a lightweight wheelchair that provides mobility for the disabled and elderly in the cabin of commercial aircraft, and Micromed, a portable medication infusion pump for the reliable, continuous infusion of medications such as heparin or insulin. The marketing and manufacturing factors critical to the commercialization of the lightweight walker incorporating composite materials were studied. Progress was made in the development and commercialization of each of the 18 currently active projects.

Bass, B.↗

NASA NTRS1983

Applications of aerospace technology in biology and medicine

Utilization of NASA technology and its application to medicine is discussed. The introduction of new or improved commercially available medical products and incorporation of aerospace technology is outlined. A biopolar donor-recipient model of medical technology transfer is presented to provide a basis for the methodology. The methodology is designed to: (1) identify medical problems and NASA technology that, in combination, constitute opportunities for successful medical products; (2) obtain the early participation of industry in the transfer process; and (3) obtain acceptance by the medical community of new medical products based on NASA technology. Two commercial transfers were completed: the ocular screening device, a system for quick detection of vision problems in preschool children, and Porta-Fib III, a hospital monitoring unit. Two institutional transfers were completed: implant materials testing, the application of NASA fracture control technology to improve reliability of metallic prostheses, and incinerator monitoring, a quadrupole mass spectrometer to monitor combustion products of municipal incinerators. Mobility aids for the blind and ultrasound diagnosis of burn depth are also studied.

Rouse, D. J.↗

NASA NTRS1984

Applications of aerospace technology

The objective of the Research Triangle Institute Technology Transfer Team is to assist NASA in achieving widespread utilization of aerospace technology in terrestrial applications. Widespread utilization implies that the application of NASA technology is to benefit a significant sector of the economy and population of the Nation. This objective is best attained by stimulating the introduction of new or improved commercially available devices incorporating aerospace technology. A methodology is presented for the team's activities as an active transfer agent linking NASA Field Centers, industry associations, user groups, and the medical community. This methodology is designed to: (1) identify priority technology requirements in industry and medicine, (2) identify applicable NASA technology that represents an opportunity for a successful solution and commercial product, (3) obtain the early participation of industry in the transfer process, and (4) successfully develop a new product based on NASA technology.

Rouse, Doris J.↗

NASA NTRS1987

Probabilistic structural analysis to quantify uncertainties associated with turbopump blades

A probabilistic study of turbopump blades has been in progress at NASA Lewis Research Center for over the last two years. The objectives of this study are to evaluate the effects of uncertainties in geometry and material properties on the structural response of the turbopump blades to evaluate the tolerance limits on the design. A methodology based on probabilistic approach has been developed to quantify the effects of the random uncertainties. The results of this study indicate that only the variations in geometry have significant effects.

Nagpal, Vinod K.↗

NASA NTRS1988

Probabilistic structural analysis to quantify uncertainties associated with turbopump blades

A probabilistic study of turbopump blades has been in progress at NASA Lewis Research Center for over the last two years. The objectives of this study are to evaluate the effects of uncertainties in geometry and material properties on the structural response of the turbopump blades to evaluate the tolerance limits on the design. A methodology based on probabilistic approach was developed to quantify the effects of the random uncertainties. The results indicate that only the variations in geometry have significant effects.

Nagpal, Vinod K.↗

NASA NTRS1989

Evaluation of fault-tolerant parallel-processor architectures over long space missions

The impact of a five year space mission environment on fault-tolerant parallel processor architectures is examined. The target application is a Strategic Defense Initiative (SDI) satellite requiring 256 parallel processors to provide the computation throughput. The reliability requirements are that the system still be operational after five years with .99 probability and that the probability of system failure during one-half hour of full operation be less than 10(-7). The fault tolerance features an architecture must possess to meet these reliability requirements are presented, many potential architectures are briefly evaluated, and one candidate architecture, the Charles Stark Draper Laboratory's Fault-Tolerant Parallel Processor (FTPP) is evaluated in detail. A methodology for designing a preliminary system configuration to meet the reliability and performance requirements of the mission is then presented and demonstrated by designing an FTPP configuration.

Johnson, Sally C.↗

NASA NTRS1989

DSN radio science system design and testing for Voyager-Neptune encounter

The Deep Space Network (DSN) Radio Science System presently implemented within the Deep Space Network was designed to meet stringent requirements imposed by the demands of the Voyager-Neptune encounter and future missions. One of the initial parameters related to frequency stability is discussed. The requirement, specification, design, and methodology for measuring this parameter are described. A description of special instrumentation that was developed for the test measurements and initial test data resulting from the system tests performed at Canberra, Australia and Usuda, Japan are given.

Ham, N. C.↗