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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 1,423 records · Page 79
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Utilization of Shuttle small payload accommodations in the DOD Space Test Program

Over the past 27 years, the U.S. Air Force, as executive agent for the Department of Defense (DOD) Space Test Program, has flown approximately 325 space experiments for the Army, Navy, Air Force, and other DOD agencies. These experiments have made significant contributions to the improvement of military technology and operations. Flight of Space Test Program experiments has been carried out utilizing free flyer spacecraft, the Space Shuttle crew cabin, and the Space Shuttle cargo bay. This paper will concentrate on those experiments which have been flown by the NASA Space Shuttle small payload flight systems, e.g., GAS, uprated GAS (CAP), and Hitchhiker flight systems. Discussions of Space Test Program experiments flown by Space Shuttle small payloads flight systems will include the experiment objectives, the accommodations and services provided by the flight systems, experiment results, and lessons learned from the planning and conduct of the flight. Particular emphasis will be placed on those experiments which required and were provided with a new and unique capability by the small payloads flight systems. These capabilities include the first use of the GAS opening lid, the first use of the GAS payload ejection capability, and the first use of the Hitchhiker cross bay carrier.

Hagler, Thomas↗
NASA NTRS1993

Technology utilization office data base analysis and design

NASA Headquarters is placing a high priority on the transfer of NASA and NASA contractor developed technologies and expertise to the private sector and to other federal, state and local government organizations. The ultimate objective of these efforts is positive economic impact, an improved quality of life, and a more competitive U.S. posture in international markets. The Technology Utilization Office (TUO) currently serves seven states with its technology transfer efforts. Since 1989, the TUO has handled over one-thousand formal requests for NASA related technologies assistance. The technology transfer process requires promoting public awareness of NASA related soliciting requests for assistance, matching technologies to specific needs, assuring appropriate technology transfer, and monitoring and evaluating the process. Each of these activities have one very important aspect in common: the success of each is dissemination of appropriate high quality information. The purpose of the research was to establish the requirements and develop a preliminary design for a database system to increase the effectiveness and efficiency of the TUO's technology transfer function. The research was conducted following the traditional systems development life cycle methodology and was supported through the use of modern structured analysis techniques. The next section will describe the research and findings as conducted under the life cycle approach.

Floyd, Stephen A.↗
NASA NTRS1992

Asteroid exploration and utilization

The Earth is nearing depletion of its natural resources at a time when human beings are rapidly expanding the frontiers of space. The resources possessed by asteroids have enormous potential for aiding and enhancing human space exploration as well as life on Earth. Project STONER (Systematic Transfer of Near Earth Resources) is based on mining an asteroid and transporting raw materials back to Earth. The asteroid explorer/sample return mission is designed in the context of both scenarios and is the first phase of a long range plan for humans to utilize asteroid resources. Project STONER is divided into two parts: asteroid selection and explorer spacecraft design. The spacecraft design team is responsible for the selection and integration of the subsystems: GNC, communications, automation, propulsion, power, structures, thermal systems, scientific instruments, and mechanisms used on the surface to retrieve and store asteroid regolith. The sample return mission scenario consists of eight primary phases that are critical to the mission.

Radovich, Brian M.↗
NASA NTRS1994

An analysis of carrier phase jitter in an MPSK receiver utilizing map estimation

The use of 8 and 16 PSK TCM to support satellite communications in an effort to achieve more bandwidth efficiency in a power-limited channel has been proposed. This project addresses the problem of carrier phase jitter in an M-PSK receiver utilizing the high SNR approximation to the maximum aposteriori estimation of carrier phase. In particular, numerical solutions to the 8 and 16 PSK self-noise and phase detector gain in the carrier tracking loop are presented. The effect of changing SNR on the loop noise bandwidth is also discussed. These data are then used to compute variance of phase error as a function of SNR. Simulation and hardware data are used to verify these calculations. The results show that there is a threshold in the variance of phase error versus SNR curves that is a strong function of SNR and a weak function of loop bandwidth. The M-PSK variance thresholds occur at SNR's in the range of practical interest for the use of 8 and 16-PSK TCM. This suggests that phase error variance is an important consideration in the design of these systems.

Osborne, William P.↗
NASA NTRS1994

Electrical characterization of a Space Station Freedom alpha utility transfer assembly

Electrical power, command signals and data are transferred across the Space Station Freedom solar alpha rotary joint by roll rings, which are incorporated within the Utility Transfer Assembly (UTA) designed and manufactured by Honeywell Space Systems Operations. A developmental Model of the UTA was tested at the NASA Lewis Research Center using the Power Management and Distribution DC test bed. The objectives of these tests were to obtain data for calibrating system models and to support final design of qualification and flight units. This testing marked the first time the UTA was operated at high power levels and exposed to electrical conditions similar to that which it will encounter on the actual Space Station. Satisfactory UTA system performance was demonstrated within the scope of this testing.

Yenni, Edward J.↗
NASA NTRS1994

National Maglev initiative: California line electric utility power system requirements

The electrical utility power system requirements were determined for a Maglev line from San Diego to San Francisco and Sacramento with a maximum capacity of 12,000 passengers an hour in each direction at a speed of 300 miles per hour, or one train every 30 seconds in each direction. Basically the Maglev line requires one 50-MVA substation every 12.5 miles. The need for new power lines to serve these substations and their voltage levels are based not only on equipment loading criteria but also on limitations due to voltage flicker and harmonics created by the Maglev system. The resulting power system requirements and their costs depend mostly on the geographical area, urban or suburban with 'strong' power systems, or mountains and rural areas with 'weak' power systems. A reliability evaluation indicated that emergency power sources, such as a 10-MW battery at each substation, were not justified if sufficient redundancy is provided in the design of the substations and the power lines serving them. With a cost of $5.6 M per mile, the power system requirements, including the 12-kV DC cables and the inverters along the Maglev line, were found to be the second largest cost component of the Maglev system, after the cost of the guideway system ($9.1 M per mile), out of a total cost of $23 M per mile.

Save, Phil↗
NASA NTRS1994

A coupled/uncoupled deformation and fatigue damage algorithm utilizing the finite element method

A fatigue damage computational algorithm utilizing a multiaxial, isothermal, continuum based fatigue damage model for unidirectional metal matrix composites has been implemented into the commercial finite element code MARC using MARC user subroutines. Damage is introduced into the finite element solution through the concept of effective stress which fully couples the fatigue damage calculations with the finite element deformation solution. An axisymmetric stress analysis was performed on a circumferentially reinforced ring, wherein both the matrix cladding and the composite core were assumed to behave elastic-perfectly plastic. The composite core behavior was represented using Hill's anisotropic continuum based plasticity model, and similarly, the matrix cladding was represented by an isotropic plasticity model. Results are presented in the form of S-N curves and damage distribution plots.

Wilt, Thomas E.↗
NASA NTRS1993

Project Hyreus: Mars sample return mission utilizing in situ propellant production

Project Hyreus is an unmanned Mars sample return mission that utilizes propellants manufactured in situ from the Martian atmosphere for the return voyage. A key goal of the mission is to demonstrate the considerable benefits of using indigenous resources and to test the viability of this approach as a precursor to manned Mars missions. The techniques, materials, and equipment used in Project Hyreus represent those that are currently available or that could be developed and readied in time for the proposed launch date in 2003. Project Hyreus includes such features as a Mars-orbiting satellite equipped with ground-penetrating radar, a large rover capable of sample gathering and detailed surface investigations, and a planetary science array to perform on-site research before samples are returned to Earth. Project Hyreus calls for the Mars Landing Vehicle to land in the Mangala Valles region of Mars, where it will remain for approximately 1.5 years. Methane and oxygen propellant for the Earth return voyage will be produced using carbon dioxide from the Martian atmosphere and a small supply of hydrogen brought from Earth. This process is key to returning a large Martian sample to Earth with a single Earth launch.

Abrego, Anita↗
NASA NTRS1994

Navy and the HARV: High angle of attack tactical utility issues

This presentation will highlight results from the latest Navy evaluation of the HARV (March 1994) and focus primarily on the impressions from a piloting standpoint of the tactical utility of thrust vectoring. Issue to be addressed will be mission suitability of high AOA flight, visual and motion feedback cues associated with operating at high AOA, and the adaptability of a pilot to effectively use the increased control power provided by the thrust vectoring system.

Sternberg, Charles A.↗
NASA NTRS1994

An unmanned mission to Mars with sample collection and in-situ resource utilization

The design for the Mars Analysis and Return Vehicle with In-Situ Resource Utilization (MARVIN) project is outlined. The MARVIN mission is designed to collect samples of the Martian environment; to produce fuel from local Martian resources; and to use the fuel produced to return the samples to earth. It uses only existing technologies. Exploratory Technologies' mission-design efforts have focused on methods of orbit determination, sample collection, fuel production, power, communications, control, and structural design. Lambert Targeting provided Delta-V's, launch dates, and travel times. The landing site is the Tharsis Plateau, to the southeast of Olympus Mons, chosen for its substantial scientific value. Samples of soil, dust, and atmosphere are collected with lander-based collection devices: the soil sample, with a robotic arm similar to those used in the Viking missions; the atmospheric sample, from a bleed line to the compressor in the fuel-production facility; a dust sample, from the dust-collection container in the fuel-production facility; and a redundant dust sample, with a with a passive filter system, which relies upon neither a power source nor other collection methods. The sample-return capsule (SRC) houses these samples, which are triply contained to prevent contamination. Proven technology can be used to produce methane and oxygen for fuel with relative ease at the landing site: the Sabatier reactor produces methane and water by combining carbon dioxide and hydrogen (brought from earth); the Reverse Water-Gas Shift unit combines carbon dioxide and hydrogen to form carbon monoxide and water; a water-electrolysis unit splits the water into hydrogen and oxygen. The Mars-lander vehicle (MLV) transports the equipment from earth to Mars. The Mars-ascent vehicle (MAV) contains the SRC and the engine, which is the same for both the MLV and the MAV. All equipment that is unnecessary for the Mars-Earth trajectory remains on Mars. This report presents detailed sizing information, for which a spreadsheet has been developed. The trends suggest possibilities for expansion, and suggestions for future work in these areas are offered.

Source record↗
NASA NTRS1994

Study of development and utilization of a multipurpose atmospheric corrosion sensor

There has been a critical need for analyzing various aspects of atmospheric corrosion and for the development of atmospheric corrosion microsensors. The project work has involved the following activities: (1) making of multielectrode corrosion monitors on dielectric substrates; (2) testing them in the laboratory for functional characteristics; (3) preparing a report on the state of the art of atmospheric corrosion sensor development around the world; and (4) corrosion testing of electrochemical changes of sensor specimens and related fog testing. The study included work on the subject of development and utilization of a multipurpose atmospheric corrosion sensor and this report is the annual report on work carried out on this research project. This has included studies on the development of sensors of two designs, stage 1 and stage 2, and with glass and alumina substrate, experimentation and development and characterization of the coating uniformity, aspects of corrosion monitoring, literature search on the corrosion sensors and their development. A state of the art report on atmospheric corrosion sensor development was prepared and submitted.

Diwan, Ravinder M.↗
NASA NTRS1995

Leak detection utilizing analog binaural (VLSI) techniques

A detection method and system utilizing silicon models of the traveling wave structure of the human cochlea to spatially and temporally locate a specific sound source in the presence of high noise pandemonium. The detection system combines two-dimensional stereausis representations, which are output by at least three VLSI binaural hearing chips, to generate a three-dimensional stereausis representation including both binaural and spectral information which is then used to locate the sound source.

Hartley, Frank T.↗
NASA NTRS1995

On the utility of threads for data parallel programming

Threads provide a useful programming model for asynchronous behavior because of their ability to encapsulate units of work that can then be scheduled for execution at runtime, based on the dynamic state of a system. Recently, the threaded model has been applied to the domain of data parallel scientific codes, and initial reports indicate that the threaded model can produce performance gains over non-threaded approaches, primarily through the use of overlapping useful computation with communication latency. However, overlapping computation with communication is possible without the benefit of threads if the communication system supports asynchronous primitives, and this comparison has not been made in previous papers. This paper provides a critical look at the utility of lightweight threads as applied to data parallel scientific programming.

Fahringer, Thomas↗
NASA NTRS1992

Martian resource utilization. 1: Plant design and transportation selection criteria

Indigenous Space Materials Utilization (ISMU) provides an opportunity to make Mars exploration mission scenarios more affordable by reducing the initial mass necessary in Low Earth Orbit (LEO). Martian propellant production is discussed in terms of simple design and economic tradeoffs. Fuel and oxidizer combinations included are H2/O2, CH4/O2, and CO/O2. Process flow diagrams with power and mass flow requirements are presented for a variety of processes, and some design requirements are derived. Maximum allowable plant masses for single use amortization are included.

Kaloupis, Peter↗
NASA NTRS1993

Utilization of on-site resources for regenerative life support systems at Lunar and Martian outposts

Lunar and martian materials can be processed and used at planetary outposts to reduce the need (and thus the cost) of transportng supplies from Earth. A variety of uses for indigenous, on-site materials have been suggested, including uses as rocket propellants, construction materials, and life support materials. Utilization of on-site resources will supplement Regenerative Life Support Systems (RLSS) that will be needed to regenerate air, water, wastes, and to produce food (e.g., plants) for human consumption during long-duration space missions. Natural materials on the Moon and/or Mars may be used for a variety of RLSS needs including (1) soils or solid-support substrate for plant growth, (2) sources for extraction of essential plant-growth nutrients, (3) sources of O2, H2, CO2, and water, (4) substrates for microbial populations in the degradation of wastes, and (5) shielding materials surrounding outpost structures to protect humans, plants, and microorganisms from radiation. In addition to the regolith, the martian atmosphere will provide additional resources at a Mars outpost, including water, CO2 and other atmospheric gases.

Ming, Douglas W.↗
NASA NTRS1993

Flight performance measurement utilizing a figure of merit (FOM)

One of the goals of the NASA Strategic Behavior/Workload Management Program is to develop standardized procedures for constructing figures of merit (FOMs) that describe minimal criteria for flight task performance, as well as summarize overall performance quality. Such a measure could be utilized for evaluating flight crew performance, for assessing the effectiveness of new equipment or technological innovations, or for measuring performance at a particular airport. In this report, we describe the initial phases in the creation of a FOM to be employed in examining crew performance in NASA-Ames Air Ground Compatibility and Strategic Behavior/Workload Management programs.

Mosier, Kathleen L.↗
NASA NTRS1995

A study of blade-vortex interaction aeroacoustics utilizing an independently generated vortex

This paper presents results from an experimental study of rotor blade-vortex interaction (BVI) aerodynamics and acoustics. The experiment utilized an externally generated vortex interacting with a two-bladed rotor operating at zero thrust to minimize the influence of the rotor's own wake. The rotor blades were instrumented with a total of 60 absolute pressure transducers at three spanwise and ten chordwise stations on both the upper and lower surfaces. Acoustic data were obtained with fixed near-field microphones as well as a movable array of far-field microphones. The test was carried out in the acoustically treated test section of the NASA Ames 80- by 120-foot Wind Tunnel. Several parameters which influences BVI, such as vortex-rotor separation distance, vortex strength, and vortex sense (swirl direction), as well as rotor tip Mach number and advance ratio, were varied. Simultaneous measurements were obtained of blade surface pressure distributions, near-field acoustics, and far-field acoustics during the vortex-blade encounters.

Kitaplioglu, C.↗