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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 1,009 records · Page 56
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Crew emergency return vehicle - Electrical power system design study

A crew emergency return vehicle (CERV) is proposed to perform the lifeboat function for the manned Space Station Freedom. This escape module will be permanently docked to Freedom and, on demand, will be capable of safely returning the crew to earth. The unique requirements that the CERV imposes on its power source are presented, power source options are examined, and a baseline system is selected. It consists of an active Li-BCX DD-cell modular battery system and was chosen for the maturity of its man-rated design and its low development costs.

Darcy, E. C.↗
NASA NTRS1974

Earth Observatory Satellite system definition study. Report no. 3: Design/cost tradeoff studies. Appendix A: EOS program WBS dictionary. Appendix B: EOS mission functional analysis

The work breakdown structure (WBS) dictionary for the Earth Observatory Satellite (EOS) is defined. The various elements of the EOS program are examined to include the aggregate of hardware, computer software, services, and data required to develop, produce, test, support, and operate the space vehicle and the companion ground data management system. A functional analysis of the EOS mission is developed. The operations for three typical EOS missions, Delta, Titan, and Shuttle launched are considered. The functions were determined for the top program elements, and the mission operations, function 2.0, was expanded to level one functions. Selection of ten level one functions for further analysis to level two and three functions were based on concern for the EOS operations and associated interfaces.

Source record↗
NASA NTRS2020

Gondola For High Altitude Planetary Science (GHAPS) Guide System Trade Study

The Gondola for High-Altitude Planetary Science (GHAPS) project is a balloon-borne astronomical observatory designed operate in the ultraviolet, Visible, and near-mid infrared spectral region. The GHAPS Optical Telescope Assembly (OTA) is designed around a 1-m aperture narrow field-of-view telescope with near-diffraction-limited performance. GHAPS will utilize Wallops Arc-Second Pointing System (WASP) for pointing the OTA with an accuracy of 1 arcsec or better. WASP relies heavily on a self-contained star tracker assembly to determine the OTA line of sight. Preliminary structural analysis indicates that potential misalignments could be present between the OTA line of sight and the star tracker FOV center during the expected flight conditions that could compromise GHAPS pointing accuracy.

Telescope Image Guider↗
NASA NTRS1974

Earth Observatory Satellite system definition study. Report 2: Instrument constraints and interfaces

The instrument constraints and interface specifications for the Earth Observatory Satellite (EOS) are discussed. The Land Use Classification Mission using a 7 band Thematic Mapper and a 4 band High Resolution Pointable Imager is stressed. The mission and performance of the instruments were reviewed and expanded to reflect the instrument as a part of the total remote sensing system. A preliminary EOS interface handbook is provided to describe the mission and system, to specify the spacecraft interfaces to potential instrument contractors, and to describe the instrument interface data required by the system integration contractor.

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NASA NTRS1975

Management systems research study

The development of a Monte Carlo simulation of procurement activities at the NASA Ames Research Center is described. Data cover: simulation of the procurement cycle, construction of a performance evaluation model, examination of employee development, procedures and review of evaluation criteria for divisional and individual performance evaluation. Determination of the influences and apparent impact of contract type and structure and development of a management control system for planning and controlling manpower requirements.

Bruno, A. V.↗
NASA NTRS1977

A system definition study for the Advanced Meteorological Temperature Sounder (AMTS)

The functional requirements of Exhibit A (11) were used as the baseline for the conceptual design of a fixed grating out of plane multidetector spectrometer for the Space Shuttle application. Because the grating instrument would be large and the 28 element detector array would be difficult to cool radiatively from a free flying spacecraft and because increasing the spectral resolution of the grating instrument would be difficult in an instrument of reasonable size, a parallel study of a Nichelson interferometer spectrometer was undertaken. This type of instrument offers compact size, fewer detectors to cool, and the possibility of increased spectral resolution. The design and performance parameters of both the grating and interferometer approaches are described. The tradeoffs involved in comparing the two systems for sounding applications are discussed.

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NASA NTRS1985

Aerosol measurement program strategy for global aerosol backscatter model development

The purpose was to propose a balanced program of aerosol backscatter research leading to the development of a global model of aerosol backscatter. Such a model is needed for feasibility studies and systems simulation studies for NASA's prospective satellite-based Doppler lidar wind measurement system. Systems of this kind measure the Doppler shift in the backscatter return from small atmospheric aerosol wind tracers (of order 1 micrometer diameter). The accuracy of the derived local wind estimates and the degree of global wind coverage for such a system are limited by the local availability and by the global scale distribution of natural aerosol particles. The discussions here refer primarily to backscatter model requirements at CO2 wavelengths, which have been selected for most of the Doppler lidar systems studies to date. Model requirements for other potential wavelengths would be similar.

Bowdle, David A.↗
NASA NTRS1992

AMTEC system performance studies using the detailed electrode kinetic and transport model

A detailed electrochemical model of the alkali metal thermoelectric converter (AMTEC) electrode and current collector grid has been developed recently. Comparative evaluations of the resulting differences in model predictions reveal that the new detailed model predicts up to 50 percent higher electrode power densities at condenser operating temperatures above 600 K. The new model, with experimentally determined parameters, was used to recalculate the projected system performance of previously reported 1- and 100-kWe AMTEC space power systems that had incorporated earlier electrolyte/electrode models. It was found that when the detailed model was used to determine the electrode power densities, enhanced specific power and efficiencies are predicted.

Sievers, Robert K.↗
NASA NTRS1992

Advanced expander test bed engine

The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high pressure expander cycle concept, study system interactions, and conduct studies of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

Mitchell, J. P.↗
NASA NTRS2008

Power System Trade Studies for the Lunar Surface Access Module

A Lunar Lander Preparatory Study (LLPS) was undertaken for NASA's Lunar Lander Pre-Project in 2006 to explore a wide breadth of conceptual lunar lander designs. Civil servant teams from nearly every NASA center responded with dozens of innovative designs that addressed one or more specific lander technical challenges. Although none of the conceptual lander designs sought to solve every technical design issue, each added significantly to the technical database available to the Lunar Lander Project Office as it began operations in 2007. As part of the LLPS, a first order analysis was performed to identify candidate power systems for the ascent and descent stages of the Lunar Surface Access Module (LSAM). A power profile by mission phase was established based on LSAM subsystem power requirements. Using this power profile, battery and fuel cell systems were modeled to determine overall mass and volume. Fuel cell systems were chosen for both the descent and ascent stages due to their low mass. While fuel cells looked promising based on these initial results, several areas have been identified for further investigation in subsequent studies, including the identification and incorporation of peak power requirements into the analysis, refinement of the fuel cell models to improve fidelity and incorporate ongoing technology developments, and broadening the study to include solar power.

Kohout, Lisa, L.↗
NASA NTRS1977

Space station systems analysis study. Part 3: Documentation. Volume 4: Supporting research and technology report

A brief description of recommended supporting research and technology items resulting from the space station analysis study is provided. Descriptions include the title; the status with respect to the state of the art; the justification; the technical plan including objectives and technical approach; resource requirements categorized by manpower, specialized facilities, and funding in 1977 dollars; and also the target schedule. The goal is to provide high confidence in the solutions for the various functional system development problems, and to do so within a time period compatible with the overall evolutionary space construction base schedule.

Source record↗
NASA NTRS1974

Human decision making in future ATC systems comparative studies in distributed traffic management

Seven different human-centered alternatives for distributing traffic management responsibility between air and ground in the terminal area were simulated and evaluated at NASA-Ames Research Center in the man-machine integration branch. The alternatives differed in three divisions of decision-making responsibility ranging from completely ground-centered to completely air-centered and in the amount of information presented to the pilots via traffic situation displays (TSD). Objective, verbal and subjective measures of system performance, workloads, preferences, etc., were obtained. Based on the task and corresponding measures, the ground-centered (vectoring) alternative was the least favorable. Best overall performance was achieved and preferred with a moderate division of responsibility in which controllers issued sequence order only and pilots used a TSD with 30 sec path predictors on their own aircraft. Speculations on the use of the results in context of a ground-centralized system failure and for future ATC systems are presented.

Kreifeldt, J. G.↗
NASA NTRS1974

Coded spread spectrum digital transmission system design study

Results are presented of a comprehensive study of the performance of Viterbi-decoded convolutional codes in the presence of nonideal carrier tracking and bit synchronization. A constraint length 7, rate 1/3 convolutional code and parameters suitable for the space shuttle coded communications links are used. Mathematical models are developed and theoretical and simulation results are obtained to determine the tracking and acquisition performance of the system. Pseudorandom sequence spread spectrum techniques are also considered to minimize potential degradation caused by multipath.

Heller, J. A.↗
NASA NTRS1978

Satellite Power Systems (SPS) concept definition study. Volume 2: SPS system requirements

Collected data reflected the level of definition resulting from the evaluation of a broad spectrum of SPS (satellite power systems) concepts. As the various concepts matured, these requirements were updated to reflect the requirements identified for the projected satellite system/subsystem point design(s). The study established several candidate concepts which were presented to provide a basis for the selection of one or two approaches that would be given a more comprehensive examination. The two selected concepts were expanded and constitute the selected system point designs. The identified system/subsystem requirements was emphasized and information on the selected point design was provided.

Hanley, G.↗
NASA NTRS1974

Project plan hydrogen energy systems technology. Phase 1: Hydrogen energy systems technology study

An overview of the potential need for hydrogen as a source of energy in the future was presented in order to identify and define the technology requirements for the most promising approaches to meet that need. The following study objectives were discussed: (1) determination of the future demand for hydrogen, based on current trends and anticipated new uses, (2) identification of the critical research and technology advances required to meet this need considering, to the extent possible, raw material limitations, economics, and environmental effects, and (3) definition and recommendation of the scope and space of a National Hydrogen Energy Systems Technology Program and outline of a Program Development Plan.

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NASA NTRS1991

Sensor data validation and reconstruction. Phase 1: System architecture study

The sensor validation and data reconstruction task reviewed relevant literature and selected applicable validation and reconstruction techniques for further study; analyzed the selected techniques and emphasized those which could be used for both validation and reconstruction; analyzed Space Shuttle Main Engine (SSME) hot fire test data to determine statistical and physical relationships between various parameters; developed statistical and empirical correlations between parameters to perform validation and reconstruction tasks, using a computer aided engineering (CAE) package; and conceptually designed an expert system based knowledge fusion tool, which allows the user to relate diverse types of information when validating sensor data. The host hardware for the system is intended to be a Sun SPARCstation, but could be any RISC workstation with a UNIX operating system and a windowing/graphics system such as Motif or Dataviews. The information fusion tool is intended to be developed using the NEXPERT Object expert system shell, and the C programming language.

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NASA NTRS2023

Designing an Observing System to Study the Surface Biology and Geology (SBG) of the Earth in the 2020s

Observations of planet Earth from space are a critical resource for science and society. Satellite measurements represent very large investments and United States (US) agencies organize their effort to maximize the return on that investment. The US National Research Council conducts a survey of Earth science and applications to prioritize observations for the coming decade. The most recent survey prioritized a visible to shortwave infrared imaging spectrometer and a multispectral thermal infrared imager to meet a range of needs for studying Surface Biology and Geology (SBG). SBG will be the premier integrated observatory for observing the emerging impacts of climate change by characterizing the diversity of plant life and resolving chemical and physiological signatures. It will address wildfire risk, behavior, and recovery as well as responses to hazards such as oil spills, toxic minerals in minelands, harmful algal blooms, landslides, and other geological hazards. The SBG team analyzed needed instrument characteristics (spatial, temporal, and spectral resolutions, measurement uncertainty) and assessed the cost, mass, power, volume, and risk of different architectures. We present an overview of the Research and Applications trade-study analysis of algorithms, calibration and validation needs, and societal applications with specifics of substudies detailed in other articles in this special collection. We provide a value framework to converge from hundreds down to three candidate architectures recommended for development. The analysis identified valuable opportunities for international collaboration to increase the revisit frequency, adding value for all partners, leading to a clear measurement strategy for an observing system architecture.

Observing System↗