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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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Hubble Space Telescope servicing - Experience base for a new era

An account is given of the conceptual evolution of the Hubble Space Telescope's (HST) maintenance methodology, and the belated recognition of its long-term support requirements, as well as measures conceived for the extension of this orbiting observatory's service life, and the prospective benefits derivable by comparable programs from HST experience. Attention is given to HST cost and capability tradeoffs, the maintenance concept's definition, the integrated logistic support planning instituted by the program and its failure-prediction methods, as well as the institutional support base employed.

Welch, James C.↗
NASA NTRS1987

Space Network mission support in the Space Station era

The Mission Model for user support and NASA's plans to provide the necessary support resources are discussed. Particular attention is given to considerations which imply operation of up to two additional Tracking and Data Relay Satellites (TDRS), as well as potential interoperability with data relay satellite systems planned for launch in the mid-1990s by the ESA and by the NASDA of Japan. NASA activities related to the development of an Advanced TDRS system for the support of missions flying in the 21st century are also discussed.

Harris, David W.↗
NASA NTRS1988

OSSA's Telescience concept for the Space Station era

NASA's Office of Space Science and Applications has formulated an operational concept, 'telescience', for Space Station-related missions; telescience encompasses teledesign, teleoperations, teleanalysis, and an overall integrating structure that defines and delineates the system's architectural infrastructure and networking for implementation. Attention is here given to the development status of data interchange standards, interoperable networks, automated data-ingest mechanisms and access directories, means to the accessing of heterogeneous data bases, and user-support environments.

Weiss, James R.↗
NASA NTRS1988

A telescope for high energy gamma-ray measurements in the Space Station era

This paper describes the concept of a large gamma-ray imaging telescope system (GRITS) which will provide sufficient sensitivity for the identification of faint objects to be catalogued by the Gamma-Ray Observatory. The technique used in this telescope for the detection of gamma rays is based on the conversion of the incident gamma ray into an electron-positron pair which subsequently produces Cherenkov radiation. The gamma ray is identified by a unique signature based on a sequence of time-delayed coincidence events. The GRITS telescope will use the extended Shuttle external tank, ET, as the pressure vessel necessary for the gas-Cherenkov process. Astronauts from the Shuttle or the Space Station performing EVA will convert ET to an autonomous spacecraft and install the telescope inside the ET.

Koch, David G.↗
NASA NTRS1987

Space 2000: Meeting the challenge of a new era

The focus of the present book is on the variety of past and future human activities in space. NASA's response to the Challenger explosion is discussed and an overview is given of the agency's relations with foreign competitors in the 1980s. The practical uses of space are described with attention given to communications satellites, the orbital high ground (weather watching, spying, and SDI), earth science, and materials processing in space. Other topics include the exploration of the near and distant universe, and permanent stations in space and on the moon.

Shipman, Harry L.↗
NASA NTRS1989

Remote sensing information sciences research group: Browse in the EOS era

The problem of science data browse was examined. Given the tremendous data volumes that are planned for future space missions, particularly the Earth Observing System in the late 1990's, the need for access to large spatial databases must be understood. Work was continued to refine the concept of data browse. Further, software was developed to provide a testbed of the concepts, both to locate possibly interesting data, as well as view a small portion of the data. Build II was placed on a minicomputer and a PC in the laboratory, and provided accounts for use in the testbed. Consideration of the testbed software as an element of in-house data management plans was begun.

Estes, John E.↗
NASA NTRS1988

Telescience in the Space Station era

Telescience refers to the development of systems where participants involved in research in space can access their fellow scientists and the appropriate NASA services before flight, during flight, and after flight, preferably from their home institutions and through the same equipment. Telescience requires integration of available technologies to develop computer environments that maintain interoperability across different disciplines and different portions of the lifetimes of space experiments, called teledesign, teleoperations, and teleanalysis. Participants in the NASA Telescience Testbed Program are using a rigid prototyping approach to evaluate the necessary technologies and select the options and tradeoffs that best suit their accustomed modalities. The concept of transaction management is described, where the emphasis is placed on the effects of commands, whether event-generated onboard the spacecraft or sent up from the ground. Interoperability, security, and privacy issues are also discussed, and the Telescience Testbed Pilot Program is described.

Schmerling, E. R.↗
NASA NTRS1989

Facilitating information transfer in the EOS era

A simple interactive demonstration program has been written in C to allow a user to input data field descriptions as label format. This program generates a full RECFMT (record format) description and the complete transfer syntax description notation (TSDN) file. It is intended that this program be upgraded to operational quality and be made available to users to simplify the description and TSDN file construction task. The total set of capabilities, from the standard formatted data unit packaging of related files and consistent segment structures, through the type definition techniques and the call server, will constitute a unique tool for the systematic transfer of data. This software on each end may be independent, one end from the other. With it available, local software that will be needed to convert user files to and from the canonical interface will be appreciably simplified.

Billingsley, Frederic C.↗
NASA NTRS1989

Land image data processing requirements for the EOS era

Requirements are proposed for a hybrid approach to image analysis that combines the functionality of a general-purpose image processing system with the knowledge representation and manipulation capabilities associated with expert systems to improve the productivity of scientists in extracting information from remotely sensed image data. The overall functional objectives of the proposed system are to: (1) reduce the level of human interaction required on a scene-by-scene basis to perform repetitive image processing tasks; (2) allow the user to experiment with ad hoc rules and procedures for the extraction, description, and identification of the features of interest; and (3) facilitate the derivation, application, and dissemination of expert knowledge for target recognition whose scope of application is not necessarily limited to the image(s) from which it was derived.

Wharton, Stephen W.↗
NASA NTRS1989

How tethered systems can benefit microgravity research in the Space Station era

The use of a tethered movable orbiting laboratory for microgravity research is examined. The relation between reduced microgravity carriers and acceleration levels, and the effects of acceleration levels on in-orbit experiments are studied. The tuning of the gravity level at a space laboratory by employing a tether is described. The applications of the variable gravity environment to research in fluids and materials sciences, life sciences, separative techniques, and physical and applied chemistry are discussed.

Lavitola, Maria Stella↗
NASA NTRS1989

A brief history of magnetospheric physics before the spaceflight era

Early research on the earth's magnetic environment is reviewed, with attention given to the period when only ground-based observations were possible. Early work on geomagnetism is discussed as well as the sunspot cycle, solar fares, the possibility of electron beams from the sun, and the Chapman-Ferraro cavity. Consideration is also given to the ring current, Alfvens theory and electric fields, interplanetary plasma, and polar magnetic storms.

Stern, David P.↗
NASA NTRS1988

Space tethers for science in the space station era; Proceedings of the Second International Conference, Venice, Italy, Oct. 4-8, 1987

Various papers on space tethers are presented. The general topics addressed include: the space program context for tethers, early experimental validation of tethers, tether dynamics simulations, electrodynamics aspects of tethers, and tethers for science and innovative uses. Also considered are: tethers in space, tether dynamics, tethers on stations and platforms, and tether technology.

Guerriero, Luciano↗
NASA NTRS1990

Mark 4-A DSCC (Magellan-era) telemetry system description

An update to the description of the Deep Space Communications Complex portion of the Mark 4-A Telemetry system is given. This system is currently implemented at all signal processing centers. The upgrade of the telemetry system was undertaken primarily in support of the Voyager-Neptune Encounter and the Magellan mission. The Mark 3 Telemetry System is the predecessor of the Mark 4-A system.

Ross, D. L.↗
NASA NTRS1989

Microgravity research in the era of Space Station Freedom

NASA has developed numerous microgravity research-related missions planned for the period of 1991 to 1994, leading to Space Station Freedom (SSF). Space Transportation System (STS) flights are designed with the philosophy that STS, Spacelab, and SSF will constitute an integrated system allowing an evolutionary approach to microgravity research in low earth orbit. Ground experiments, tested and refined on short-duration STS flights, will be developed and deployed on SSF where long-duration operation is required. In addition, this sequence will ensure maximum scientific return, encourage growth of the research community, and increase the chances of identifying new techniques and processes to be used in the SSF time frame. The paper discusses the rationale, justification, and approach taken by NASA to fully exploit this environment.

Lee, Mark C.↗
NASA NTRS1989

A spectral feature design system for the HIRIS/MODIS era

A spectral feature design system for high-dimensional multispectral data is described. This system utilizes hard-limited or infinitely clipped optimal transforms and canonical analysis to extract the spectral features for data volume reduction and classification purposes. The design procedure is intended to be application-specific in order to make it maximally effective for each use. Although it could be used in a variety of circumstances, the procedure was designed with satellite data collection in mind, such as will be needed with the High-Resolution Imaging Spectrometer (HIRIS), a land-oriented Earth observational sensor intended for launch in the mid-1990s. The computation required for the steps prior to the actual satellite data collection are straightforward and could be done with readily available subroutines. The procedure is also defined in such a way as to require only very simple onboard calculations. The tests reported provide substantial data volume reduction in the satellite-to-Earth downlink and subsequent computation phases, while maintaining satisfactory classification accuracy.

Chen, Chih-Chien Thomas↗
NASA NTRS1989

On developing the local research environment of the 1990s - The Space Station era

A requirements analysis for the Space Station's polar platform data system has been performed. Based upon this analysis, a cluster, layered cluster, and layered-modular implementation of one specific module within the Eos Data and Information System (EosDIS), an active data base for satellite remote sensing research has been developed. It is found that a distributed system based on a layered-modular architecture and employing current generation work station technologies has the requisite attributes ascribed by the remote sensing research community. Although, based on benchmark testing, probabilistic analysis, failure analysis and user-survey technique analysis, it is found that this architecture presents some operational shortcomings that will not be alleviated with new hardware or software developments. Consequently, the potential of a fully-modular layered architectural design for meeting the needs of Eos researchers has also been evaluated, concluding that it would be well suited to the evolving requirements of this multidisciplinary research community.

Chase, Robert↗
NASA NTRS1990

Role of communications satellites in the fiber era

Systenm descriptions of satellite and fiber optic networks are developed for the benchmark years 1983 and 1986, and forecasts are made for the years 1990 and 1995. Based on this information, the impact of fiber optics on satellite communications in the years 1995 and 2000 is assessed. Ten services are identified which are likely to be supplied at least in part by satellite in the 1995-2000 time frame. Estimates are made of the probability of existence and the number of transponders used by these future satellite services.

Price, Kent M.↗
NASA NTRS1989

Telemetry data storage systems technology for the Space Station Freedom era

This paper examines the requirements and functions of the telemetry-data recording and storage systems, and the data-storage-system technology projected for the Space Station, with particular attention given to the Space Optical Disk Recorder, an on-board storage subsystem based on 160 gigabit erasable optical disk units each capable of operating at 300 M bits per second. Consideration is also given to storage systems for ground transport recording, which include systems for data capture, buffering, processing, and delivery on the ground. These can be categorized as the first in-first out storage, the fast random-access storage, and the slow access with staging. Based on projected mission manifests and data rates, the worst case requirements were developed for these three storage architecture functions. The results of the analysis are presented.

Dalton, John T.↗