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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Station position results using concentrated C-band tracking of GEOS-3

Station positions for the GEOS 3 C Band tracking network were estimated using C Band and laser data taken during a two-week concentrated tracking period. The C Band stations are located primarily in the continental United States and on Western Atlantic islands. The network, however, included stations in Hawaii, in West Germany, and on Kwajalein atoll. Estimated accuracies for the recovered positions are 2 m for the continental U. S. and Atlantic sites, 5 m for Hawaii, and 10 m for Kwajalein. The dominant contributor to these uncertainties is geopotential model error. Thus, the C Band/laser data set could be used for more accurate center-of-mass positioning of a continental network of stations.

Krabill, W. B.↗
NASA NTRS1979

LS47: A DSN station location set compatible with JPL development ephemeris DE108

An updated Deep Space Network station location set, LS47, is presented which is compatible with JPL Development Ephemeris DE108. Analytic procedures for linearly correcting station spin axis and longitude estimates for an ephemeris update based on Brouwer-Clemence Set III parameters are briefly discussed. The validity of this technique is demonstrated by a comparison of a linearly corrected solution with one explicitly determined by reprocessing the data. A mission data base, including Viking 1 and 2 encounter data, is first used to obtain an updated DE96 compatible station location solution, LS46, which in turn is adjusted to form the DE108 solution, LS47. Improved station Z-heights are estimated by using available very long baseline interferometry data. Spin axis differences between LS46 and LS47 are relatively insignificant; however, the ephemeris change introduces a -0.8 x 10 to the -5 power degree rotation in the DE96 longitude ephemeris.

Ellis, J.↗
NASA NTRS1979

Orbiting Deep Space Relay Station (ODSRS). Volume 1: Requirement determination

The deep space communications requirements of the post-1985 time frame are described and the orbiting deep space relay station (ODSRS) is presented as an option for meeting these requirements. Under current conditions, the ODSRS is not yet cost competitive with Earth based stations to increase DSN telemetry performance, but has significant advantages over a ground station, and these are sufficient to maintain it as a future option. These advantages include: the ability to track a spacecraft 24 hours per day with ground stations located only in the USA; the ability to operate at higher frequencies that would be attenuated by Earth's atmosphere; and the potential for building very large structures without the constraints of Earth's gravity.

Hunter, J. A.↗
NASA NTRS1979

Interim radio spectrum surveillance station

Radio frequency interference at NASA's deep space stations has become a serious problem. A radio spectrum surveillance capability at these stations is needed to determine the sources of interference so that preventative measures can be taken. The first phase of a program to develop this capability was the development of a low-cost surveillance station now in operation at the Goldstone Space Communication Complex near Barstow, California. This interim surveillance station is described and findings from the use of this equipment are presented.

Hersey, D. R.↗
NASA NTRS1980

Deep Space Station (DSS-13) automation demonstration

The data base collected during a six month demonstration of an automated Deep Space Station (DSS 13) run unattended and remotely controlled is summarized. During this period, DSS 13 received spacecraft telemetry data from Voyager, Pioneers 10 and 11, and Helios projects. Corrective and preventive maintenance are reported by subsystem including the traditional subsystems and those subsystems added for the automation demonstration. Operations and maintenance data for a comparable manned Deep Space Station (DSS 11) are also presented for comparison. The data suggests that unattended operations may reduce maintenance manhours in addition to reducing operator manhours. Corrective maintenance for the unmanned station was about one third of the manned station, and preventive maintenance was about one half.

Remer, D. S.↗
NASA NTRS1979

Radio spectrum surveillance station

The paper presents a general and functional description of a low-cost surveillance station designed as the first phase of NASA's program to develop a radio spectrum surveillance capability for deep space stations for identifying radio frequency interference sources. The station described has identified several particular interferences and is yielding spectral signature data which, after cataloging, will serve as a library for rapid identification of frequently observed interference. Findings from the use of the station are discussed.

Hersey, D. R.↗
NASA NTRS1983

Space station needs, attributes and architectural options study. Volume 5: Cost benefits and programmatic analyses

The science, applications, commercial, U.S. national security and space operations missions that would require or be materially benefited by the availability of a permanent manned space station in low Earth orbit are considered. Space station attributes and capabilities which will be necessary to satisfy these mission requirements are identified. Emphasis is placed on the identification and validation of potential users, their requirements, and the benefits accruing to them from the existence of a space station, and the programmatic and cost implications of a space station program.

Source record↗
NASA NTRS1983

Application of a space station to communications satellites

The economic benefits of a space station relative to communications satellites are discussed in terms of technology experiments, spacecraft checkout, repair, servicing, and refurbishment (RSR), and mating an OTV with satellites for boost to GEO. The zero gravity, vacuum conditions, and atmosphere free long ranges are environmental features that can be used for testing large, flexible antennas and laser communications devices. Some resistance might be encountered to checkout in LEO due to the substantial success of launches to GEO without LEO checkout. However, new generations of larger, more complex satellites may warrant the presence of a space station to verify performance of new spacecraft. One RSR positive aspect for a space station is as a storage site for propellant, as well as for reusable OTV booster engines. Also, the space station can serve as a base for manned or unmanned repair spacecraft which will travel to GEO to fix malfunctions in geostationary satellites.

Ramler, J. R.↗
NASA NTRS1983

Autonomy issues for an operational space station

Within the last decade, both the U.S. and the Soviet space programs have taken significant preliminary steps in developing technology and systems which are appropriate for the establishment of space stations. The degree of autonomy which will be provided for the station and the role of the crew represents one of the most critical considerations. The present investigation is concerned with a review of the major autonomy issues associated with a permanent, low earth orbit, operational space station. It is shown that both operational effectiveness and crew safety issues require a relatively high degree of space station autonomy. The autonomy level should, for instance, be higher than that of the present space shuttle. Attention is given to various levels of spacecraft autonomy, system integrity, attitude determination and control, navigation and orbit maintenance, system maintenance and resupply, mission support, and implementation of autonomy.

Daly, K. C.↗
NASA NTRS1983

On-board estimation technology for space station - Current status and future developments.

Design considerations and projected solutions to on-board automated estimation techniques for advanced technology controls on a space station are described, with emphasis on the state estimator. The space station is modelled as a collection of rigid and flexible bodies connected at a finite number of hinges. The systems dynamics are characterized by angular velocities of the base body, gimbal angles, and deflections of the flexible appendages. The state estimator evolution is projected to occur in four generations, with the first being control logic in the Viking and Voyager spacecraft, the second in the Shuttle and Galileo probe, the third being large antennas and the prototype space station, the last, around the year 2000, for the actual space station. Considerations for attitude, ephemeris, shape determination, and position estimation through each generation are discussed.

Rodriguez, G.↗
NASA NTRS1983

The US space station: Potential base for a spaceborne microwave facility

Concepts for a U.S. space station were studied to achieve the full potential of the Space Shuttle and to provide a more permanent presence in space. The space station study is summarized in the following questions: Given a space station in orbit in the 1990's, how should it best be used to achieve science and applications objectives important at that time? To achieve those objectives, of what elements should the station be comprised and how should the elements be configured and equipped. These questions are addressed.

Mcconnell, D.↗
NASA NTRS1983

Space station needs, attributes and architectural options study. Volume 4: Architectural options, subsystems, technology and programmatics

Space station architectural options, habitability considerations and subsystem analyses, technology, and programmatics are reviewed. The methodology employed for conceiving and defining space station concepts is presented. As a result of this approach, architectures were conceived and along with their supporting rationale are described within this portion of the report. Habitability consideration and subsystem analyses describe the human factors associated with space station operations and includes subsections covering (1) data management, (2) communications and tracking, (3) environmental control and life support, (4) manipulator systems, (5) resupply, (6) pointing, (7) thermal management and (8) interface standardization. A consolidated matrix of subsystems technology issues as related to meeting the mission needs for a 1990's era space station is presented. Within the programmatics portion, a brief description of costing and program strategies is outlined.

Source record↗
NASA NTRS1983

Space Station needs, attributes and architectural options. Volume 2, book 2, part 2, Task 2: Information management system

Missions to be performed, station operations and functions to be carried out, and technologies anticipated during the time frame of the space station were examined in order to determine the scope of the overall information management system for the space station. This system comprises: (1) the data management system which includes onboard computer related hardware and software required to assume and exercise control of all activities performed on the station; (2) the communication system for both internal and external communications; and (3) the ground segment. Techniques used to examine the information system from a functional and performance point of view are described as well as the analyses performed to derive the architecture of both the onboard data management system and the system for internal and external communications. These architectures are then used to generate a conceptual design of the onboard elements in order to determine the physical parameters (size/weight/power) of the hardware and software. The ground segment elements are summarized.

Source record↗
NASA NTRS1983

Alternative strategies for space station financing

The attributes of the proposed space station program are oriented toward research activities and technologies which generate long term benefits for mankind. Unless such technologies are deemed of national interest and thus are government funded, they must stand on their own in the market place. Therefore, the objectives of a United States space station should be based on commercial criteria; otherwise, such a project attracts no long term funding. There is encouraging evidence that some potential space station activities should generate revenues from shuttle related projects within the decade. Materials processing concepts as well as remote sensing indicate substantial potential. Futhermore, the economics and thus the commercial feasibility of such projects will be improved by the operating efficiencies available with an ongoing space station program.

Walklet, D. C.↗
NASA NTRS1984

Dynamic characteristics of a space-station solar wing array

A solar-wing-array concept is described which meets space-station requirements for minimum fundamental frequency (0.4 Hz), component modularity, and growth potential. The basic wing-array design parameters are varied, and the resulting effects on the array vibration frequencies and mode shapes are assessed. The transient response of a free-free space station (incorporating a solar-wing-array point design) to a load applied at the space-station center is studied. The use of the transient response studies in identifying critically loaded structural members is briefly discussed. The final 150-kW space-station configuration has a fundamental elastic frequency of 0.403 Hz.

Dorsey, J. T.↗
NASA NTRS1983

Space station needs, attributes, and architectural options: Mission requirements

Space station missions and their requirements are discussed. Analyses of the following four mission categories are summarized: (1) commercial, (2) technology, (3) operation, and (4) science and applications. The requirements determined by the study dictate a very strong need for a manned space station to satisfy the majority of the missions. The station is best located at a 28.5-deg inclination and initially (1992 era) requires a crew of four (three for mission payloads) and a mission power of 25 kW. A space platform in a polar orbit is needed to augment the station capability; it initially would be a 15-kW system, located in a sun-synchronous orbit.

Riel, F. D.↗
NASA NTRS1983

Space station needs, attributes and architectural options. Volume 4, task 2 and 3: Mission implementation and cost

An overview of the basic space station infrastructure is presented. A strong case is made for the evolution of the station using the basic Space Transportation System (STS) to achieve a smooth transition and cost effective implementation. The integrated logistics support (ILS) element of the overall station infrastructure is investigated. The need for an orbital transport system capability that is the key to servicing and spacecraft positioning scenarios and associated mission needs is examined. Communication is also an extremely important element and the basic issue of station autonomy versus ground support effects the system and subsystem architecture.

Source record↗
NASA NTRS1984

Space station

The need for a space station, its cost, its use, and completion are examined. The Space Station Task Force was established by NASA Administrators to answer questions and to provide focus and direction for Space Station planning activities. The task force provides Congress and the Administration with sufficient information to make decisions on whether the United States should proceed with a Space Station as the next major national initiative in space. Current thinking on selected issues, planning guidelines, unique considerations and organization are presented.

Forestieri, A. F.↗