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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Modular space station Phase B extension NASA administrator's review

The preliminary design, reference program, costs, and sortie and program options for the modular space station are outlined. The Phase B has a barbell configuration baseline with a manipulator. The baseline includes two capability plateaus, a 6-man station followed after five years by growth to a 12-man station. It is concluded that a common development approach is the most cost effective and flexible system. The system includes a module to support automated payload servicing, a set of sortie labs, and the cargo modules, RAMs, and space station modules. These would be developed and operated in conjunction with the space shuttle.

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NASA NTRS1972

Space station user's handbook

A user's handbook for the modular space station concept is presented. The document is designed to acquaint science personnel with the overall modular space station program, the general nature and capabilities of the station itself, some of the scientific opportunities presented by the station, the general policy governing its operation, and the relationship between the program and participants from the scientific community.

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NASA NTRS1972

Space station data flow

The results of the space station data flow study are reported. Conceived is a low cost interactive data dissemination system for space station experiment data that includes facility and personnel requirements and locations, phasing requirements and implementation costs. Each of the experiments identified by the operating schedule is analyzed and the support characteristics identified in order to determine data characteristics. Qualitative and quantitative comparison of candidate concepts resulted in a proposed data system configuration baseline concept that includes a data center which combines the responsibility of reprocessing, archiving, and user services according to the various agencies and their responsibility assignments. The primary source of data is the space station complex which provides through the Tracking Data Relay Satellite System (TDRS) and by space shuttle delivery data from experiments in free flying modules and orbiting shuttles as well as from the experiments in the modular space station itself.

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NASA NTRS1972

Integrated dynamic analysis simulation of space stations with controllable solar array

A methodology is formulated and presented for the integrated structural dynamic analysis of space stations with controllable solar arrays and non-controllable appendages. The structural system flexibility characteristics are considered in the dynamic analysis by a synthesis technique whereby free-free space station modal coordinates and cantilever appendage coordinates are inertially coupled. A digital simulation of this analysis method is described and verified by comparison of interaction load solutions with other methods of solution. Motion equations are simulated for both the zero gravity and artificial gravity (spinning) orbital conditions. Closed loop controlling dynamics for both orientation control of the arrays and attitude control of the space station are provided in the simulation by various generic types of controlling systems. The capability of the simulation as a design tool is demonstrated by utilizing typical space station and solar array structural representations and a specific structural perturbing force. Response and interaction load solutions are presented for this structural configuration and indicate the importance of using an integrated type analysis for the predictions of structural interactions.

Heinrichs, J. A.↗
NASA NTRS1972

A halo-orbit lunar station.

A relay satellite following a halo trajectory will always maintain line-of-sight contact with the earth and the moon's far side. The Integrated Program Plan for lunar exploration in the 1980s and beyond calls for a fully reusable earth-moon transportation system. The principal elements of the system are a Translunar Shuttle, a Lunar-Orbit Space Station or Halo-Orbit Space Station, and a Lunar Space Tug. It is shown that a halo-orbit space station could offer important operational and performance advantages compared to a lunar-orbit station in a second-generation lunar program.

Farquhar, R. W.↗
NASA NTRS1972

Habitability factors in a rotating space station.

Factors aiding man to adjust to the artificial gravity environment of a rotating space station in orbit are considered. From recent experiments reported by Newsom et al. (1966), it is known that, if man is taken stepwise into a rotating environment, he can adjust (without becoming ill) to spin rates above that required for maintaining an artificial gravity environment in a space station. Little or no data are available, and much work remains to be done in the area of prehabituation and the rate at which habituation is extinguished. At least three factors must be considered in the design of an artificial gravity space station, and these factors directly affect the degree of habitability of the space-station environment. The three factors are rotation rate, stability, and Coriolis force.

Newsom, B. D.↗
NASA NTRS1972

Life support system definition for a low cost shuttle launched space station.

Discussion of the tradeoffs and EC/LS definition for a low cost shuttle launched space station to be launched in the late 1970s for use as a long-term manned scientific laboratory. The space station consists of 14-ft-diam modules, clustered together to support a six-man crew at the initial space station (ISS) level and a 12-man crew at the growth space station (GSS) level. Key design guidelines specify low initial cost and low total program cost and require two separate pressurized habitable compartments with independent lift support capability. The methodology used to select the EC/LS design consisted of systematically reducing quantitative parameters to a common denominator of cost. This approach eliminates many of the inconsistencies that can occur in such decision making. The EC/LS system selected is a partially closed system which recovers urine, condensate, and wash water and concentrates crew expired CO2 for use in a low thrust resistojet propulsion system.

Nelson, W. G.↗
NASA NTRS1972

Station-keeping guidance

The station-keeping guidance system is described, which is designed to automatically keep one orbiting vehicle within a prescribed zone fixed with respect to another orbiting vehicle. The active vehicle, i.e. the one performing the station-keeping maneuvers, is referred to as the shuttle. The other passive orbiting vehicle is denoted as the workshop. The passive vehicle is assumed to be in a low-eccentricity near-earth orbit. The primary navigation sensor considered is a gimballed tracking radar located on board the shuttle. It provides data on relative range and range rate between the two vehicles. Also measured are the shaft and trunnion axes gimbal angles. An inertial measurement unit (IMU) is provided on board the orbiter. The IMU is used at all times to provide an attitude reference for the vehicle. The IMU accelerometers are used periodically to monitor the velocity-correction burns applied to the shuttle during the station-keeping mode. The guidance system is capable of station-keeping the shuttle in any arbitrary position with respect to the workshop by periodically applying velocity-correction pulses to the shuttle.

Gustafson, D. E.↗
NASA NTRS1973

Laser ranging ground station development

The employment of ground to conduct radar range measurements of the lunar distance is discussed. The advantages of additional ground stations for this purpose are analyzed. The goals which are desirable for any new type of ranging station are: (1) full time availability of the station for laser ranging, (2) optimization for signal strength, (3) automation to the greatest extent possible, (4) the capability for blind pointing, (5) reasonable initial and modest operational costs, and (6) transportability to enhance the value of the station for geophysical purposes.

Faller, J. E.↗
NASA NTRS1975

Simultaneous acquisition of tracking data from two stations

A method and apparatus is described for obtaining simultaneous tracking data from two ground stations relative to a spacecraft, and in particular for obtaining two-way range and Doppler measurements with respect to the spacecraft using only one transponder on the spacecraft. The technique employs simultaneous transmission from two stations to produce a return signal with upper and lower sidebands resulting from the interference of the two transmissions. A transponder transmits the upper and lower sidebands centered about a carrier received by both stations. One station tracks the carrier and the other tracks a sideband aided by the carrier.

Wood, G. E.↗
NASA NTRS1974

Earth's gravity field to the eighteenth degree and geocentric coordinates for 104 stations from satellite and terrestrial data

Geodetic parameters describing the earth's gravity field and the positions of satellite-tracking stations in a geocentric reference frame have been computed. These parameters were estimated by means of a combination of five different types of data: routine and simultaneous satellite observations, observations of deep space probes, measurements of terrestrial gravity, and surface triangulation data. The combination gives better parameters than does any subset of data types. The dynamic solution used precision-reduced Baker-Nunn observations and laser range data of 25 satellites. Data from the 49-station National Oceanic and Atmospheric Administration BC-4 network, the 19-station Smithsonian Astrophysical Observatory Baker-Nunn network, and independent camera stations were employed in the geometrical solution.

Gaposchkin, E. M.↗
NASA NTRS1976

Small space station electrical power system design concepts

A small manned facility, i.e., a small space station, placed in earth orbit by the Shuttle transportation system would be a viable, cost effective addition to the basic Shuttle system to provide many opportunities for R&D programs, particularly in the area of earth applications. The small space station would have many similarities with Skylab. This paper presents design concepts for an electrical power system (EPS) for the small space station based on Skylab experience, in-house work at Marshall Space Flight Center, SEPS (Solar Electric Propulsion Stage) solar array development studies, and other studies sponsored by MSFC. The proposed EPS would be a solar array/secondary battery system. Design concepts expressed are based on maximizing system efficiency and five year operational reliability. Cost, weight, volume, and complexity considerations are inherent in the concepts presented. A small space station EPS based on these concepts would be highly efficient, reliable, and relatively inexpensive.

Jones, G. M.↗
NASA NTRS1976

An estimate of the geodetic accuracy attainable with a transportable lunar laser station

A transportable lunar laser ranging station can be expected to measure the range to the lunar corner retroreflectors from a site on the earth's surface with an uncertainty of about 3 cm. The accuracy with which that station can infer its geocentric position is influenced by many factors including the uncertainties in the pole position and rotation rate of the earth and the data loss due to weather. The results of a simplified modeling study intended to include these factors are presented in cartographic form. The modeling indicates that, assuming the successful operation of three or more widely separated fixed laser stations, the transportable station will be able to determine its relative geocentric position in all three coordinates with an accuracy comparable to the original range uncertainty.

Silverberg, E. C.↗
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.↗