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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Geometric adjustment of the South American satellite densification (PC-1000) network

Reduced normal equations were computed from observation data and combined with reduced normal equations of other satellite networks to provide station coordinates from a single least square adjustment. Terrestrial data, which include base-lines, heights, and survey coordinates, provide the necessary relative position constraints between collocated stations of two satellite networks. Survey information regarding the observation stations is summarized, and constraints used in the solution are given. Geoidal undulations are computed by using the formula and constants shown.

Mueller, I. I.↗
NASA NTRS1977

Vibration-resistant PC board feedthrough

New fabrication method uses annealed-nickel ribbon loop to interface coaxial input (or output) connector to printed-wiring board. Inexpensive ribbon interface cuts vibration-induced failure between coaxial cable and printed-wiring board.

Mandel, H.↗
NASA NTRS1977

A statistical study of Pc 3 magnetic pulsations at synchronous orbit, ATS 6

Results are reported for a study designed to determine statistically the nature and variation of the polarization parameters of Pc3 magnetic pulsations at synchronous orbit. Data obtained with a triaxial flux gate magnetometer on the geosynchronous satellite ATS 6 are subjected to routine power spectral and polarization analyses, and the events examined are identified as peaks in the spectra. Coherence analysis of spectral matrices for these events indicates that Pc3 are very common at synchronous orbit and are primarily a local morning phenomenon with an occurrence peak around 1000 LT; that the pulsations occur at all frequencies in the Pc3 band, with the most common frequency at about 0.35 Hz; that the Pc3 at synchronous orbit are most often linear and generally transverse, but some have significant compressional components; and that based on azimuth angle, there are two distinct classes of Pc3 (azimuthal and radial) with different characteristics. These statistical results are compared with model predictions and ground-based observations.

Arthur, C. W.↗
NASA NTRS1978

Bench-top soldering aid for PC boards

Multiple-board rack allows technician to insert components into several boards, flip them all in single motion, and then systematically solder leads on reverse side. Two adjustable crossbars allow boards of any size up to 10 by 24 inches. Operator can rotate racks and adjust angle of boards from standing or sitting position.

Manton, N. R.↗
NASA NTRS1980

Securing connector pins to a PC board

Solder preforms hold pins firmly to withstand repeated insertion and removal of circuit cards. Advantage is excellent electrical continuity between board circuits and pins.

Graham, D.↗
NASA NTRS1978

PC-403: Pioneer Venus multiprobe spacecraft mission operational characteristics document, volume 1

The operational characteristics of the multiprobe system and its subsystem are described. System level, description of the nominal phases, system interfaces, and the capabilities and limitations of system level performance are presented. Bus spacecraft functional and operational descriptions at the subsystem and unit level are presented. The subtleties of nominal operation as well as detailed capabilities and limitations beyond nominal performance are discussed. A command and telemetry logic flow diagram for each subsystem is included. Each diagram identifies in symbolic logic all signal conditioning encountered along each command signal path into, and each telemetry signal path out of the subsystem.

Barker, F. C.↗
NASA NTRS1978

PC-403: Pioneer Venus multiprobe spacecraft mission operational characteristics document, volume 3

The Pioneer Venus spacecraft primary and backup operational modes and operational limitations for maneuvers, roll references transfer, attitude determination, spacecraft power discipline and spacecraft thermal discipline, are described. The functions and operations of the large and small probes, as well detailed performance in the normal operating modes and backup modes are presented.

Barker, F. C.↗
NASA NTRS1978

PC-402 Pioneer Venus orbiter spacecraft mission operational characteristics document

The operational characteristics of the Orbiter spacecraft and its subsystems are described. In extensive detail. Description of the nominal phases, system interfaces, and the capabilities and limitations of system level performance are included along with functional and operational descriptions at the subsystem and unit level the subtleties of nominal operation as well as detailed capabilities and limitations beyond nominal performance are discussed. A command and telemetry logic flow diagram for each subsystem is included. Each diagram encountered along each command signal path into, and each telemetry signal path out of the subsystem. Normal operating modes that correspond to the performance of specific functions at the time of specific events in the mission are also discussed. Principal backup means of performing the normal Orbiter operating modes are included.

Barker, F. C.↗
NASA NTRS1984

Asynchronous file transfer to IBM PC's

The Asynchronous File Transfer System is used for interactively selecting and tramsmitting text files from the Langley Research Center's Business Data Systems Division (BDSD) host processor to an IBM Personal Computer. The IBM asynchronous communications support package is used for handling the communications on the personal computer. An application program (NATURAL, COBOL, etc.) is used for selecting and formatting the records to be transmitted, and three subroutine modules residing on the BDSD host processor are used for interfacing the application program and the communications software. Each record transmitted to the Personal Computer must be in the standard ASCII format. This record format is directly accessible by BASIC and many of the personal computer software packages provide utility programs for converting them to the format required for the particular package in question.

Hoerger, J.↗
NASA NTRS1986

An IBM PC-based math model for space station solar array simulation

This report discusses and documents the design, development, and verification of a microcomputer-based solar cell math model for simulating the Space Station's solar array Initial Operational Capability (IOC) reference configuration. The array model is developed utilizing a linear solar cell dc math model requiring only five input parameters: short circuit current, open circuit voltage, maximum power voltage, maximum power current, and orbit inclination. The accuracy of this model is investigated using actual solar array on orbit electrical data derived from the Solar Array Flight Experiment/Dynamic Augmentation Experiment (SAFE/DAE), conducted during the STS-41D mission. This simulator provides real-time simulated performance data during the steady state portion of the Space Station orbit (i.e., array fully exposed to sunlight). Eclipse to sunlight transients and shadowing effects are not included in the analysis, but are discussed briefly. Integrating the Solar Array Simulator (SAS) into the Power Management and Distribution (PMAD) subsystem is also discussed.

Emanuel, E. M.↗
NASA NTRS1987

PC 0910 + 5625 - An optically selected quasar with a redshift of 4.04

The discovery of the second quasar with a redshift greater than 4 is reported. This object, which has an r magnitude of 21.0, was detected on a CCD grism survey. The spectrum of the quasar has strong, relatively narrow (but resolved) emission lines; there is a deep absorption trough about 100 A wide on the blue wing of the Lyman-alpha line; and the continuum at wavelengths shorter than the absorption feature is far weaker than the level present redward of Lyman-alpha.

Schmidt, Maarten↗