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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Tesseral resonance on IMP-4 orbit

Tesseral harmonics of Explorer 34 satellite orbit perturbation in time of perigee passage due to third harmonic of earth gravitational field

Lowrey, B. E.↗
NASA NTRS1971

Solar proton, helium, and medium nuclei (Z is equal to or greater than 6 and equal to or less than 9) observed from the IMP-6 satellite

Proton, helium, and medium nuclei energy spectra have been measured from the Explorer 35 satellite for a recent solar flare. Above 2 MeV/nucleon these spectra are based upon single and dual parameter pulse height analysis in addition to threshold rate counting. Pulse height analysis of medium nuclei is assigned a high priority for telemetry readout so that telemetry does not become saturated by the high proton intensity. In this manner the number of pulse height analyzed medium nuclei has been increased by a factor of approximately 200. Individual medium nuclei have been resolved in the energy interval 8 - 23 MeV/nucleon.

Vonrosenvinge, T. T.↗
NASA NTRS1971

Spacecraft orbit/earth scan derivations, associated APL program, and application to IMP-6

The derivation of a time shared, remote site, demand processed computer program is discussed. The computer program analyzes the effects of selected orbit, attitude, and spacecraft parameters on earth sensor detections of earth. For prelaunch analysis, the program may be used to simulate effects in nominal parameters which are used in preparing attitude data processing programs. After launch, comparison of results from a simulation and from satellite data will produce deviations helpful in isolating problems.

Smith, G. A.↗
NASA NTRS1971

Instrumentation for radio astronomy measurements aboard the IMP-I spacecraft

The design considerations and performance parameters of a satellite-borne instrumentation system are discussed. The system is designed to make radio astronomy measurements at eight discrete frequencies from 50 kHz to 3.53 MHz. These measurements are to detect solar and Jovian radio frequency bursts and to determine the average cosmic background radiation level down to 50 kHz. Procedures used for preflight and inflight calibration of the radiometer and the ground support equipment used for preflight testing are described.

Haddock, F. T.↗
NASA NTRS1972

An approach to attitude determination for a spin-stabilized spacecraft (IMP 1)

The analysis and the FORTRAN program are presented for the determination of attitude of a spin-stabilized spacecraft. The use of telemetry data that provide information about two reference vectors and their relation to the spin is outlined. A technique for the determination of the spin-axis orientation that employs only simple calculations is described.

Fang, A. C.↗
NASA NTRS1972

Measurement of the degree of anisotropy of the cosmic radiation using the IMP space vehicle

The detector and data reduction techniques used in connection with the cosmic ray experiments designed for and flown on Explorer 34 and 41 satellites are described. A history of the program development and the present status of data processing are briefly summarized. The instrument to measure the anisotropy and energy spectra of cosmic ray electrons and protons, and X-rays of solar and galactic origin is discussed. The main characteristics of the detectors and the stability during 23 months of operation are described. The method of analysis of the angular distribution of solar cosmic ray particles in the ecliptic plane is given. It is shown that the anisotropy of low energy particles of solar origin decreases sharply to a very small value when the satellite penetrates the magnetosphere.

Palmeira, R. A. R.↗
NASA NTRS1973

IMP-J attitude control prelaunch analysis and operations plan

A description of the attitude control support being supplied for the Explorer 50 mission is given. Included in the document are descriptions of the computer programs being used to support attitude determination, prediction, and control for the mission and descriptions of the operating procedures that will be used to accomplish mission objectives.

Hooper, H. L.↗
NASA NTRS1973

Analysis of Imp-C data from the magnetospheric tail

Satellite magnetic field measurements in the geomagnetic tail current sheet are analyzed to determine the normal field component, and other CS parameters such as thickness, motion, vector current density, etc., and to make correlations with auroral activity as measured by the A sub e index. The satellite data used in the initial part of this study were from Explorer 28 and Explorer 34 satellites.

Speiser, T. W.↗
NASA NTRS1974

Observations of cosmic gamma-ray bursts with IMP-7: Evidence for a single spectrum

Spectral observation of nine recent cosmic gamma-ray bursts are reported. The average photon number spectra of all nine events are shown to be consistent with a 150-keV exponential from 100 keV to about 400 keV, and a power law of index -2.5 from 400 keV to 1100 keV. The observations also indicate an event rate of 16 in 1972 and 1973, or 8 + or - 2 per year, higher than the 5 + or - 1 per year initially reported. This corresponds to an approximately 40-percent lower effective intensity threshold, attained by using more sensitive detectors in multiple-satellite coincidence.

Cline, T. L.↗
NASA NTRS1975

Observations of cosmic gamma-ray bursts with IMP-7 - Evidence for a single spectrum

Spectral observations of nine recent cosmic gamma-ray bursts are reported. The average photon number spectra of all nine events are each consistent with a 150-keV exponential from 100 keV to about 400 keV, and a power law of index -2.5 from 400 keV to 1100 keV. The observations also indicate an event rate of 16 in 1972 and 1973, or 8 plus or minus 2 per year, higher than the 5 plus or minus 1 per year initially reported. This corresponds to an approximately 40 percent lower effective intensity threshold, attained by using more sensitive detectors in multiple-satellite coincidence.

Cline, T. L.↗
NASA NTRS1976

Observations of magnetospheric bursts of high-energy protons and electrons at approximately 35 earth radii with Imp 7

Proton and electron bursts (above 0.29 MeV and above 0.22 MeV, respectively) in the vicinity of the magnetosphere are studied on the basis of a high-sensitivity experiment. Although the bursts are a permanent feature in the upstream solar wind, the range of observed intensities varies by at least 5 orders of magnitude, depending on magnetic activity. The bursts are typically associated with weak fluctuations in the interplanetary magnetic field, which suggests the presence of hydromagnetic waves. Burst are found in and about the magnetosheath, plasma sheet, and magnetotail boundary layer, and also outside the bow shock; however, they rarely appear at distances greater than 10 earth radii north or south of the neutral sheet. Dawn-dusk asymmetries are present in intensity but not necessarily in frequency of occurrence. Proton bursts are highly anisotropic upstream from the bow shock and in the magnetosheath, while electron bursts are anisotropic only in the upstream solar wind.

Sarris, E. T.↗