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Opp, A. G.

Publications and source records attributed to Opp, A. G..

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Scientific results from the Pioneer Saturn encounter - Summary

The scientific results of the Pioneer Saturn encounter with Saturn are summarized. The Pioneer mission was designed to image the planet, its satellites and rings, and measure its particulate environment and the magnetic field and photon and charged particle radiation by means of 11 operational scientific instruments and its 2.293-GHz telemetry carrier signal. Principle results of the mission include the discovery of an additional ring and a previously unidentified satellite, the further characterization of the physical properties of Saturn and its magnetic field, and the description of the planetary magnetosphere. The successful completion of the mission demonstrated the ability of spacecraft such as Voyager 1 and 2 to survive the particle environments of Saturn's rings and trapped radiation environments, and Pioneer Saturn is expected to continue transmitting information on the interplanetary medium and the solar wind interaction with the interstellar medium until the mid-1980's.

Opp, A. G.↗
NASA NTRS1978

The gamma ray observatory

A large, free-flying space observatory is planned for (1) locating and characterizing gamma ray sources, in particular peculiar objects such as pulsars; (2) studying diffuse gamma ray emission, both from our galaxy and from extragalactic space, (3) investigating other galaxies, especially radio galaxies, Seyfert galaxies and QSOs; and (4) understanding the origin of gamma ray bursts. The spacecraft will weight about 10,000 kg, with about 6,500 kg available for scientific instruments, providing about 400 watts of power to the instruments, and about 12,000 bits per second of telemetry. The spacecraft which will be launched by the space shuttle into a 400 to 500 km circular orbit, inclined at 28.5 deg to the equator, will be three-axis stabilized, with orientation capability of about 20 arc minutes and aspect determination of 2 arc minutes. Absolute timing of 0.1 millisecond will be provided by the spacecraft. The instruments will be co-aligned along one axis of the spacecraft to optimize the spectral coverage of a particular region. A two-year mission is planned with launch in 1984. Possible retrieval by the shuttle at the end of the mission is considered.

Opp, A. G.↗
NASA NTRS1975

Scientific results from the Pioneer 11 mission to Jupiter

Results concerning the magnetosphere, the magnetic field, and the radiation belts of the planet Jupiter obtained by Pioneer 10 were supplemented by the observations made during the passage of Pioneer 11. Pioneer 11 provided further evidence that the disk model is inadequate as a description of the Jovian magnetosphere. The new data have made it possible to develop a field model based on an internal dipole, quadrupole, and possibly octopole and an external dipole and quadrupole.

Opp, A. G.↗
NASA NTRS1975

Current cosmic-ray programs in the United States

Approved NASA cosmic ray programs for the next five years are reviewed. In deep space, four new missions are planned. The first two, Helios A and B, will go inwards to approximately 0.3 AU, and the second two, Mariner Jupiter-Saturn, will go outwards to Saturn at 9.5 AU. Two missions in the earth orbital program promise to provide major new information on cosmic ray isotopes and on very heavy cosmic rays. These are the C mission of the International Sun-Earth Explorer, and the C mission of the High Energy Astronomy Observatory. The balloon research program is also mentioned.

Opp, A. G.↗
NASA NTRS1974

Pioneer 10 mission - Summary of scientific results from the encounter with Jupiter

Data on the Jovian atmosphere and radiation environment transmitted by Pioneer 10 as it passed by Jupiter are discussed. The presence of a strong magnetic field, of energetic electron precursers, and of flat disk-shaped particle distribution is noted at a distance of 360 Jovian radii from the planet. Previously available data on Jovian satellites are augmented from Pioneer 10 data. The normal operation of the data collecting and transmitting systems of the mission after encounter with Jupiter is noted.

Opp, A. G.↗
NASA NTRS1971

Instrumentation for the measurement of high energy phenomena on NASA spacecraft.

High energy astrophysical observations will be conducted primarily from the Small Astronomy Satellites (SAS) and the High Energy Astronomy Observatories (HEAO). The first satellite (SAS A) will carry a set of collimated proportional counters to conduct a high sensitivity, high spatial resolution, all sky survey for X-ray sources. The objective of SAS B will be to search for celestial gamma-ray sources and regions and to measure the flux and energy spectrum of any sources located. A wire grid digitized spark chamber will be the prime detection instrument. The instrumentation of SAS C will consist of modulation collimators, slot collimators, and proportional counters.

Opp, A. G.↗
NASA NTRS1967

Particles and fields

Interplanetary magnetic field, magnetosphere, solar energetic protons, and galactic cosmic rays

MAGNETOSPHERE↗