OGO-5
type: Concept
change note: 2022-03-11 15:18:42.0 [sritz] Move Concepts delete broader relation (null); add broader relation (OGO-5 [38eefa42-2943-43d6-9186-d797d089c9df,826135] - Orbiting Geophysical Observatory (OGO) [3e77610e-bb50-4c45-a62a-c50194ec16c2,826164]);
in scheme: platforms
definition: The fifth Orbiting Geophysical Observatory, OGO-5, was launched on 4 March 1968. The satellite, primarily devoted to Earth observation, was in a highly elliptical initial orbit with a 272 km perigee and an 148,228 km apogee. The orbital inclination was 31.1 degrees. The satellite took 3796 minutes to complete one orbit. Two experiments aboard OGO-5 produced cosmic high- energy results, although their intended target was the Sun. The spacecraft attitude control failed on 6 August 1971 and it was placed in a standby mode on 8 October 1971. Three experiments (none of which were related to cosmic high-energy detection) were reactivated from 1 June to 13 July 1972. Operation of OGO 5 terminated completely on 14 July 1972. The Anderson et al. (University of California, Berkeley) Energetic Radiations from Solar Flares experiment was operational from March 1968 - June 1971. Primarily devoted to solar observations, it detected at least 11 cosmic X-ray bursts in time coincidence with gamma-ray bursts seen by other instruments. The detector was a 0.5 cm thick NaI(Tl) crystal with a 9.5 sq-cm area. Data were accumulated into energy ranges of: 9.6-19.2, 19.2-32, 32-48, 48-64, 64-80, 80-104, 104-128, and > 128 keV. The data were sampled for 1. 15 seconds once every 2.3 seconds. The gamma-ray instrument on-board, sensitive to energies from 25-100 MeV, was a six gap spark chamber with an effective area of ~ 100 sq-cm. It was called the Energetic Photons in Primary Cosmic Rays experiment (Hutchinson et al., Southampton University). It had an angular resolution of ~ 30 degrees (FWHM). The satellite was Earth-pointing and passed regularly through the radiation belts, which led to severe restrictions on the sky regions which could be examined by the gamma-ray instrument. Other problems, such as an efficiency reduction in the anti-coincidence shield and data system difficulties, severely degraded the scientific return from the experiment. Data collection ceased altogether after 5 months…

Orbiting Geophysical Observatory (OGO)
type: Concept