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- The Orbiting Geophysical Observatory (OGO 1) was successfully launched from Cape Kennedy on 5 September 1964 and placed into an initial orbit of 281 x 149,385 km at 31 degrees inclination. Two experiment booms failed to properly deploy, with one of the booms obscuring a horizon scanner's view of earth. As a result, the spacecraft attitude could not be earth oriented and OGO 1 remained spin stabilized at 5 rpm. Nevertheless, data from all 20 experiments on board was received, although at a "less than expected capacity" from some of them. During September 1964, acceptable data were received over 70% of the orbital path. Spacecraft operation was restricted to Spring and Fall due to power supply limitations. There were 11 such 3-month periods prior to the spacecraft being put into stand-by mode on 25 November 1969. OGO 1 was completely terminated on 1 November 1971. On board was the Positron Search and Gamma-Ray Spectrum experiment of Cline et al. It was designed to determine whether low-energy (0-3 MeV) positrons are trapped temporarily or permanently in the Van Allen regions and whether low-energy solar and interplanetary positrons exist at the edge of the Earth's magnetic field. A secondary objective was to detect gamma-ray bursts from the Sun in the energy range 80 keV - 1 MeV. The experiment consisted of 3 CsI crystals surrounded by a plastic anti-coincidence shield. The output of the whole unit was monitored by 3 PMTs. Once every 18.5 seconds, integral intensity measurements were made in each of 16 energy channels which were equally spaced over the .08-1 MeV range. The experiment did not achieve its goals due to electrical interference and secular degradation of the PMT responses. However, searching back through the data after the discovery of cosmic gamma-ray bursts by the Vela satellites revealed the detection of one or more such events in the OGO 1 data.
[Summary provided by NASA.]
Group: Platform_Details Entry_ID: OGO-1 Group: Platform_Identification Platform_Category: Earth Observation Satellites Platform_Series_or_Entity: OGO (Orbiting Geophysical Observatory) Short_Name: OGO-1 Long_Name: Orbiting Geophysical Observatory-1 End_Group Group: Synonymous_Platform_Names Short_Name: EOGO 1 Short_Name: OGO-A Short_Name: 00879 End_Group Group: Platform_Associated_Instruments Short_Name: SPECTROMETERS Short_Name: MAGNETOMETERS End_Group Group: Orbit Orbit_Inclination: 31.2 degrees Period: 3839.0 minutes Perigee: 281.0 km Apogee: 149385.0 km Orbit_Type: LEO > Low Earth Orbit > Polar Sun-Synchronous End_Group Creation_Date: 2007-02-12 Online_Resource: http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1964-054A Online_Resource: http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/ogo.html#ogo1 Sample_Image: http://heasarc.gsfc.nasa.gov/Images/ogo/ogo.gif Group: Platform_Logistics Launch_Date: 1964-09-05 Launch_Site: Cape Canaveral/Kennedy Space Center, USA Primary_Sponsor: NASA End_Group End_Group
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