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The objectives of the OSO satellite series were to perform solar physics experiments above the atmosphere during a complete solar cycle and to map the entire celestial sphere for direction and intensity of UV light and X-ray and gamma radiation. The OSO 7 platform consisted of a sail section, which pointed two experiments continually toward the sun, and a wheel section, which spun about an axis perpendicular to the pointing direction of the sail and carried four experiments. Attitude adjustment was performed by gas jets and a magnetic torquing coil. A pointing control permitted the pointed experiments to scan the region of the solar disk in a 60- by 60-arc-min raster pattern. In addition, the pointed section could be commanded to select and scan any 7.5- by 5-arc-min region near the solar disk. Data were simultaneously recorded on tape and transmitted by PCM/PM telemetry. A command system provided for at least 155 ground-based commands. Only real-time data have been received since May 1973, when the second tape recorder failed. The spacecraft reentered the earth's atmosphere July 9, 1974.

Alternate Names

  • OSO-H
  • 05491

Facts in Brief

Launch Date: 1971-09-29
Launch Vehicle: Delta
Launch Site: Cape Canaveral, United States
Mass: 1400.0 kg

Funding Agency

  • NASA-Office of Space Science Applications (United States)


  • Astronomy
  • Solar Physics

Additional Information

Questions or comments about this spacecraft can be directed to: Dr. H. Kent Hills.



NameRoleOriginal AffiliationE-mail
Dr. Goetz K. OertelProgram ScientistNASA Headquarters 
Mr. Robert H. PickardProject ManagerNASA Goddard Space Flight Center 
Dr. Stephen P. MaranProject ScientistNASA Goddard Space Flight
Mr. Michael E. McDonaldProgram ManagerNASA Headquarters 
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