800px-CGRO s37-96-010

NASA's Compton Gamma Ray Observatory drifts away from the space shuttle Atlantis on April 7, 1991, following its deployment during the STS-37 mission.

The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with energies from 20 keV to 30 GeV, in Earth orbit from 1991 to 2000. It featured four main telescopes in one spacecraft, covering X-rays and gamma rays, including various specialized sub-instruments and detectors. Following 14 years of effort, the observatory was launched from Space Shuttle Atlantis during STS-37 on April 5, 1991, and operated until its deorbit on June 4, 2000.[1] It was deployed in low earth orbit at 450 km (280 mi) to avoid the Van Allen radiation belt. It was the heaviest astrophysical payload ever flown at that time at 17,000 kilograms (37,000 lb).


  1. "Gamma-Ray Astronomy in the Compton Era: The Instruments". Gamma-Ray Astronomy in the Compton Era. NASA/ GSFC. Retrieved 2007-12-07.