A NASA satellite launched in 1991 April to observe gamma rays from celestial objects. CGRO was the second of the series of Great Observatories. It was deorbited in 2000 June. The satellite carried four instruments covering the energy range 10 keV to 30 GeV. The BATSE (Burst and Transient Source Experiment) instrument studied gamma-ray bursts, while OSSE (Oriented Scintillation Spectrometer Experiment), Comptel (Imaging Compton Telescope), and EGRET (Energetic Gamma Ray Experiment Telescope) recorded images of the gamma-ray sky in the 0.1–10 MeV, 1–30 MeV, and 0.02–30 GeV ranges respectively. The satellite was named after the American physicist Arthur Holly Compton (1892–1962).

http://cossc.gsfc.nasa.gov/docs/cgro/ Official mission website.