The Compton Gamma-Ray Observatory was launched on
April 5, 1991. The second of NASA's great observatories, CGRO has four
instruments that cover an unprecedented six orders of magnitude
in energy, from 30 keV to 30 GeV. Over this energy range CGRO has an
improved sensitivity over previous missions of a full order of
magnitude. It operated for almost 9 years and the mission ended
on June 4 2000. Unlikely most satellites, CGRO was too large to
burn up entirely in the atmosphere during re-entry.
To ensure safety on the Earth's surface, NASA redirected the
spacecraft into Earth's atmosphere with a controlled re-entry.
Mission Characteristics
Lifetime : 5 April 1991 - 4 June 2000
Energy Range : 30 keV - 30 GeV
Special Features : First Great Gamma-Ray observatory
Payload :
The Burst and Transient Source Experiment (BATSE)
an all sky monitor 20-1000 keV
The Oriented Scintillation Spectrometer Experiment (OSSE)
0.05-10 MeV energy range
The Compton Telescope (Comptel)
0.8-30 MeV capable of imaging 1 steradian
Energetic Gamma Ray Experiment Telescope (EGRET)
30 MeV-10 GeV
Science Hightlight:
The Discovery of an isotropic distribution of the Gamma-ray burst events
Mapping the Milky Way using the 26 Al Gamma-ray line
Discovery of Blazar Active Galactic Nuclei as primary source of the
highest energy cosmic Gamma-rays