The COS-B satellite

COS-B was launched at 01:47 hours (GMT) on 9 August 1975 from Western Test Range, California, U.S.A. It was ESA's first satellite dedicated to a single experiment and was approved by the Scientific and Technical Committee in 1969, prior to the establishment of the European Space Agency.

Its scientific mission was to study in detail the sources of extra-terrestrial gamma radiation at energies above about 30 MeV.

The principal objectives were to study the spectrum and distribution of galactic gamma rays, investigate the flux and distribution of extragalactic gamma-ray emission, investigate some known point sources in the gamma-ray range and search for new point sources.