Cos-B

Cos-B, short for Celestial Observation Satellite B, was the first mission by the European Space Research Organisation to study cosmic gamma ray sources. European scientists suggested it in the mid-1960s, and it was officially approved in 1969. The satellite carried special tools to detect gamma rays. NASA launched it for the ESRO on August 9, 1975.

The mission lasted until April 25, 1982. This was more than six and a half years, four years longer than expected. During its time, Cos-B gathered a lot of important information about gamma rays. It increased what we knew by 25 times. Scientists made a list called the 2CG Catalogue with about 25 gamma ray sources. They also created a map of our Milky Way galaxy. The satellite studied a special system of stars known as the X-ray binary Cygnus X-3.

Launch

COS-B was sent into space from Vandenberg Air Force Base on August 9, 1975, using a Delta 2913 rocket.