The Cos-B Experiment and Mission

The Cos-B gamma ray detector, orbit, operations and data processing, calibration and in-flight performance, and observation program are described. The Cos-B satellite carries a single spark-chamber experiment capable of detecting gamma rays with energies greater than 30 MeV. The mission objectives are to study the spatial, energy, and time characteristics of high energy radiation of galactic and extragalactic origin. Correlation of X-ray and gamma ray variations is obtained by the inclusion in the payload of a proportional counter sensitive to X-rays of 2 to 12 keV. The satellite was launched in Aug. 1975 into an eccentric polar orbit, chosen to optimize the observability of interesting regions of the sky and the recovery of data.