STS-37 Payload Gamma Ray Observatory Pad-B in PCRThe primary objective of the STS-37 mission was to deploy the Gamma Ray Observatory. The mission was launched at 9:22:44 am on April 5, 1991, onboard the space shuttle Atlantis. This videotape shows the Gamma Ray Observatory being placed in the payload bay of the shuttle. The Payload Changeout Room (PCR) and the clean room operations required to place the payload in the bay are shown.