An Orbital Maneuvering System (OMS) engine firing on the Space Shuttle Challenger during mission STS-7. Visible in the open payload bay are parts of the Shuttle Pallet Satellite (SPAS), the protective cradles for the Palapa-B1 and Anik C2 communications satellites that were deployed during this mission, and the Remote Manipulator System (RMS), also known as Canadarm. The mission launched from Kennedy Space Centre on 18th June 1983 and landed at Edwards Air Force Base on 24 June.