INSAT-1B was an Indian communications satellite which formed part of the Indian National Satellite System. Launched in 1983, it was operated in geostationary orbit at a longitude of 74 degrees east. At the end of its seven-year design life it was replaced by the newly launched INSAT-1D, dropping to backup status. In 1992, it was relocated to 93° east, before being decommissioned in August 1993.[3]
Built by Ford Aerospace and operated by the Indian National Satellite System,[3] INSAT-1B was based upon a custom satellite bus developed for the INSAT-1 series of satellites. It had a mass at launch of 1152 kg, and was expected to operate for seven years. The spacecraft carried twelve C and three S band transponders, powered by a single solar array.[3] A stabilisation boom was used to counterbalance radiation torques from the satellite's asymmetrical design.