BSAT-1a was a geostationary communications satellite designed and manufactured by Hughes (now Boeing) on the HS-376 platform.
It was originally ordered and operated by the Broadcasting Satellite System Corporation (B-SAT).
It was used as the main satellite to broadcast television channels for NHK and WOWOW over Japan.
The despun section contained the communications payload, including the antennas and transponders.
[10] Its payload was composed of a four active plus four spares Ku band transponders fed by a TWTA with an output power of 106 Watts.