MBSAT A direct broadcast satellite for mobile users in Japan and Korea

The MBSAT spacecraft was launched on 13 March 2004 from Cape Canaveral Air Force Station on an Atlas III-A launch vehicle. The satellite is now in service at its orbital location of 144∘E longitude. The satellite is designed to provide high-quality audio, video and data services to mobile users in Japan and Korea. Broadcast transmissions use 25 MHz of bandwidth at the S-band frequency of 2.6 GHz, while uplinks and feeder links to terrestrial repeaters use the Ku-band. The MBSAT satellite design incorporates a large, unfurlable, mesh reflector for S-band broadcast. This 12 m (effective aperture) reflector coupled with phase-combined arrays of Traveling Wave Tube Amplifiers result in Effective Isotropic Radiated Power levels of 67-69 dBW over Japan and Korea coverage areas. The use of Stationary Plasma Thrusters for North-South stationkeeping significantly enhances the mission lifetime as well as minimizes potential disturbances to the 12 m reflector.