HS-376
The Boeing 376 is a communications satellite bus introduced in 1978 by Hughes Space and Communications Company. It was a spin-stabilized bus, a successor to Hughes HS-333.
Design
The satellite bus was designed and manufactured by Hughes. This spin-stabilized platform had two main sections. The spinning section was kept rotating at 50 rpm to maintain attitude, and a despun section was used by the payload to maintain radio coverage.The spinning section included the apogee kick motor, most of the attitude control, the power subsystem and the command and telemetry subsystems. The despun section contained the communications payload, including the antennas and transponders.
The stock version had a launch mass of, a mass of after reaching geostationary orbit and an 8 to 10-year design life. When stowed for launch, its dimensions were in height and in diameter. With its solar panels fully extended its height was.
Its power system generated approximately 1,100 to 1,200 watts of power at beginning of life, thanks to two cylindrical solar panels. The bottom panel was retracted around the body and top panel for launch, and extended downwards for operation. It also had two NiCd batteries for solar eclipses.