Country of origin United States Design life 8 years Derived from HS-376 | Spacecraft type Spin-stabilized Launch date 6 March 1989 | |
Applications Communications satellite Launch mass 2.2 to 2.5 t (2.4 to 2.8 tons) Dimensions Diameter: 3.7 m (12 ft)
Height (stowed): 3.4 m (11 ft)
Height (deployed): 10 m (33 ft) Manufacturers Boeing Satellite Development Center, Hughes Aircraft Company Similar Intelsat 1R, Magellan, Astra 1G, Intelsat 35e, Intelsat 9 | ||
The Hughes 393 (sometimes referred to as the HS-393 is a communications satellite bus introduced in 1985 by Hughes Space and Communications Company. It was a spin-stabilized bus that had twice as much power as the HS-376 platform.
Contents
Design
The satellite bus was designed and manufactured by Hughes. It had a launch mass of 2.2 to 2.5 t (2.4 to 2.8 tons), a mass of 1.35 to 1.5 t (1.49 to 1.65 tons) after reaching geostationary orbit and an 8-year design life. When stowed for launch, its dimensions were 3.4 m (11 ft) in height and 3.7 m (12 ft) in diameter. With its solar panels fully extended its height was 10 m (33 ft).
Its power system generated approximately 2,350 Watts of power at BOL and 2,200 at end of life, thanks to two cylindrical solar panels. These panels used K7 and K4-3/4 solar cells and were more than twice the number than on the HS-376 The bottom panel was retracted around the body and top panel for launch, and extended downwards for operation. It also had a two 38Ah NiH2 batteries.
Its propulsion system was composed of two R-4D LAE with a thrust of 490 N (110 lbf). It also had two axial and four radial 22 N (4.9 lbf) bipropellant thrusters for station keeping and attitude control. It included enough propellant for orbit circularization and 8 years of operation.
Its payload was composed of a 2.4 m (7 ft 10 in) antenna fed Ku band transponders.
Satellites
The HS-393 was a powerful platform than the HS-376 platform, being able to supply 2,200kW of power versus 1,400 of the HS-376HP. But only three were ever built.