| Manufacturer | Boeing Satellite Development Center | ||
|---|---|---|---|
| Country of origin | United States | ||
| Applications | Communications satellite | ||
| Specifications | |||
| Spacecraft type | Spin-stabilized | ||
| Design life | 8 years | ||
| 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) |
||
| Power | 2 to 2.2 kWatts | ||
| Batteries | 2 × 38Ah NiH2 batteries | ||
| Regime | Geostationary orbit | ||
| Production | |||
| Status | Retired | ||
| Built | 3 | ||
| On order | 3 | ||
| Launched | 3 | ||
| Retired | 3 | ||
| First launch | JCSAT-1 March 6, 1989 | ||
| Last launch | SBS 6, October 12, 1990 | ||
| Related spacecraft | |||
| Derived from | HS-376 | ||
|
|||
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.
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 These panels used K7 and K4-3/4 solar cells and were more than twice the number than on the HS-376 The bottom panel was retracted around the body and top panel for launch, and extended downwards for operation.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.