HS-393

Boeing 393
ManufacturerBoeing Satellite Development Center
Country of originUnited States
ApplicationsCommunications satellite
Specifications
Spacecraft typeSpin-stabilized
Launch mass2.2 to 2.5 t (2.4 to 2.8 tons)
DimensionsDiameter: 3.7 m (12 ft)
Height (stowed): 3.4 m (11 ft)
Height (deployed): 10 m (33 ft)
Power2 to 2.2 kWatts
Batteries2 × 38Ah NiH2 batteries
RegimeGeostationary orbit
Design life8 years
Production
StatusRetired
On order3
Built3
Launched3
Retired3
Maiden launchJCSAT-1 March 6, 1989
Last launchSBS 6, October 12, 1990
Related spacecraft
Derived fromHS-376
← HS-376 Boeing 601 →

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.[1][2]

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.[1][3] With its solar panels fully extended its height was 10 m (33 ft).[4][5]

Its power system generated approximately 2,350 watts of power at beginning of life and 2,200 at end of life, thanks to two cylindrical solar panels. These panels used K7 and K4-3/4 solar cells, with more than twice the number of cells than on the HS-376.[1] The bottom panel was retracted around the body and top panel for launch, and extended downwards for operation.[1] It also had two 38 Ah NiH2 batteries.[4]

Its propulsion system was composed of two R-4D liquid apogee engines 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.[1] It included enough propellant for orbit circularization and 8 years of operation.[4]

Its payload was composed of a 2.4 m (7 ft 10 in) antenna that fed Ku band transponders.[1][3]

Satellites

The HS-393 was a more powerful platform than the HS-376, being able to supply 2,200 kW of power versus the 1,400 kW of the HS-376HP. Only three were ever built.[2]

Satellite Other Names Operator Model Ordered Launch Launch Vehicle Launch Result Mass at launch (kg) Mass at BOL (kg) Remarks
JCSAT-1 JSAT Corporation HS-393 1985 1989-03-06 Ariane 44LP Success 2,280 kg (5,030 lb) 1,346 kg (2,967 lb) First Japanese commercial satellite.[4][1]
JCSAT-2 JSAT Corporation HS-393 1985 1990-01-01 Commercial Titan III Success 2,280 kg (5,030 lb) 1,346 kg (2,967 lb) [4][1]
SBS 6 Satellite Business Systems HS-393 1985 1990-10-12 Ariane 44L Success 2,478 kg (5,463 lb) 1,500 kg (3,300 lb) Launched alongside Galaxy 6.[5][3]

See also

References

  1. ^ a b c d e f g h "JCSAT 1,2". Boeing Satellite Development Center. Archived from the original on 2010-02-07. Retrieved 2016-08-17.
  2. ^ a b Krebs, Gunter Dirk (2016-04-21). "Hughes: HS-393". Gunter's Space Page. Retrieved 2016-08-17.
  3. ^ a b c "SBS 6". Boeing Satellite Development Center. Archived from the original on 2010-02-07. Retrieved 2016-08-17.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  4. ^ a b c d e Krebs, Gunter Dirk (2016-08-17). "JCSat 1, 2". Gunter's Space Page. Retrieved 2016-07-20.
  5. ^ a b Krebs, Gunter Dirk (2016-08-17). "SBS 6". Gunter's Space Page. Retrieved 2016-07-20.