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Short description: Saudi Arabian communications satellite
STS-51-G Arabsat 1-B deployment.jpg
Deployment of Arabsat-1B from STS-51-G
Mission typeCommunication
COSPAR ID1985-048C
Mission duration7 years
Spacecraft properties
BusSpacebus 100
Launch mass1,270 kilograms (2,800 lb)
Start of mission
Launch date17 June 1985, 11:33:00 (1985-06-17UTC11:33Z) UTC
RocketSpace Shuttle Discovery
STS-51-G / PAM-D
Launch siteKennedy LC-39A
Orbital parameters
Reference systemGeocentric
Longitude26° East
Period24 hours
Band2 E/F-band
25 G/H-Band

Arabsat-1B was a Saudi Arabian communications satellite which was operated by Arabsat. It was used to provide communication services to the Arab States. It was constructed by Aérospatiale, based on the Spacebus 100 satellite bus, and carried two NATO E/F-band (IEEE S band) and twenty five NATO G/H-Band (IEEE C band) transponders. At launch, it had a mass of 1,270 kilograms (2,800 lb), and an expected operational lifespan of seven years.[1]


Arabsat-1B was launched aboard Space Shuttle Discovery on mission STS-51-G. Discovery was launched from LC-39A at the Kennedy Space Center at 11:33:00 GMT on 17 June 1985.[2] It was deployed from Discovery, and boosted to a geosynchronous transfer orbit by means of a PAM-D upper stage. Sultan bin Salman bin Abdulaziz Al Saud flew aboard the Shuttle to supervise deployment, becoming the first Saudi citizen and first member of royalty to fly in space. Morelos 1 and Telstar 303 were also deployed on the same mission.

Arabsat 1B was placed into a geosynchronous orbit at a longitude of 26° East.[3] In October 1991, a problem developed with the spacecraft's attitude control system, causing it to drift eastward out of control.[4] The same fault had developed aboard its sister satellite, Arabsat-1A, a month earlier.[5] It failed completely in early 1992.[4]

See also

  • 1985 in spaceflight


  1. Krebs, Gunter. "Arabsat 1A, 1B, 1C / Insat 2DT". Gunter's Space Page. Retrieved 2009-07-05. 
  2. McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 2009-07-05. 
  3. Wade, Mark. "Arabsat". Encyclopedia Astronautica. Archived from the original on 2009-03-31. Retrieved 2009-07-05. 
  4. 4.0 4.1 "Arabsat 1B". TSE. Retrieved 2009-07-05. 
  5. "Arabsat 1A". TSE. Archived from the original on 2 June 2009. Retrieved 2009-07-05.