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Mission type Communication
Operator SES Americom (2008-2009)
SES World Skies (2009—2011)
SES S.A. (2011—)
COSPAR ID 2008-038B
Mission duration 16 years
Spacecraft properties
Bus STAR-2[1]
Manufacturer Thales Alenia Space
Launch mass 2,500 kilograms (5,500 lb)[1]
Start of mission
Launch date 14 August 2008, 20:44 (2008-08-14UTC20:44Z) UTC
Rocket Ariane 5ECA
Launch site Kourou ELA-3
Contractor Arianespace
Orbital parameters
Reference system Geocentric
Regime Geostationary
Longitude 125° West[2]
Period 24 hours

AMC-21, or Americom-21, is a communications satellite operated by SES S.A., formerly SES World Skies and SES Americom. It was launched in August 2008 and is expected to remain in service for approximately 15 years. It is currently located at 125° West longitude.

Spacecraft and mission design[edit]

AMC-21 is based on a STAR-2 platform that provides 4.4 kilowatts of power for the communications payload. The platform will support a 15-year on-orbit mission life.[3] It carries 24 J band (IEEE Ku band) transponders, which will be used to broadcast television signals to Canada the Caribbean, Mexico, and the United States.[2]

Manufacture and launch[edit]

Thales Alenia Space was the prime contractor for AMC-21, and provided the satellite's communications payload. The STAR-2 bus was subcontracted to Orbital Sciences Corporation, as were integration and testing of the satellite.[3] As prime contractor, Thales Alenia Space delivered the completed satellite to SES Americom.

AMC-21 was launched, along with the Superbird 7 satellite, by an Ariane 5ECA rocket on 14 August 2008.[4] The satellite separated from the carrier rocket in a geosynchronous transfer orbit. An onboard IHI-500N engine then raised it to an operational geosynchronous orbit and placed it at a longitude of 125° West of the Greenwich Meridian.[1] After successful completion of in-orbit testing, SES Americom took operational control of AMC-21 in September 2008.[5] In September 2009, SES Americom merged with SES New Skies to form SES World Skies, to which all of its operational satellites, including AMC-21, were transferred.

External links[edit]


  1. ^ a b c "AMC-21". Gunter's Space Page. 
  2. ^ a b "AMC-21". SES. 
  3. ^ a b "AMC-21". Orbital Sciences Corporation. 
  4. ^ "Another successful Arianespace launch: Superbird-7 and AMC-21 in orbit" (Press release). Arianespace. August 14, 2008. 
  5. ^ "Orbital Reports Third Quarter 2008 Financial Results" (Press release). Orbital. 16 October 2008.