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Sirius 2



Sirius 2 was a Swedish communications satellite launched from the Kourou Space Complex in French Guiana aboard an Ariane 44L rocket. It was placed in a geosynchronus orbit at 4.9 deg E. It carried 32 Ku-band transponders powered by 44-watt traveling-wave tube amplifiers (TWTAs). The spacecraft used gallium arsenide solar cells to generate a minimum of 1400 watts of power at end of life and relied on nickel-hydrogen batteries for power through eclipses. Its antenna had shaped surface octagonal reflectors of approximately 2 m in diameter, with single offset feeds. This antenna had three surfaces: one for horizonatally polarized signals, one for vertically polarized signals, and one for on-station tracking and command.

Sirius 2 was used primarily for direct-to-home and cable television services as well as data distribution in Scandinavia and neighboring countries, but it was also capable of providing television distribution and high-speed internet data to Greenland. The Ku-band effective isotropic radiated power (EIRP) was minimum 54 dBW in the primary zone.

The spacecraft was moved to 31.5 deg E longitude in April 2008 in order to expand services to Central and Eastern Europe. It suffered an apparent sudden technical anomaly in January 2009 that ended its in-service lifetime. It was to be moved into a graveyard orbit.

Alternate Names

  • 25050
  • Astra 5A
  • Sirius2

Facts in Brief

Launch Date: 1997-11-12
Launch Vehicle: Ariane 44L
Launch Site: Kourou, French Guiana
Mass: 815 kg
Nominal Power: 1400 W

Funding Agency

  • SES (Sweden)


  • Communications

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office

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