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OTS 2 (Orbital Test Satellite 2) was an experimental satellite inherited by ESA in 1975 from its predecessor, the European Space Research Organization (ESRO). The first of the pair of OTS satellites was lost at launch in September 1977. OTS 2 became one the the first GEO communications satellites to carry six Ku-band (14/11 GHz) transponders and was capable of handling 7,200 telephone circuits. With a mass of approximately 445 kg on station, the OTS 2 bus was hexagonal with overall dimensions of 2.4 m by 2.1 m. Two solar panels with a span of 9.3 m provided 0.6 kW of electrical power. British Aerospace was the prime contractor from the European MESH consortium which developed the OTS vehicle. It completed its primary mission in 1984 after which the spacecraft was involved in a 6-year program of experiments, including the testing of a new attitude control technique taking advantage of solar wind forces. In January 1991, OTS 2 was moved out of the geostationary ring and into a graveyard orbit.

Alternate Names

  • 10855
  • OTS2

Facts in Brief

Launch Date: 1978-05-11
Launch Vehicle: Delta
Launch Site: Cape Canaveral, United States
Mass: 865 kg

Funding Agencies

  • Unknown (United States)
  • European Space Agency (International)


  • Communications
  • Engineering

Additional Information

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

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