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Navstar 55



NAVSTAR 55, also known as USA 178, and as GPS 2R-12, is an American navigational satellite in the GPS fleet that was launched from Cape Canaveral by a Delta 2 rocket at 22:54 UT on 23 June 2004. The 2.1 tonne satellite will soon be manuevered into Slot 4 in Plane F to replace the aging GPS 2A-16 that was launched in November 1992. (GPS 2A-16 will however be repositioned in the same Plane as a backup, till its failue. Links to GPS fleet is available in section C-2 below.

Alternate Names

  • 28361
  • GPS 2R-12
  • Navstar55
  • USA 178

Facts in Brief

Launch Date: 2004-06-23
Launch Vehicle: Delta II
Launch Site: Cape Canaveral, United States

Funding Agency

  • Unknown (United States)


  • Navigation/Global Positioning

Additional Information

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

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