Status
Success
Rocket
Mission Details
GPS IIF-6 (USA-251)
GPS IIF (Global Positioning System) or Navstar-IIF (Navigation System using Timing And Ranging) satellites are the fifth evolution of the second generation of GPS satellites. Improvements included an extended design life of 12 years, faster processors with more memory, and a new civil signal on a third frequency.
GPS-IIF satellites do not need to carry an apogee kick motor, in contrast to the earlier generations, as the launch vehicles provide direct insertion into the GPS orbit.
Boeing was contracted with options for up to 33 Block-IIF satellites in 1996, but in 2001 the contract was reduced to 12 Block-IIF satellites. The first Block-IIF satellite was originally scheduled to launch in 2006 but was finally launched in 2010, and the final IIF satellite was launched in 2016.