The US Air Force will launch the first global positioning system block IIF satellite aboard a United Launch Alliance Delta IV vehicle on 20 May 2010.
The satellite is scheduled to be launched from Cape Canaveral Air Force Station, Florida.
It will be the first time a block IIF satellite has been launched on a Delta IV evolved expendable launch vehicle.
The GPS IIF system, critical to US national security, will add next-generation performance to the current satellite constellation.
It will sustain the GPS constellation and feature increased capability, improved mission performance and longevity.