Air Force launches third GPS Block IIF satellite

The Air Force successfully launched the third Global Positioning System IIF satellite on Oct. 4 from Cape Canaveral, Fla., aboard a United Launch Alliance Delta IV-Medium rocket, the service said.

The GPS Block IIF spacecraft furnish accurate positioning, navigation and timing services to military and civilian users  worldwide. Boeing builds the GPS Block IIF satellite for the Air Force, which operates them once they are in space.

The GPS IIF is an interim class of GPS satellite. The purpose of the Block IIF is to keep Navstar GPS operational until the next-generation, Lockheed Martin-built GPS Block IIIA satellites become operational. The first GPS Block IIIA satellite is scheduled for launch in 2014.

The first GPS IIF satellite, Space Vehicle 1, was launched by a Delta IV rocket on May 28, 2010, and the second one on July 16, 2011, also from Cape Canaveral Air Force Station.