Boeing Defense, Space & Security of El Segundo, Calif., will continue supporting deployment and testing of the GPS 2F navigation satellite constellation for the next five years under a $51 million U.S. Air Force contract awarded in late 2012.

The Boeing-built satellites provide more robust and jam-resistant signals than the earlier-generation GPS satellites. The newer satellites also have the operational L5 civil signal, which is used for commercial aviation as well as search and rescue operations.

Boeing is under contract for 12 GPS 2F satellites, three of which have already launched, according to a press release from the company. The next launch is scheduled for spring 2013. The GPS 2F satellites have 12-year design lives and will last longer than previous-generation spacecraft, according to the Air Force.

“The contract provides mission continuity for the Boeing GPS 2F fleet as we continue to deliver on our commitments,” Craig Cooning, vice president and general manager of Boeing Space & Intelligence Systems, said in the release. “With nine GPS 2Fs still awaiting deployment, the contract scope includes supplying all support needed until the Air Force calls for the vehicles.”

The work includes: prelaunch preparation, postlaunch checkout, handover and on-orbit support.