The last in a series of eight modernized Global Positioning System Block IIR (GPS IIR-M) satellites built by Lockheed Martin [LMT] for the U.S. Air Force is set to launch aboard a Delta II rocket on Aug. 17 from Cape Canaveral Air Force Station, Fla. The spacecraft, designated GPS IIR-21(M), completes the IIR and IIR-M series of satellites the company designed and built for the Global Positioning Systems Wing, Space and Missile Systems Center, Los Angeles AFB, Calif. Modernized spacecraft deliver increased signal power to receivers on the ground, two new military signals to improve accuracy, enhanced encryption and anti-jamming capabilities for the military, and a second civil signal that will provide users with an open access signal on a different frequency.

“The team has once again completed a smooth and efficient launch readiness review and we are ready for flight,” said Col. Dave Madden, the Air Force GPS Wing Commander. “Through effective collaboration and a joint commitment to successful execution, the GPS IIR program has significantly improved our nation’s position, navigation and timing capabilities, and we look forward to enhancing the GPS constellation with this last IIR-M satellite.”

Lockheed Martin Space Systems and its navigation and payload provider ITT [ITT] designed and built 21 IIR satellites and subsequently modernized eight of those spacecraft.

GPS provides situational awareness and precision weapon guidance for the military. It is also an information resource supporting a wide range of civil, scientific and commercial functions, from air traffic control to the Internet. Air Force Space Command’s 2nd Space Operations Squadron, based at Schriever AFB, Colo., manages and operates the GPS constellation for both civil and military users.

The team is progressing on-schedule in the Critical Design Review (CDR) phase of the program and is on track to launch the first GPS IIIA satellite in 2014.