
GPS IIR
As the prime contractor for the GPS IIR program, Lockheed Martin Space Systems, Newtown, Pa., designed and built 21 IIR spacecraft for the Global Positioning Systems Wing, Space and Missile Systems Center, Los Angeles Air Force Base, Calif. The final eight spacecraft, designated Block IIR-M, were modernized to enhance operations and navigation signal performance. The current fleet of Block IIR and IIR-M satellites within the overall GPS constellation has reached over 100 cumulative operational years on-orbit. The U.S. Air Force's next-generation GPS spacecraft, known as GPS III, is being built by a Lockheed Martin-led team that includes industry partners ITT of Clifton, N.J. and General Dynamics of Gilbert, Ariz.
The GPS III team is progressing through the Critical Design Review (CDR) phase of the program and is scheduled to complete the overall space vehicle CDR in mid-August, two months ahead of schedule. This milestone will validate the detailed GPS III design to ensure it meets warfighter and civil requirements, and allow the program to begin the production phase. The first GPS IIIA satellite is projected to launch in 2014. GPS III will improve position, navigation and timing services and provide advanced anti-jam capabilities yielding superior system security, accuracy and reliability. The next generation GPS IIIA satellites will deliver significant improvements over current GPS space vehicles, including a new international civil signal (L1C) and increased M-Code anti-jam power with full earth coverage for military users.

