Sunday, May 18, 2008

GPS III Satellites

Earlier this week, Lockheed Martin announced that it had been awarded a $1.4 billion contract from the U.S. Air Force to build the next-generation system, known as GPS III. The goal is to deliver better accuracy and availability for both civilian and military users of the navigation technology (which, after all, was born as a military innovation).

In the first round of the undertaking, lead contractor Lockheed, along with ITT and General Dynamics, will build eight GPS IIIA satellites, the first of which is due to go into orbit in 2014. Later increments--for which no dates were specified--will see the construction and deployment of eight GPS IIIB and 16 GPS IIIC satellites, with progressively advanced capabilities.

One advance that Lockheed is promising: Eventually, all of the 32 satellites will be able to receive simultaneous updates from a single ground station through a cross-linked command and control architecture. The artificial constellation will also feature "a new spot beam capability for enhanced military (M-Code) coverage and increased resistance to hostile jamming."

The Air Force is set to launch its final two Lockheed-built GPS IIR satellites, one in June and the other in September. That will make for a total of 20 IIR satellites, which are more autonomous than earlier models, put into service over the span of around a decade. These last two are among eight IIR(M) models, which provide both M-Code and L2C (for civilian use) signals. The satellite launching in June also will transmit on a frequency called L5, intended primarily for aviation safety-of-life applications.

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