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GPS 2R-M Satellite

The Lockheed Martin-built GPS 2R-M1 spacecraft was supposed to launch from Cape Canaveral in May 2002 aboard a Boeing Delta 2 rocket, but issues involving internal components have put the brakes on the $75 million mission. Problems included:

• A mis-installed capacitor on a navigation payload under assembly.
• Screws were discovered not properly torqued in a navigation payload. Inspections performed on GPS 2R-M1 showed its screws were torqued.
• Navigation payload-manufacturer ITT determined that a Destructive Physical Analysis had not been performed for a relay used on the GPS 2R-M1 satellite’s L-Band transmitter DC-DC converter.

The Air Force and Lockheed Martin believe the issues have been resolved, permitting GPS 2R-M1 to resume its launch campaign. A firm date has not been set, but Air force officials expect a June launch.

GPS satellites send continuous navigation signals that allow users virtually anywhere on the planet to find their position in latitude, longitude and altitude and determine time. The triangulated signals are so accurate that time can be figured to less than a millionth of a second, velocity to within a fraction of a mile per hour and location to within a matter of feet.

The military’s orbiting GPS constellation began to take shape in 1989, and features 24 primary and several backup satellites flying into six orbital groupings 11,000 miles above Earth. To replace the original satellites as they age, Lockheed Martin built 21 so-called “replenishment” satellites. Dubbed the “2R” series, 12 satellites of this current generation have been deployed since 1997 (the first one was lost in a launch explosion).

The Air Force continues to launch new satellites as replacements to keep the critical navigation system in good health. Twenty-nine satellites are currently in orbit.

Now, the remaining 8 are being given the designation GPS 2R-M (modernized), and retrofitted with upgrades to provide additional capabilities. The updated craft increases the power for existing Global Positioning System signals and offers two new military signals, as well as a second civilian signal to benefit users around the world. The military signal advancements will provide warfighters with a more robust jam-resistant signal and enable better targeting of GPS-guided weapons in hostile environments, while the new civilian signal will remove ionospheric errors and improve accuracy.

If all goes well, the GPS 2R-M2 satellite could lift off in October or November, with the next following behind in December 2005 – February 2006.

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