Latest USAF GPS Satellite In Orbit

The U.S. Air Force's latest Global Positioning System (GPS) satellite was delivered to orbit this morning by a United Launch Alliance Delta II from Cape Canaveral, Fla.

Liftoff took place at 4:34 a.m. EDT from Launch Complex 17A. One hour and eight minutes later, the rocket deployed GPS IIR-20, the seventh of eight modernized spacecraft in the GPS Block IIR-M series built by Lockheed Martin.

GPS IIR-20 includes a modernized antenna panel that will boost signal power to ground receivers, two new military signals, enhanced encryption and anti-jamming, and a second civil signal that will provide users with an open access signal on a different frequency. The spacecraft also includes a new demonstration payload that will transmit a third civil signal located on the L5 frequency (1176.45MHz).

The flight marked the 47th launch for the GPS position, navigation and timing system. The Delta II 7925-9.5 rocket featured a Pratt & Whitney Rocketdyne RS-27A main engine and nine strap-on solid rocket motors provided by Alliant Techsystems (ATK). An Aerojet AJ10-118K engine powered the second stage, while an ATK-built spin-stabilized Star-48B solid-rocket motor powered the third.

ULA's next flight will orbit the second Air Force Wideband Global Satcom (WGS) satellite. A launch attempt last week was scrubbed due to a fuel leak, and the Atlas V rocket had to be rolled back to its integration facility for checks. The team hopes to reschedule the flight for next week, according to ULA spokesman Mike Rein.

Photo: Ben Cooper