A Delta IV rocket, powered by Pratt & Whitney Rocketdyne-made RS-68 and RL10B-2 engines, boosted a third GPS satellite into orbit today from Cape Canaveral, company officials announced.

The Block IIF military navigation unit is the third in a planned series of 12 GPS satellites planned for launch. Officials say the new satellites will improve navigational accuracy for civil, commercial and defense use.

The RS-68 engine on the booster stage was built specifically for the Delta IV rocket, and was commercially financed by The Boeing Company, which owned Pratt & Whitney Rocketdyne until its 2005 sale to United Technologies.

The new GPS equipment features increased predicted signal accuracy, a 12-year lifespan and a military signal that is better designed to resist jamming in conflict areas.

Kelly Goff