Pratt & Whitney Rocketdyne [UTX] Apr. 22 helped boost into orbit the U.S. military’s X-37B Orbital Test Vehicle.

“Pratt & Whitney Rocketdyne is pleased to provide power for the U.S. Air Force’s launch of its X-37B Orbital Test Vehicle,” said Jim Maus, director, expendable propulsion programs, Pratt & Whitney Rocketdyne. “This launch continues our proud history of supporting the U.S. military. “This third launch of the RL10 in 2010 is the 408th production model RL10 to fly, and we look forward to continuing our partnership with United Launch Alliance in this coming decade.”

The mission was launched from Cape Canaveral Air Force Station, Fla., by a United Launch Alliance Atlas V rocket.

The Atlas V is powered by the RD AMROSS RD-180 booster engine and a Pratt & Whitney Rocketdyne RL10 upper-stage engine. RD AMROSS LLC is a joint venture of Pratt & Whitney Rocketdyne and NPO Energomash.

“RD AMROSS and its partners — NPO Energomash and Pratt & Whitney Rocketdyne — congratulate the U.S. Air Force on this successful launch,” said Len Dest, president and CEO of RD AMROSS.

The Atlas V Centaur upper stage is powered by a single RL10A-4-2 engine that delivers 22,300 pounds of thrust.

For over 46 years, the RL10 has been one of the United States’ most reliable upper-stage engines. The Atlas V Common Core booster is powered by the RD-180 engine delivering nearly 1 million pounds of thrust. The RD-180 is the only liquid oxygen-kerosene fueled engine with an oxygen-rich staged combustion cycle flying in the United States today.