Pratt & Whitney Rocketdyne, a United Technologies Corp. company, was awarded a $1.2-billion NASA contract to design, develop and test a J-2X engine that will power the upper stages of the Ares I and Ares V launch vehicles.

Building on the experience and legacy of the ApolloSaturn Program, the J2X is powered by liquid oxygen and liquid hydrogen and will provide 294,000 pounds of thrust to power the Ares vehicles.

The J2X incorporates significant upgrades to meet the higher performance and reliability requirements for the Ares vehicles. The contract award includes ground and test flight engines and extends through Dec. 31, 2012.

"The J2X builds on our knowledge and experience with the proven J-2 and J-2S engines, while simultaneously integrating stateofthe-art technology in order to give NASA a powerful, cost-effective, reliable engine," said Jim Maser, Rocketdyne president.