RS-68A completes test series

STENNIS SPACE CENTER, Miss. - Pratt & Whitney Rocketdyne successfully completed a series of hot-fire tests on the certified RS-68A engine, the world's most powerful hydrogen-fueled engine, at NASA's John C. Stennis Space Center, Miss. The tests demonstrated the capability of the engine to operate for 4,800 seconds of cumulative run time, four times the design life of the engine and more than 10 times what's needed to boost a United Launch Alliance heavy-lift rocket into space. The RS-68A, which evolved from the RS-68, is a liquid-hydrogen/liquid-oxygen booster engine designed for the Delta IV family of launch vehicles. In addition, Pratt & Whitney Rocketdyne and NASA has begun testing on the upper-stage J-2X engine. To date, five hot-fire tests have been conducted on the J-2X, which could be used to boost humans beyond low-Earth orbit. (Source: Pratt & Whitney via PRNewswire, 09/22/11)