J-2X tested seven seconds

STENNIS SPACE CENTER, Miss. -- A Rocketdyne J-2X had a seven-second test firing Wednesday that focused on a modified nozzle extension that dissipates heat generated by the engine. The test was on the A-2 stand at the NASA center in South Mississippi. The Pratt and Whitney Rocketdyne J-2X is being developed for use in the second stage of NASA's Space Launch System. Another J-2X test, this one a powerpack, is expected next week. The powerpack sits on top of the engine and feeds the thrust chamber system, which produces engine thrust. (Source: GCAC, photo release, 05/16/12)