J-2X engine No. 10002 was tested June 13 on the A-1 Test Stand at NASA’s Stennis Space Center in south Mississippi. The 60-second test signaled the start of a series of firings to collect critical data on engine performance. By the time the J-2X tests conclude later this summer, the engine will have been fired at full power and for the total time it would operate during an actual flight, while being gimbaled in the same way it must move during flight.