NASA Tests Critical In-Flight Capability During RS-25 Hot Fire

NASA conducted a long-duration hot fire of an RS-25 engine April 26, demonstrating a critical capability needed to stabilize a rocket during an actual launch and flight to space. Operators at the Fred Haise Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, fired an RS-25 certification engine for 12 minutes (720 seconds), which is longer than the 500 seconds the engines must fire to help launch the Space Launch System rocket to space and the longest-duration test of the current certification series. In addition, operators demonstrated the gimbaling, or pivoting, capability of the engine. Gimbaling is the technique of moving (swiveling) the engine a few degrees along a tight circular or back-and-forth axis to direct engine thrust and “steer” the rocket on a proper trajectory. The April 26 hot fire marked the sixth in a 12-test series designed to certify production of new RS-25 engines for future Artemis missions by lead contractor Aerojet Rocketdyne. Four RS-25 engines fire simultaneously, producing up to 2 million pounds of combined thrust, to help power each SLS launch.