NASA ignited RS-25 engine No. 10001 on Oct. 21 at the Fred Haise Test Stand in Stennis Space Center, Mississippi. The engine burned for 500 seconds, matching the burn time of RS-25 engines during Space Launch System liftoff. Engineers also operated the engine at 111% power, reaching thrust levels required for new production engines that will carry the SLS rocket and Orion spacecraft into orbit. The test served as an acceptance check of flight components destined for future Artemis missions and evaluated a new thermal protection system designed to shield the engine nozzle from launch‑induced heat. Although this particular engine will not fly, the hot‑fire data will help NASA and its prime contractor L3Harris Technologies refine performance and reliability. Each SLS launch draws about 2 million pounds of combined thrust from four RS-25 engines. All RS-25 engines undergo testing at Stennis before flight, with the work carried out by NASA personnel alongside L3Harris and Nova Space Solutions operators.