The engine was fired for more than 8 minutes (500 seconds) on the A-1 Test Stand at Stennis Space Center near Bay St. Louis, the same amount of time RS-25 engines need to fire for launch of the SLS rocket.

The test series is designed to provide valuable data to Aerojet Rocketdyne, prime contractor for the SLS engines, as it begins production of new engines for use after the first four SLS flights. Four RS-25 engines, along with a pair of solid rocket boosters, will help power SLS at launch.

With testing of the engines for the rocket's first four Artemis program missions to the Moon already completed, operators now are focused on collecting data to demonstrate and verify various engine capabilities while reducing operational risk.

During the May 20 test, the team fired the engine at 111% of its original power level for a set duration of time, the same level that RS-25 engines are required to operate during launch. SLS is the most powerful rocket NASA has ever built and the only one capable of sending Orion, astronauts, and supplies to the Moon in a single mission.

As part of the Artemis program, NASA will land the first woman and the first person of color on the Moon and establish sustainable exploration in preparation for missions to Mars. SLS and NASA's Orion spacecraft, along with the commercial human landing system and the Gateway outpost in orbit around the Moon, are NASA's backbone for deep space exploration.

RS-25 tests at Stennis are conducted by a combined team of NASA, Aerojet Rocketdyne and Syncom Space Services operators. Syncom Space Services is the prime contractor for Stennis facilities and operations.