NASA conducted a second RS-25 single engine hot fire test on April 6, 2021, as part of a new series to support the development and production of engines for the agency’s Space Launch System (SLS) rocket on future missions to the Moon.
The full-duration hot fire of more than eight minutes (500 seconds) was conducted on the A-1 Test Stand at NASA’s Stennis Space Center near Bay St. Louis. It is part of a scheduled seven-test series designed to provide valuable data for Aerojet Rocketdyne, lead contractor for the SLS engines, as it begins production of new RS-25 engines for use after the first four SLS flights.
Four RS-25 engines help power SLS at launch, firing simultaneously to generate a combined 1.6 million pounds of thrust at launch and 2 million pounds of thrust during ascent. The RS-25 engines for the first four SLS flights are upgraded space shuttle main engines and have completed certification testing.
During the new test series, operators will focus on evaluating new engine components and reducing risk in engine operation. They will fire the engine through a range of operating conditions to demonstrate and verify its capabilities and to provide data to enhance production of new engines being manufactured with cutting-edge and cost-saving technologies.
The initial test of the new series was conducted on January 28 for 500 seconds as well, the same amount of time the engines must fire during a launch to power the SLS rocket to orbit. During the subsequent full-duration hot fire on April 6, operators also gimbaled the RS-25 engine, using a new NASA-designed vector control system for the first time since it was installed. “Gimbaling” refers to how the engine must move on a tight circular axis in order to ensure proper flight trajectory.
NASA is building SLS as the world’s most powerful rocket. SLS will fly to the Moon as part of NASA’s Artemis program, including the Artemis I uncrewed test flight this year that will pave the way for future flights with astronauts to explore the lunar surface and prepare for missions to Mars. 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.