NASA and L3Harris Successfully Test New RS-25 Rocket Engine for Artemis

STENNIS SPACE CENTER, MS - On June 25, 2025, NASA and L3Harris Technologies successfully conducted a hot-fire test of the new RS-25 rocket engine, which is slated to power the fifth launch of the Space Launch System (SLS) rocket as part of the Artemis lunar exploration program. This significant test marks the first hot-fire of a flight version of the RS-25 engine, demonstrating advancements in propulsion technology critical for future space missions.

The RS-25 engine, originally developed for the Space Shuttle program, has undergone extensive modifications to increase its efficiency and reduce production costs. During the 500-second acceptance test, the new engine achieved a throttle up to 111%, exceeding the performance requirements of its predecessors. This test was pivotal in confirming that the upgraded engine meets NASA's stringent performance and reliability standards.

'We are thrilled with the results of this test,' stated Kristin Houston, President of Space Propulsion and Power Systems at Aerojet Rocketdyne, a subsidiary of L3Harris. 'This successful acceptance test shows that we've been able to replicate the RS-25's performance and reliability while incorporating modern manufacturing techniques and upgraded components such as the main combustion chamber, nozzle, and pogo accumulator assembly.'

NASA awarded L3Harris a contract in 2015 to restart the design and production of the RS-25 engines, utilizing contemporary manufacturing techniques including 3D printing. The new engines are projected to be approximately 30% less expensive than the original shuttle engines, while maintaining the same level of reliability and efficiency necessary for deep space missions.

The Artemis program aims to establish a sustainable human presence on the Moon by the end of the decade, with the ultimate goal of preparing for future Mars missions. According to NASA Administrator Bill Nelson, 'This engine is a crucial component in our efforts to return humans to the lunar surface and is vital to maintaining America's leadership in space exploration.'

The successful testing of the RS-25 engine not only signifies a technological advancement but also emphasizes the United States' commitment to leading in lunar exploration and ensuring a strategic presence in space. L3Harris, classified as a Trusted Disruptor in the defense industry, is integral to providing the necessary technology solutions that connect various domains including space, air, land, sea, and cyber.

As the Artemis program progresses, the development and testing of the RS-25 engine serve as a foundation for future launches. The implications of this successful test extend beyond just the technical aspects; it symbolizes a renewed focus on international space exploration and the competitive nature of space technology among nations.

Looking ahead, continued advancements in rocket propulsion and engineering will be essential as NASA aims to conduct its next Artemis mission, which is expected to include a crewed lunar landing by 2026. The upcoming tests and launches will further refine the capabilities of the RS-25 engine and ensure its readiness for the challenges of deep space exploration.