First of 24 New RS-25 Engines Ready For Testing at NASA Stennis

Teams at NASA’s Stennis Space Center have successfully lifted RS-25 engine No. E20001 onto the Fred Haise Test Stand, marking a major milestone in the production of new engines that will power the Space Launch System (SLS) rocket.

The E20001 engine is the first of 24 new production RS-25 engines built under NASA’s contract with L3Harris Technologies (formerly Aerojet Rocketdyne). This series of engines will support Artemis deep-space missions, beginning with Artemis V, and will fire during launch to propel the SLS and the Orion spacecraft into orbit.

A New Era of RS-25 Testing Begins

The engine was transported to the Fred Haise Test Stand on an engine transport trailer before being carefully lifted onto the west side deck and maneuvered into position.

The next steps will involve securing the RS-25 into the thrust frame adapter, which is essential for gathering critical performance data. This adapter simulates launch conditions, ensuring the engine is tested under real-flight stress levels.

Soon, the team at NASA Stennis will use an engine vertical installer to raise and secure the RS-25 into its final test configuration. Once locked in place, the engine will undergo extensive pre-test checkouts before the highly anticipated 500-second hot fire test scheduled for next month.

A 500-Second Hot Fire Test Ahead

The full-duration hot fire test will last 500 seconds, replicating the engine’s operational performance during an actual SLS launch. During deep-space missions, RS-25 engines fire for about eight minutes, reaching up to 111% power levelto provide the necessary thrust to propel the SLS rocket into orbit.

This upcoming test is crucial for verifying the performance, reliability, and efficiency of the new RS-25 production engines. The data collected will inform engine calibration and optimization, ensuring they meet the rigorous demands of Artemis missions.

During the last RS-25 test campaign, a series of 12 engine tests were conducted including multiple 500 second hot fires.

Advancing the Artemis Program

The RS-25 engine is a legacy propulsion system, originally developed for the Space Shuttle Program and upgraded for NASA’s Artemis program.

The next-generation engines feature modernized components, including 3D-printed parts, which improve manufacturing efficiency and reduce costs while maintaining high performance.

With the Artemis program aiming to return humans to the Moon and establish a sustainable presence, the RS-25 engines play a critical role in NASA’s exploration goals. The power and reliability of these engines will enable deep-space missions and pave the way for future crewed missions to Mars.

With RS-25 E20001 now secured on the Fred Haise Test Stand, engineers will begin final preparations for the hot fire test. If successful, the data will validate the engine’s readiness for integration into future SLS missions.

The Artemis V mission, set to be one of the first to use these new production engines, will continue NASA’s journey toward sustained lunar exploration and prepare for the next great leap—sending astronauts to Mars.