NASA conducted its third RS-25 engine test on Nov. 29, a key part of a 12-test series to certify the engine in the SLS rocket for use on the Artemis mission. Demonstrating the key capabilities required for SLS (Space Launch System) rockets to fly during the Artemis lunar mission.

These tests involve advanced manufacturing processes such as 3D printing and are designed to ensure reliability and performance for future missions to the moon and Mars. Engines are tested under extreme conditions and exceed specified operating limits to ensure safety and effectiveness.

Aerojet Rocketdyne, a subsidiary of L3Harris Technologies, is the primary engine contractor for the SLS rocket and is applying new manufacturing technologies and processes, such as 3D printing, to the production of the new RS-25 engine.

On the Fred Haise Test Stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi, workers gimbaled the RS-25 engine around a center point during a nearly 11-minute (650-second) heat. Gimbal technology is used to control and stabilize the SLS as it enters orbit.

During the Nov. 29 test, operators also pushed the engines beyond any parameters they might encounter during flight to ensure safe operations. The 650-second test exceeds the 500 seconds the RS-25 engines must run to help the SLS reach space. The RS-25 engine's ignition power also reached 113%, exceeding the 111% required to put the SLS into orbit.

The third RS-25 engine test on November 29 advanced NASA’s goal of certifying an engine using a new manufacturing process for deep space missions. Image source: NASADannyNowlin

The ongoing series of tests will continue into 2024 as NASA continues its mission to return humans to the lunar surface to establish the long-term presence of scientific discoveries and prepare for human missions to Mars.

Four RS-25 engines fire simultaneously, producing 1.6 million pounds of thrust at launch and 2 million pounds of thrust during ascent to power each SLS flight. NASA and Aerojet Rocketdyne modified 16 surviving space shuttle main engines, all of which were flight-proven at NASA's Stennis Space Launch Complex for Artemis missions I through IV.

Each of the new RS-25 engines that will power the SLS will also be tested at NASA Stennis. RS-25 testing at the base was conducted by a joint team of NASA, Aerojet Rocketdyne and SyncomSpace Services operators. SyncomSpaceServices is the prime contractor for Stennis facilities and operations.