L3Harris Continues Manufacturing SLS Core Stage Engines Despite Artemis Program Uncertainty

Article: L3Harris Pushes Forward with Manufacture of SLS Core Stage Engines Despite Uncertain Future for Artemis Program While the future of NASA’s Artemis program remains uncertain, with the possibility of the Space Launch System (SLS) rocket being phased out in President Trump’s proposed NASA budget for fiscal year 2026, Melbourne-based L3Harris is pushing forward with the manufacture of the powerful rocket’s core stage engines. The SLS core stage is powered by four RS-25 engines, which for the first four Artemis missions are engines from the Space Shuttle Program refurbished by Aerojet Rocketdyne, which L3Harris acquired in 2023. The first engine produced for the fifth mission, built from scratch after the depletion of the space shuttle supply, is now in NASA’s hands. On Friday, the engine, dubbed No. 20001, underwent an 8 1/2-minute hot fire on a test stand at NASA’s Stennis Space Center in Mississippi. The duration of the hot fire test equals the time the engine would burn on launch if and when Artemis V gets off the ground. The engine was also cranked up to 111% power. “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,” said Kristin Houston, president of the company’s space propulsion and power systems division. So far, NASA has flown the SLS once on the Artemis I mission in 2022. The four RS-25 engines powered the core stage that paired with two solid rocket boosters from Northrop Grumman, combined to create 8.8 million pounds of thrust on liftoff. It remains the most powerful rocket ever to make it to orbit. While SpaceX’s Starship and Super Heavy nearly doubles that thrust, it has only performed suborbital test launches so far. Artemis II, the first crewed flight of the Orion spacecraft, is set to launch atop SLS on its second flight no later than April 2026 on a mission to fly around, but not land on, the moon. A lunar landing mission is supposed to come with Artemis III, slated to fly by summer 2027, but it still needs a working version of Starship to act as the human landing system. While the future of Artemis may shift, L3Harris will continue to build engines for which it has contracts. Manufacturing of the RS-25s happens in California and is 30% less expensive than those produced and refurbished for the shuttle program using updated processes such as 3D printing. A test version of the new engine design went through a 12-step certification series completed last year to pave the way for operational engine production. NASA has already ordered up to 24 of the new engines on top of the 16 refurbished shuttle-era engines that would support flights through the ninth Artemis. The order totals $3.5 billion, which is about $145 million per engine. Each engine will get tested at NASA’s Stennis before it gets sent to the Michoud Assembly Facility in New Orleans where the core stage is manufactured by Boeing. Starting with Artemis III, the core stage parts will be shipped to Kennedy Space Center for final assembly.