NASA Efficiently Conducts Sizzling Hearth of RS-25 Engine That Will Energy the SLS (House Launch System) Rocket

Photograph credit score: Chris Russell
The current sizzling fireplace check of an RS-25 engine marked a giant step ahead for NASA’s Artemis program, and it went virtually unnoticed. On January 22, 2026, engineers at Stennis House Heart in Mississippi took out one of many RS-25 engines, quantity 2063, and examined it on the Fred Haise check stand. This included a 5-minute burn, and fortunately, the whole lot fell into place. The engine delivered 109% of its rated energy output, offering the rock-solid, strong efficiency required to position the House Launch System rocket into orbit with little fuss.

This engine has appreciable historical past, because it was initially deliberate for the SLS core stage of the Artemis II mission, the primary crewed flight that may transport 4 folks across the Moon and again. Nevertheless, final 12 months, a hydraulic leak appeared within the worst potential place: the first oxidiser valve actuator, which is chargeable for delivering propellant into the combustion chamber. Groups went via the processes of eradicating the engine, changing the defective element with a glowing new one, after which ready for the verification run. Earlier than being given the all-clear, a restored engine should exhibit its capabilities in a sizzling fireplace. So, now that this check went off with no hitch, quantity 2063 is able to embark on the SLS core stage for Artemis IV.

Each RS-25 engine chosen for an Artemis mission receives the identical remedy at Stennis, together with an intensive certification course of. NASA, L3Harris, and Sierra Lobo, the standard suspects, labored collectively to make this possible. Because the engine roared to life, huge clouds of vapour billowed into the Mississippi air, whereas the improved check platform stored the noise and drive beneath management.

Now think about 4 RS-25 engines clustered on the backside of the SLS core stage, every producing a big portion of the rocket’s general thrust, which totals greater than 8.8 million kilos. There are two stable rocket boosters on high of that, whereas the engines run on liquid hydrogen and liquid oxygen to provide pure exhaust, leaving solely water vapor. They had been initially designed for the house shuttle program, however they’ve since been modified and up to date to supply barely extra energy for SLS flights.

Every profitable milestone, equivalent to this one, brings the potential of Artemis II nearer to actuality, and this one is especially vital as a result of it is going to be the primary time people have ventured into deep house in fairly a while. They are going to be additional away from Earth than any human has been for the reason that Apollo period, and that is actual exploration terrain. Whereas the engines that may energy Artemis II have already been accredited and put in, testing like this preserve the pipeline working for future missions, which is crucial, particularly in relation to delivering folks to the Moon and in the end Mars. Artemis IV is a kind of future missions, and it’ll use this engine to assist put together for long-term lunar exploration and past.