NASA reports 500-second RS-25 development-engine test
NASA reports that an RS-25 development engine completed a 500-second hot-fire test at Stennis Space Center on October 21.
What the record says
The October 23 account identifies engine No. 10001 and says the test reached a 111% power level. NASA says the data will help its engine-development work for the Space Launch System. This development engine will not fly.
Source details and supporting locations.
Practical next step
Read NASA’s account for the test’s scope and its role in engine development.
Limits and what is not established
A ground test is not a launch or proof that a particular mission is ready to fly.
Sources checked October 25, 2026. Later notices may change instructions or arrangements.