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Thursday, October 22, 2026

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Space · Thursday, October 22, 2026

NASA test-fires an RS-25 engine for eight minutes

The File desk · Oct. 22, 2026, 6:40 a.m. ET

Confirmed1 primary sources

Status

Confirmed from NASA's account of a test on Wednesday, Oct. 21, 2026, at Stennis Space Center. The engine is a developmental article and will not fly. The photograph is NASA's.
  • Confirmed
    NASA said it fired RS-25 engine No. 10001 for 500 seconds on the Fred Haise Test Stand near Bay St. Louis, Mississippi.
  • Confirmed
    NASA said the developmental engine will not be used in flight.
A rocket engine firing on a test stand, with a bright exhaust plume.
NASA conducts a hot fire of RS-25 engine No. 10001 on the Fred Haise Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, on Oct. 21, 2026. Credit: NASA/Danny Nowlin. Source. Public domain. A work of the U.S. government, created by NASA.
NASA on Wednesday fired an RS-25 rocket engine for almost eight and a half minutes, the same burn the engines make when the Space Launch System leaves the pad. The test was at Stennis Space Center in Mississippi. The engine on the stand will not fly.1
NASA said that teams fired engine No. 10001 on the Fred Haise Test Stand, near Bay St. Louis, for 500 seconds, and up to 111 percent of the engine's rated power. The agency said the goals were to acceptance-test flight components and to validate a new thermal protection system. It said this developmental engine will not be used in flight. L3Harris Technologies is the prime contractor, the agency said.1
Four RS-25 engines produce up to 2 million pounds of combined thrust, NASA said. Wednesday's firing was one engine, on the ground.
Why it matters (Estimate). Estimate. The engines that lift astronauts on the next Moon rocket are proved, in part, by long burns on a stand in Mississippi before anyone is aboard. This engine stays on the ground. The parts and the heat shield it was testing are what NASA says it was checking.
The engine number on the stand was 10001.
How we know

Notes

  1. 1.NASA, “NASA Conducts RS-25 Engine Test in Support of Future Artemis Missions,” Oct. 21, 2026. https://www.nasa.gov/image-article/rs-25-engine-test-in-support-of-future-artemis-missions/ “NASA tested RS-25 engine No. 10001 on Oct. 21 on the Fred Haise Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi.” “almost eight-and-a-half minutes (500 seconds).” “up to the 111% power level.” “this developmental engine will not be used in flight.” Prime contractor L3Harris Technologies. “Four RS-25 engines produce up to 2 million pounds of combined thrust.” Photograph credit: NASA/Danny Nowlin. The image file is a U.S. government work.

What is still unknown or disputed

  • Which future flight will use the components that were tested. Not named in the article.
  • A precise start time for the burn, beyond the date. The article is dated Oct. 21.

Primary sources

Every claim in this story is drawn from the documents below. If a fetch failed, that is recorded on the card.

  1. Source 1

    RS-25 engine test for future Artemis missions

    NASA · October 21, 2026

    NASA fired RS-25 engine No. 10001 for 500 seconds at Stennis Space Center on Oct. 21, 2026. The developmental engine will not fly.

    https://www.nasa.gov/image-article/rs-25-engine-test-in-support-of-future-artemis-missions/

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