NASA targets March 18 for a critical engine test of its Space Launch System moon rocket

NASA's Space Launch System core booster for the Artemis 1 mission around the moon (seen in orange) stands atop the B-2 test stand at the Stennis Space Center in Mississippi for an upcoming engine test.
NASA's Space Launch System core booster for the Artemis 1 mission around the moon (seen in orange) stands atop the B-2 test stand at the Stennis Space Center in Mississippi for an upcoming engine test. (Image credit: NASA)

NASA's first Space Launch System megarocket will fire up its main engines in a critical test next week to prove it's ready for a trip to the moon later this year. 

The engine test, the final hurdle of NASA's extensive "green run" for the Space Launch System (SLS) core booster, is scheduled for March 18 at the agency's Stennis Space Center in Mississippi. If all goes well, the booster will then be shipped to NASA's Kennedy Space Center in Florida for the launch of Artemis 1, an uncrewed mission around the moon that is currently slated to fly in November. 

"This hot fire is the last test before the Artemis I core stage is shipped to the agency’s Kennedy Space Center for assembly and integration with the rest of the rocket’s major elements and the Orion spacecraft," NASA officials said in a statement on Wednesday (March 10). 

Video: How NASA's SLS megarocket engine test works

During the upcoming hot fire test, the SLS core booster will fire its four RS-25 rocket engines for up to eight minutes to simulate an actual Artemis launch of an Orion spacecraft. NASA first attempted the hot fire test on Jan. 16, but it shut down earlier than planned

NASA had hoped to perform a second hot fire test of the SLS booster in February, but ran into more delays due to valve concerns. SLS engineers spent recent weeks repairing and testing a liquid oxygen pre-valve on the rocket, setting the stage for the March 18 engine test. 

This week, SLS engineers were expected to power up the core booster for final systems check. On Tuesday (March 16), the rocket will be powered up for the actual hot fire, kicking off a two-day countdown for the engine test. 

NASA's SLS rocket is designed to be the go-to booster for the agency's Artemis program, which aims to launch astronauts back to the moon by 2024. It consists of a core booster, two strap-on solid rocket boosters and an upper stage to launch an Orion spacecraft toward the moon. 

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Elizabeth Howell
Staff Writer, Spaceflight

Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, "Why Am I Taller?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon: