NASA to Test-Fire Booster for Megarocket Tuesday: Watch Live

SLS Booster Test, March 2015
A solid rocket booster for NASA's Space Launch System rocket fires during a ground test in Utah in March 2015. (Image credit: NASA)

NASA will test-fire a booster for the world's most powerful rocket Tuesday morning (June 28), and you can watch the explosive action live online.

A solid rocket booster for NASA's Space Launch System (SLS) megarocket — which the agency is developing to blast astronauts toward Mars and other deep-space destinations — will fire for 2 minutes Tuesday at a facility in Utah, beginning at 10:05 a.m. EDT (1405 GMT). You can watch it live here at, courtesy of NASA TV; coverage starts at 9:30 a.m. EDT (1330 GMT).

NASA will hold a press conference at 11 a.m. EDT (1500 GMT) Tuesday to discuss the results of the test. You can listen to audio of the press conference here at as well, courtesy of NASA.

Tuesday's test will be the second and final ground test for the SLS booster before the huge rocket lifts off on its first space mission in 2018, which will be an uncrewed trip around the moon known as Exploration Mission-1 (EM-1).

The first ground test, which NASA declared a complete success, occurred in March 2015. The SLS booster burned as planned for 2 minutes — the same amount of time it will fire during a launch — and generated 3.6 million lbs. (1.6 million kilograms) of thrust, space agency officials said at the time.

When it's ready to go in 2018, the SLS will consist of a core stage powered by four RS-25 engines (the same kind that NASA used for the now-retired space shuttle), along with two 177-foot-tall (54 meters) solid rocket boosters like the one being tested Tuesday.

SLS is designed to launch NASA's Orion crew capsule, which is also in development. The duo is currently scheduled to fly astronauts for the first time in the early 2020s.

Tuesday's test, like the March 2015 trial, will take place in Promontory, Utah, at a facility owned by aerospace company Orbital ATK, an SLS partner.

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Mike Wall
Senior Space Writer

Michael Wall is a Senior Space Writer with and joined the team in 2010. He primarily covers exoplanets, spaceflight and military space, but has been known to dabble in the space art beat. His book about the search for alien life, "Out There," was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Michael on Twitter.