The rocket meant to blast NASA’s Artemis 1 mission to the moon completed a final hot fire test at the Stennis Space Center in Mississippi on Thursday. Applause from the NASA control room afterward was a sign the agency might be able to put a launch date on the calendar soon.

Four engines fired for a total of eight minutes — the time it takes to travel 100 miles — while docked during the hot fire of NASA’s big new Space Launch System (SLS) rocket, the last stage in a comprehensive series of tests known as the Green Run. NASA’s scientists and engineers have a lot of data to look at, but everything appeared to work successfully.

Thursday’s test came about two months after the previous one, which was stopped early when the program hit intentionally conservative parameters. NASA said the engines fired as expected.

NASA streamed the hot fire live:

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The ambitious Artemis program aims to put people on the moon and build enough infrastructure there to help astronauts eventually travel to Mars. The first step of the Artemis 1 mission will be an uncrewed launch of the Orion spacecraft using the SLS. After disconnecting from the rocket core stage, Orion will orbit the moon for a month before returning to Earth.

If everything goes well, the next step would see astronauts aboard Orion making that same journey to the moon and back.

The most recent window given for the launch of Artemis 1 was November 2021, and with the success of the Green Run, NASA can soon schedule a more exact launch window, SpaceNews reported Wednesday.

The Green Run began in 2020 but the COVID-19 pandemic caused delays. When the exhaustive testing program was announced in 2019, NASA administrator Jim Bridenstine said the main reason for all the testing was astronaut safety. 

Thursday’s hot fire generated 2 million pounds of thrust, enough to send the more than 200-foot-tall core stage to the moon. The core stage weighs about 2.3 millions pounds, which includes 733,000 gallons of liquid hydrogen and liquid oxygen propellent.