Update for 2:20 a.m. EDT on April 21: Crew-4 will now launch no earlier than April 26, because of delays in the departure of the private Ax-1 astronaut mission from the ISS. Read our story here.
The rocket that will launch SpaceX's next astronaut mission just got a test run.
That mission, called Crew-4, is scheduled to lift off atop a Falcon 9 rocket from Kennedy Space Center (KSC) in Florida on Saturday morning (April 23). It will send four astronauts to the International Space Station (ISS) for NASA aboard a SpaceX Dragon capsule.
To help prepare for the moment, SpaceX performed a "static fire" test of the Falcon 9 today (April 20), briefly igniting the rocket's first-stage engines while holding the vehicle down at KSC's Pad 39A, the company announced via Twitter.
Related: SpaceX's new Crew-4 Dragon capsule gets a name: Freedom
It wasn't the first time those engines have fired; this particular first stage has flown three times before, including on SpaceX's Crew-3 mission, which delivered four astronauts to the ISS in November 2021. Those spaceflyers are still aboard the orbiting lab, but they'll come back down to Earth shortly after Crew-4 arrives.
Like their rocket, the Crew-4 astronauts — NASA's Kjell Lindgren, Robert Hines and Jessica Watkins and the European Space Agency's Samantha Cristoforetti — have been gearing up for liftoff.
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"Crew-4 astronauts, SpaceX, and @NASA completed a full rehearsal of launch-day activities," SpaceX representatives said via Twitter today, in a post that included a photo of the crewmembers inside their Dragon, a new vehicle that they named Freedom.
Crew-4 astronauts, SpaceX, and @NASA completed a full rehearsal of launch day activities pic.twitter.com/b6AtNdJMxTApril 20, 2022
As its name suggests, Crew-4 is the fourth contracted crewed mission that SpaceX will fly to the ISS for NASA. But it will be the company's seventh astronaut mission overall; SpaceX has also flown a demonstration mission to the orbiting lab in 2020 and two private crewed missions, one of which, called Ax-1, is ongoing.
Ax-1 sent four private astronauts to the space station on April 9, and they're due to depart for Earth as soon as the weather will allow a safe splashdown of their Dragon capsule off the Florida coast.
Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or on Facebook.
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Michael Wall is a Senior Space Writer with Space.com 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.