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.
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.
"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.