We'll have to wait a little longer to see SpaceX's next two astronaut missions take flight.
Elon Musk's company is gearing up to launch two crewed missions to the International Space Station: Ax-1, a private flight for Houston-based company Axiom Space, and Crew-4, a contracted mission for NASA.
Ax-1, the first-ever all-private crewed mission to the station, had been scheduled to lift off on March 30. However, Axiom announced today (March 18) that the launch has been pushed to April 3 at the earliest to "allow teams to complete final spacecraft processing ahead of the mission."
Photos: The first space tourists
And that change in turn delays Crew-4, which had been aiming to get off the ground on April 15.
"The current no-earlier-than launch date is Tuesday, April 19, pending completion of program reviews expected early next week to formalize the new target," NASA officials wrote in an update today.
The extra time will "allow appropriate spacing for operations and post-flight data reviews between human spaceflight missions and to allow for multiple consecutive launch attempts based on the orbital mechanics for arrival to the space station," they added.
Ax-1 will send four people to the space station for an eight-day stay. Three of them are paying customers, and the fourth is mission commander Michael López-Alegría, a former NASA astronaut who now works for Axiom.
Crew-4 will deliver NASA astronauts Kjell Lindgren, Bob Hines and Jessica Watkins and the European Space Agency's Samantha Cristoforetti to the orbiting lab. The quartet will spend months aboard the station conducting a range of science experiments.
Both Ax-1 and Crew-4 will employ SpaceX's Dragon capsule and Falcon 9 rocket. As its name suggests, Crew-4 will be the fourth full-fledged contracted astronaut mission that SpaceX carries out for NASA. (The astronauts of Crew-3 are still aboard the space station; they're expected to return to Earth next month.)
Ax-1 is the first of several crewed space station missions that Axiom plans to fly with SpaceX over the next few years. But it won't be SpaceX's first all-private astronaut mission; that distinction goes to Inspiration4, which sent four passengers on a free-flying, three-day mission to Earth orbit last September.
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.