A SpaceX Dragon capsule, riding atop one of the company’s Falcon 9 rockets, carried the four Crew-10 astronauts — NASA’s Anne McClain and Nichole Ayers, Takuya Onishi of the Japan Aerospace Exploration Agency,

NASA astronauts Butch Wilmore and Suni Williams arrived at the ISS aboard Boeing's Starliner spacecraft last June. The duo were flying the capsule's first crewed flight test, which was expected to stay in orbit for about 10 days before flying the pair back to Earth.

The delayed mission must reach the space station before the two astronauts who've been "stuck" in space can return home.