SpaceX’s Falcon 9 rocket is grounded again after the vehicle’s second stage did not come down in the expected area of the ocean, following an otherwise successful mission that delivered a Dragon capsule and its crew to orbit. “We will resume launching once we better understand root cause,” the company said in a statement posted to X .

SpaceX successfully completed the first step on Sunday to rescue two astronauts stranded on the International Space Station, but it won’t bring the pair home for another five months.

The SpaceX Dragon, selected by NASA to transport astronauts Suni Williams and Butch Wilmore home, arrived Sunday at the International Space Station.

Two astronauts relinquished their seats on a four-person spacecraft so that their colleagues could return to Earth from the ISS, where they’ve been stuck since June.

Because NASA rotates space station crews approximately every six months, this newly launched flight with two empty seats reserved for Wilmore and Williams won’t return until late February. Officials said there wasn’t a way to bring them back earlier on SpaceX without interrupting other scheduled missions.

A SpaceX crew set to bring home two stranded astronauts arrived at the International Space Station on Sept. 29.

The SpaceX capsule will eventually bring home Butch Wilmore and Suni Williams, the NASA astronauts who piloted the Boeing Starliner test flight.

SpaceX has successfully delivered the Crew Dragon capsule that will rescue stranded NASA astronauts Suni Williams and Butch Wilmore. The pair recently watched as their ride, Boeing's issues-laden Starliner,