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 .

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.

SpaceX launched the rescue mission on Saturday with two seats reserved for Butch Wilmore and Suni Williams, who will return to Earth in 2025.

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.

NASA engineers are running checks to solve the mystery of why the Falcon 9's engine failed to perform a routine maneuver to lower the rocket's altitude.

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

SpaceX's two-person Crew-9 mission is scheduled to arrive at the International Space Station today (Sept. 29), and you can watch the action live.