SpaceX grounds its Falcon 9 rocket after a problem with its upper stage. Will the Crew-12 astronaut mission be affected?

SpaceX has temporarily grounded its workhorse Falcon 9 rocket, which is slated to launch four astronauts just eight days from now.

A Falcon 9 delivered 25 of SpaceX’s Starlink satellites into low Earth orbit (LEO) as planned on Monday (Feb. 2). But, after deploying the payloads, the rocket’s upper stage failed to perform its deorbit burn, which was designed to bring it down for controlled destruction in Earth’s atmosphere.

“Teams are reviewing data to determine root cause and corrective actions before returning to flight,” SpaceX said via X on Monday evening, in a post that announced the rocket’s grounding.

The Falcon 9 is the world’s busiest rocket by far. It launched a record-breaking 165 times in 2025 and already has 14 liftoffs until its belt this year.

The rocket is incredibly reliable, too. All of last year’s missions were successful, and just a single one — a Starlink launch on March 3 — experienced a significant anomaly. On that flight, a Falcon 9 first stage toppled shortly after landing on a ship at sea and was destroyed. (The booster did its job in the upward direction, and the 21 Starlink satellites were deployed into LEO as planned.)

SpaceX halted Falcon 9 launches for a week while it investigated that issue, which was traced to a fuel leak in one of the booster’s nine Merlin engines. This leak led to a fire shortly after touchdown, which weakened a landing leg and caused the vehicle to tip over.

It’s unclear how long this new launch hiatus will last. But both SpaceX and NASA doubtless hope the issue is resolved soon, for a very high-profile Falcon 9 launch is coming up — that of the Crew-12 astronaut mission to the International Space Station (ISS).

Crew-12 is currently scheduled to launch on Feb. 11 from Cape Canaveral Space Force Station in Florida. That’s four days earlier than originally planned: SpaceX and NASA fast-tracked Crew-12, because it will get the ISS back to its normal complement of seven crewmembers.

The orbiting lab has been staffed by a skeleton crew of three since Jan. 15, when the four astronauts of SpaceX’s Crew-11 left (a month earlier than planned) in the first-ever medical evacuation from the ISS.

NASA is keeping a close eye on the Falcon 9 investigation, which SpaceX is conducting along with the U.S. Federal Aviation Administration (FAA).

“We do have our teams with Commercial Crew embedded in that investigation,” NASA Associate Administrator Amit Kshatriya said on Tuesday, during a press conference that discussed Monday’s fueling test of the agency’s Artemis 2 moon rocket, which ended early due to a propellant leak.

“We’re pressing towards our Crew-12 window,” he added. “We’re planning towards, you know, just a week, a little bit more than a week from now, to start that preparation. But again, that’s going to be contingent on the return-to-flight rationale, [on] which we’re heavily partnered with both the FAA and SpaceX.”

And about that wayward Falcon 9 upper stage: Though it did not come back to Earth in a controlled fashion as planned on Monday, it did manage to “passivate” itself by venting propellant, according to SpaceX.

This maneuver lowered its perigee, or closest point to Earth, to 68.4 miles (110 kilometers), according to satellite tracker and astrophysicist Jonathan McDowell.

“It will reenter quickly,” McDowell said via X on Monday night.