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 .

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.

SpaceX has risen to prominence on the strength of its Falcon 9 rocket, a launch vehicle that, until recently, seemed almost bulletproof. The Falcon 9 has now suffered its third launch anomaly in as many months, leading SpaceX to once again ground the rocket until engineers can understand why this weekend's launch didn't go entirely as planned.