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 .

The incident prompted the U.S. Federal Aviation Administration to ground the rocket but Falcon 9 was back in the swing of things in no time, launching another batch of Starlink satellites three days later. August’s landing mishap ended a streak of 267 successful touchdowns and booster recoveries since February 2021.

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.