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

The Crew-9 incident was the second Falcon 9 upper-stage issue to crop up in less than three months. On July 11, the rocket experienced a leak of liquid oxygen in its upper stage during the launch of 20 of SpaceX's Starlink internet satellites. As a result, the spacecraft were deployed too low and ended up being lost.

SpaceX is suspending launches of its Falcon 9 rocket after a problem with the deorbit burn of the upper stage on a crewed launch Sept. 28.