Today's historic launch of Starliner has been scrubbed.
An automatic hold triggered by the ground launch sequencer, or the computer that launches the rocket, stopped the countdown clock at 3 minutes and 50 seconds ahead of launch.
The cause of the automatic hold is not clear, but mission teams estimate a 24-hour turnaround time, according to the NASA broadcast.
Now, teams will prepare to safely extract the crew from the capsule.