Boeing Starliner will not launch before Friday, May 10, and it may push into next week. The issue is a valve that controls liquid oxygen pressure on the upper stage of the rocket. It was humming/oscillating, and they need to examine it to see if it needs to be replaced.
If it doesn't, launch will be no earlier than Friday. If it does need to be replaced (which means the rocket needs to be rolled back), we're likely looking at launch dates into next week.
