Some updates from Tory Bruno and NASA:

https://x.com/torybruno/status/1797322732360663540

Ground system Launch Sequencer Repair is complete (replacement of power chassis). Retesting nearly complete. Engineering Review Board just finished up. Good to go pending successful finishing of the retesting.

https://x.com/NASA/status/1798154905099845881

We’re hours away from launching a new spacecraft for the first time! Liftoff of #Starliner Crew Flight Test is targeted for 10:52am ET (1452 UTC).

Liftoff!

Stage separation and Centaur ignition.

NASA webcast ended. Starliner docking to the ISS scheduled for 2024-06-06, 16:15 UTC.

SRB burnout and jettison.

Go no-go poll is complete. Teams are go for launch.

Updates on the management of the (previously known) helium leak:

https://x.com/cbs_spacenews/status/1798502162957218178

A5/Starliner CFT: Flight controllers have told the Starliner crew they are isolating the spacecraft’s port helium manifold, the one known to have a small but persistent leak. Mission control to the crew: “No action on the caution message. To catch you back up, we’re taking a look at the port helium manifold, we just isolated it to characterize this leak rate.”

https://x.com/cbs_spacenews/status/1798502491018957035

A5/Starliner CFT: NASA commentator: “The team here on the ground keeping an eye on the port side of the spacecraft, particularly the manifold valves, noticing some helium increasing (sic) coming out of that valve, so the team is going to step through procedures to close that valve.”

https://x.com/cbs_spacenews/status/1798504654738743305

A5/Starliner CFT: These exchanges came down about an hour ago; mission control just now told the crew they’re still assessing; no indication yet on whether this is a real concern or simply precautionary; managers said before launch leak would have to dramatically increase to be any sort of worry and for what it’s worth, commander Butch Wilmore doesn’t sound at all concerned; the crew is about to turn in for the night after a busy first day in space

Additional helium leaks have been identified:

https://x.com/cbs_spacenews/status/1798528269416911143

A5/Starliner CFT: Apologies for the delay updating; as it turns out, flight controllers have detected two additional helium leaks, one in “top” manifold 1 and the other in “port” manifold 1; that’s in additional to the small leak in port manifold 2 that was known before launch; top manifold 1 and port manifold 1 have been isolated, taking 6 reaction control jets off line; port manifold 2 remains open

https://x.com/cbs_spacenews/status/1798528951163207846

A5/Starliner CFT: Wilmore and Williams have gone to bed; flight controllers promised them a detailed update and presumably a manifold management plan when they get up tomorrow at 4:30am EDT (0830 UTC) to press into the space station rendezvous; it’s not yet known what sort of impact, if any, the leaks might have on downstream maneuvers, but mission managers said before launch they had developed a variety of backup plans to manage the helium supply through the de-orbit thruster firing at the end of the mission. Stay tuned

https://x.com/cbs_spacenews/status/1798535593732739452

A5/Starliner CFT: One word of caution; we did not hear any actual leak rates specified other than an initial comment that the leak they knew about before launch, the one in port manifold 2, was roughly the same as it was before takeoff. The additional leakage could be minor or more significant. We won’t speculate because we don’t yet have any data to base it on.

https://x.com/NASASpaceflight/status/1798520862884180095

Starliner CFT Update:

Butch and Suni have now begun the sleep portion of the timeline just after Mission Control hand-off to the overnight team.

While the crew rests, Mission Control will be working the problem of the helium leaks that were detected in the Top Helium 1 and Port Helium 1 manifolds. Those are separate from the Port Helium 2 manifold leak seen before launch.

Before the crew went to bed, the ground had them close those two helium manifold valves and reconfigure the propulsion system to maintain attitude control while teams work the problem.

No burns are scheduled for the next eight hours which allows time for the crew to sleep without alarms - NSF’s Philip Sloss.

Nominal orbital insertion burn.

“Nominal MECO on Starliner.”

Starliner separation from Centaur confirmed.

Upcoming orbital insertion burn at ~T+31 minutes.