Boeing Starliner Orbital Demonstration Mission

[Yazata]

Industry gossip as of Monday Sept 6 is that the root cause of the 13 valves failing to move is still unknown.

Question is whether it was a single failure in the system that commands the valves (doesn't seem to be) or all 13 valves deciding to fail at once. That latter would suggest a fundamental defect in how the valves were designed. If that's the case, the valves will have to be removed, redesigned, tested and replaced, which will require partial disassembly of the vehicle. With nasa oversight reviews as well.

So while they were hoping for a OFT-2 launch before Thanksgiving, it's looking less and less likely they will launch this year.

Johnson Space Center in Houston has responsibility for scheduling missions to the Space Station. And they are said to be planning to replace planned Starliner crew rotation flights to the Station with SpaceX flights, for the first half of 2022 at least. I don't know if that's just contingency planning or whether they know something more.

But if the uncrewed OFT-2 doesn't get off until early next year and the crewed test flight several months after that, it certainly makes sense that operational Starliner flights won't be happening before next summer.

Speculation from engineers not involved with the investigation is that moisture might (or might not, it's speculation) have intruded into the valves which in the presence of cryo temperatures could have frozen them solid. That's a known problem, it's not supposed to happen and if it did it might require a redesign of the valves to better keep the moisture out.

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Boeing still studying Starliner valve issues, with no launch date in sight
https://arstechnica.com/science/2021/09/...ce-module/

INTRO: Nearly six weeks have passed since Boeing said it would de-stack its Starliner spacecraft from an Atlas V rocket and return the vehicle to its factory for "deeper-level" troubleshooting of problematic valves.

On Tuesday, NASA's chief of human spaceflight operations, Kathy Lueders, said teams of engineers and technicians from Boeing and NASA are continuing to assess the issue with sticky valves. "I think the team's making great progress on further troubleshooting," she said.

Just hours before launch, Boeing had to scrub the much-anticipated uncrewed test flight of the Starliner spacecraft in early August after 13 valves that control the flow of dinitrogen tetroxide oxidizer through the service module of the spacecraft malfunctioned. There are 24 oxidizer valves in the propulsion system, which is critical both for in-space travel as well as launch emergency escapes. During investigations on the launch pad, technicians were able to open some but not all of the valves.

Since returning Starliner to Boeing's Commercial Crew and Cargo Processing Facility in Florida, engineers have been able to gather data about the "dry" side of the valves, but they may need to remove the valves from the spacecraft to assess the "wet" side, Lueders said. This would be a cumbersome process.

Boeing and NASA will reach a decision point in the "next few weeks," she said, when they will decide whether to remove the valves from the service module for additional study. If this is the case, Boeing would likely pull forward a service module intended for a future crewed flight and use it for the uncrewed Orbital Flight Test-2 mission.

A new date for this OFT-2 mission has yet to be set, and Lueders indicated one may not be set any time soon. She suggested the mission probably will slip to 2022. "My gut is that it would probably be more likely to be next year, but we're still working through that timeline," she said... (MORE)

[Yazata]

Here's a new official status update on Starliner's OFT-2. It's starting to look like the investigation agrees with the engineers' speculation above, that the problem was indeed moisture in the valves.

They are trying to make it sound like it's not that big a deal and that worst-case it can be addressed by switching the service module. I'm not convinced, since if the second service module has more of the old-design valves, they would presumably be vulnerable to the same problem.

They telegraph the severity of the problem by suggesting that OFT-2 might not happen until next summer, which would be another year-long delay on top of the eariier software debacle. And to think that a couple of years ago I expected that Starliner would beat Crew Dragon to orbit. They were Boeing for God's sake!!

Commercial Crew is already reassigning astronauts that had been scheduled to fly Starliner to upcoming Crew Dragon flights, starting with Crew-5.

https://blogs.nasa.gov/kennedy/2021/10/0...-2-status/

Excerpts:

"Most items on the fault tree have been dispositioned by the team including causes related to avionics, flight software and wiring. Boeing has identified a most probable cause related to oxidizer and moisture interactions, and although some verification work remains underway, our confidence is high enough that we are commencing corrective and preventive actions...

Boeing has identified several paths forward depending on the outcome of the testing to ultimately resolve the issue and prevent it from happening on future flights. These options could range from minor refurbishment of the current service module components to using another service module already in production. Each option is dependent on data points the team expects to collect in the coming weeks...

Potential launch windows for OFT-2 continue to be assessed by nasa, Boeing, United Launch Alliance, and the Eastern Range. The team currently is working toward opportunities in the first half of 2022 pending hardware readiness, the rocket manifest, and space station availability."

[Yazata]

Starliner might be down but it isn't out. The long-delayed uncrewed OFT-2 (Orbital Flight Test 2) is on for May 19 at 6:54 PM EDT.

https://twitter.com/BoeingSpace/status/1...3926099988

https://starlinerupdates.com/

I really want to see Starliner succeed. It's easy to be snarky about Boeing, but many engineers have put years into this. I feel for them. And it's better for the United States to have another broomstick to put crew into orbit, rather than having all our eggs in the Crew Dragon basket (as successful as that's been.)

Boeing Space photo

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[Yazata]

OFT-2 is still on for tomorrow. They fueled the rocket today, then powered it down for the night. Very unlike SpaceX's "gas n' go" process where the rocket isn't fueled until right before launch, to prevent the supercooled fuel from warming up and expanding, thus allowing loading more fuel in the same tanks. (Convincing nasa that late fueling was safe took some doing.)

Countdown for OFT-2 resumes tomorrow morning towards a 6:54 PM EDT launch tomorrow afternoon.

Hope it goes well for Starliner and Boeing. America needs two successful dissimilar broomsticks in case one is grounded for some reason.

(ULA photo)

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Lots of heads will explode from being thunderstruck if it doesn't get off this time due to substantial technical problems. Shouts of conspiracy and sabotage, because such a prolonged level of incompetency could no longer be a satisfactory explanation.

[Yazata]

https://www.youtube-nocookie.com/embed/gy6iam6NjsU

https://www.youtube-nocookie.com/embed/_5KGePUTq_g

[Yazata]

Starliner is in orbit. Orbital injection burn appears to be nominal. It's already outperforming the first one since its onboard computer remembered what time it is and is performing its tasks in proper sequence. Still has to approach and dock with the Space Station tomorrow.

Edit - Just had a news conference that revealed a few small problems. A cooling unit wasn't cooling, but it finally kicked in and is now working fine.

And two of twelve larger thrusters they use for big orbit changes only worked for 20 seconds or so before quitting. The rest of the thrusters worked fine and lots of redundancy is built in. There is no threat to the mission. Smaller thrusters will be used to approach and dock with the station. But the big thrusters will be needed again for the deorbit burn.

As expected, the ULA Atlas performed flawlessly

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[Yazata]

Things are strangely quiet from Boeing Space. A go/no-go decision on whether to approach the Space Station should have happened about 20 minutes ago according to their mission schedule. Still no word on it.

Unclear what, if anything, it means. They may be running behind schedule, except that their schedule is more or less determined by where Starliner is in its orbit.

Things might be going great from their end but we just aren't hearing about it.

Or maybe they are frantically working a problem.

Arrival coverage starts 3:30 PM EDT and docking is supposed to happen around 7:10 EDT today. NASA's live-tream should be here

https://www.nasa.gov/nasalive

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Edit - It's being reported that NASA Houston just alerted the Space Station that Starliner is 'go' to proceed to rendezvous with the Station.

And Boeing Space just issued a confirming update

https://starlinerupdates.com/starliner-p...e-station/

It appears that as part of this decision process prior to approaching the Station, Starliner had to perform various maneuvering thruster tests, an abort maneuver demonstration, plus various sensor tests. It also had to undergo a docking system checkout. So I guess that satisfying NASA on all that is why they ran a little over.

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The NASA livestream reports that Starliner is currently about 54 miles from the Space Station, below and behind it.

[Yazata]

Starliner has arrived, successfully approached the Space Station and hard-docked with it. The hatch is open and the station astronauts are inside. Any astronauts riding uphill on Starliner would have arrived in fine shape.

(NASA photographs)

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