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Boeing's Starliner


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https://www.reuters.com/business/aerospace-defense/exclusive-boeing-clashes-with-key-supplier-ahead-starliner-spacecraft-launch-2022-05-11/

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Boeing in a statement provided by a spokesperson to Reuters acknowledged for the first time that it ultimately intends to redesign Starliner's valve system to prevent a repeat of the issue that forced last year's test-flight postponement. The Boeing statement said that "we are working on short- and long-term design changes to the valves."

 

Quote

Boeing officials privately regard Aerojet's explanation for the faulty valves as a bid to deflect responsibility for the costly delay for Starliner and to avoid paying for a redesigned valve system, two of the sources said.

"It's laughable," one person involved in the joint Boeing-NASA investigation of the value issue said of Aerojet's claim, speaking anonymously to discuss confidential supplier relations. "Getting a valve maker or propulsion system provider to write down, 'Yeah, I screwed that up' ... that's never gonna happen."

 

 

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10 minutes ago, Kerwood Floyd said:

That thing is cursed!

The problem is in its name.

There is already Starlink, and they are trying Starliner.

The Pauli principle is resisting.

They should return the original, good nerdish name - CST-100.

P.S.
Of course, in this case there is chance it follows "The 100" series.

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3 hours ago, Beccab said:

Something even worse came out from this news:

 

It's insane he's still ALIVE, how is it possible to have almost killed a person in a parachute test?

The Angry Astronaut is gonna be bursting at the seams :valjoy:

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8 hours ago, tater said:

IIRC, SpaceX had a similar problem, right? Only, their problem happened sooner so they were able to fix it sooner?

ISTR that they had a problem with nitric acid eating up check valves on the Dragon, and they eventually redesigned the system to use one-time blowout panels that completely isolated the valves from the oxidizer unless they needed to do an emergency LES event.

Or am I misremembering that?

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1 hour ago, mikegarrison said:

IIRC, SpaceX had a similar problem, right? Only, their problem happened sooner so they were able to fix it sooner?

That might be right. Maybe they fired the contractor, and built their own?

 

Regardless, seems like Boeing might be doing that, dumping the AJR parts and coming up with their own solution.

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2 minutes ago, tater said:

That might be right. Maybe they fired the contractor, and built their own?

 

Regardless, seems like Boeing might be doing that, dumping the AJR parts and coming up with their own solution.

I wasn't talking about contractors, I just meant that this stuff is hell on valves. I assume this is the kind of learning experience that everyone is going to have to go through with something conceptually brand new (reuseable spacecraft capsules).

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Posted (edited)
4 minutes ago, mikegarrison said:

I wasn't talking about contractors, I just meant that this stuff is hell on valves. I assume this is the kind of learning experience that everyone is going to have to go through with something conceptually brand new (reuseable spacecraft capsules).

Yes. Does Starliner share hypergols between RCS, OMS, and the abort system? Seems like a case that has not happened before (before CST-100, AND Crew Dragon). Plus, saves mass—if you use the abort, you don't need the OMS/RCS, you're heading home anyway. Minus—valve issues, complexity, failure modes. Both vehicles share that.

Edited by tater
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9 hours ago, sevenperforce said:

I must confess I did not realize that Centaur placed Starliner in a properly suborbital trajectory.

Yeah, I did not know that, either.

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Posted (edited)
On 5/11/2022 at 6:48 PM, tater said:

Yes. Does Starliner share hypergols between RCS, OMS, and the abort system? Seems like a case that has not happened before (before CST-100, AND Crew Dragon). Plus, saves mass—if you use the abort, you don't need the OMS/RCS, you're heading home anyway. Minus—valve issues, complexity, failure modes. Both vehicles share that.

Well, Starliner has twelve monopropellant RCS engines on the capsule which are separate from the twenty OMS engines, twenty-eight RCS engines, and four abort engines on the service module. The abort engines and OMS engines are definitely plumbed to the same bipropellant tanks; I'm assuming the service module RCS engines are also plumbed to the same bipropellant tanks but I suppose there is a chance they could be monopropellant. The RCS engines on the capsule don't fire until re-entry.

Orion is the same way -- twelve monopropellant thrusters on the capsule for re-entry only; all orbital maneuvering and attitude is handled by the service module.

Crew Dragon of course has a fully-integrated bipropellant OMS/RCS for the entire vehicle, plumbed to the same propellant reserves used for the abort engines.

Using abort propellant for OMS is a very good idea on paper; the only thing you "lose" in a nominal mission is the weight of the abort engines themselves. But obviously it does add complexity.

Presumably the Orion/Starliner approach is technically safer because there are no bipropellants inside the capsule itself, only in the service modules. Although I suspect that if the Starliner's service module bipropellant tanks did the same RUD that happened to Crew Dragon in April 2019, the Starliner capsule itself wouldn't have faired any better.

Edited by sevenperforce
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Spoiler
6 minutes ago, sevenperforce said:

Starliner has twelve monopropellant RCS engines on the capsule which are separate from the twenty OMS engines, twenty-eight RCS engines, and four abort engines on the service module.

6gc3xb.jpg

 

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4 minutes ago, tater said:

NASA coverage is live a little less than 1 hour before launch:

 

90% go on weather.

Call off at last minute on account of forgetting the mystery goo unit?

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1 minute ago, Minmus Taster said:

Call off at last minute on account of forgetting the mystery goo unit?

Let's hope they checked staging.

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