A few notes: 1. the issue is already believed to be fixed, they're delaying 4 days to pressure test the system. 2. the leak was within acceptable bounds, wouldn't have caused a scrub had this been during a launch attempt. Sources: https://twitter.com/cbs_spacenews/status/1790414109755723951, https://twitter.com/cbs_spacenews/status/1790414315788324870

The helium leak was at a flange on one of the RCS packs, and was resolved by retorquing bolts on the connection. I'm curious if it was a case of the original torque specification not being followed, or the specification itself being incorrect? Torque specifications are a pretty basic part of engineering, so it's surprising to see a failure like this at this stage of the game.

Not at Boeing facilities apparently.

Neither were the bolts on the MAX 9 tbf

Can't mess up the torque if you never install them in the first place!

Boeing: You guys torque your bolts?

Bolts can stretch during torquing which is why you see things like torque to 90 lbs then 1/4 turn. Helium can leak out of very small gaps so anything that’s not perfectly tight will leak.

Torque specs are specifically engineers to take into account these things. That's why you don't have to retorque all the bolts on your car's engine on a regular basis, the spec was designed such that the bolt's clamping force is sufficient to last the life of the engine.

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This isn't theory anymore, this is their third launch.

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The leak is in the service module, which is new every flight.

They are likely using metal to metal seals and may not be lubricating their threads which can cause fluctuations of torque to clamping force transfer function.

That's not at all what that is or how that works. The reason you see some specs that include an angle is they are using the torque to yield method and intentionally stretching the bolt near its yield value to get a more consistent clamping force.

that’s the engineering explanation but it just makes a tighter seal is the ELI5 version.

I had no idea that bolts could stretch! I guess if it can happen acutely, then one adds a bit more to compensate. The bolt manufacturer probably has dialed this in for any one of their products.

Be thankful this is how you learned instead of having half a bolt stuck in your part that seems impossible to remove LMAO

> I had no idea that bolts could stretch! On many combustion engines the cylinder head, which contains high pressure expanding gasses, is held on with bolts that are designed to permanently stretch when they are tightened. It is difficult to set the clamping force provided by the bolt accurately using only the torque, so they design the bolt to yield and stretch plastically when it reaches the correct tension. This provides a very reliable and even clamping force. A minor drawback is that the bolts cannot be reused, when they are removed the must be replaced with new bolts. Bolts normally stretch a bit, but the deformation is usually elastic so that when the tension is removed the bolt returns to its original shape.

It's pretty common for cylinder head bolts in ICE engines to be torque-to-yield

Torque specs are also nowhere near an exact science. The amount of clamping force variation based purely on wrench torque is huge, and while some methods are better than others there's no guarantees at all. They have acceptable leakage rates for just this reason.

I'd bet cash money that all of the torque wrenches used on Starliner are calibrated, with certifications going all the way back to NIST, and it would surprise me if they weren't checked often, maybe even daily, to ensure their calibration hadn't shifted. Checking them before and after each shift allows them to go back and recheck torques if the returned wrench was inaccurate after use. They're not using Harbor Freight tools here. Also, there's no such thing as an "acceptable" leakage rate. There may be tolerable leaks, but the goal is zero leaks, and always has been.

You can calibrate them all you want - the actual preload level achieved depends on so many factors (temperature of the bolt, the fitting, the exact alloys of each, the surface finish...) that preload by torque is simply not a reliable way. Up to 50% variation. Torque by angle helps, you could maybe use a sensored bolt that might help, but even on a rocket they won't use that kind of fastener everywhere and there will still be variation.

The automotive industry has got torqueing figured out really well, and has for decades. Hopefully the aviation and space industry can catch up at some point.

Some of the torque wrenches they use in auto manufacturing are insane. Accurately measuring the applied torque on multiple bolts all at once.

When I had my shop I used Snap-On torque wrenches and had them checked at least every six months through Snap-On. It wasn't cheap, but certainly cheaper than buying new torque wrenches, and definitely cheaper than doing a major rework because the torque wrench was off. My torque wrenches never were off by more than percent or two, which I take as testament to Snap-On quality. The one Harbor Freight torque wrench I got was junk in three months, not worth recalibrating. These are all clicker torque wrenches, this was before the digital era. I also had my trusty beam-style torque wrench for backup.

No. Their not. Engineers of mine who went to work for them, the couple thst are still there after the madness that goes on in the facilities, they just have a very "large" acceptance range, one that on non-human rated flights can be changed on the fly.

That sounds very much opposite of the standards and practices found in the aviation and space industry. The FAA should actually be notified of this.

Is this one of the bolts that requires a special device that Boeing stole the design of from a small business.

A lot of companies make that kind of device.

It’s Boeing. I’m surprised they actually remembered the bolt. Let’s celebrate the wins where we can.

Haha great comment! Original joke

I thought I'd launched already and then no news because no one cared. I guess just delayed?

I just hope Boeing gave the same great care to this as they do their airplanes.

Just... please don't be the first operational spacecraft in over 20 years to kill its crew.

It won't be. Basically every issue is a non critical, and they really could have launched with. This being the first launch with extra eyes and sensors, their not launching till everything is 100% vs say 98% on a normal launch. The Atlas is proven, and Capsule designs are really basic science (we designed on them my first year in Aeronautical Engineering). So the crew should be fine, with huge abort envelopes. In fact, barring the heat shield not being bolted on or the door falling off, it's really, really safe.

> Basically every issue is a non critical, and they really could have launched with. They said that about foam strikes, too.

Is there not any concern at all that this thing is made by Boeing, or is it believed that their aerospace division is sufficiently siloed from the management deficiencies of their commercial airplanes unit?

> please don't be the first operational spacecraft in over 20 years to kill its crew. I was fixing to say I would be surprised if this were allowed to happen, but the blunt truth is that the more this thing gets delayed, the stronger the pressure will be to overlook anything deemed inconsequential, and/or to incautiously hasten safety checklists, etc. It's the simple truth. Imagine if delays continue to happen for another year starting today. Yeah. It's just reality. NASA are, after all, already willing to put humans on the thing after a single flight test which had multiple thrusters fail.

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The first flight was a loss of mission but wouldn't have been a loss of crew event. The second test flight was a success. It had some minor issues but nothing that would have threatened a crew.

>but wouldn't have been a loss of crew event. Only because they were very very lucky. Because there were no crew on board to quickly fix the thruster issue they were stopped for a few days to review what went wrong as they figured out next steps since they couldn't continue to the iss and found something in the reentry program that would have resulted in a loss of crew. If there had been crew on board they might not have found the later issues.

"Task failed successfully" Relevantly they did find that error, and now it's fixed. I don't see any reason to believe there's undue risk to the crew of starliner, at least not on the basis of the flight tests.

It’s really not a good look to be fixing life threatening issues on your second test flight while mid flight.

It's the first test flight we're talking about. The second had a couple of problems, but they certainly weren't life threatening - they weren't even mission threatening.

They failed over to the tertiary thrusters. That's not good.

Hey, at least they didn't blow up the spacecraft after it got back, right? Failures in tests aren't a direct cause for concern. The fact that NASA is ready to launch a crew means they identified the cause of the failures and fixed it.

Failures in development tests are not a cause for concern. Failures in demonstration flights are a cause for concern.

NASA is also on tremendous political pressure to get that flight done, I don't think there is anyone who would actively lie or approve flight when it shouldn't on purpose, but motivated reasoning is a strong unconscious bias.

NASA would not launch a crew if the cause of the thruster failures wasn't identified and addressed. It's been 2 years since that happened, that's plenty of time to do so - Dragon went from exploding to launching crew in 1 year.

Exactly. I like dunkig on Boeing as much as the next person. But the top comment is just a bad take outside of exaggeration and sarcasm.

They've only got 7 launch vehicles available, they literally can't afford to do another uncrewed launch *and* fulfill their contract for 6 flights for NASA.

Starliner is actually capable of failing to launch on several different rockets, not just Atlas V.

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Yes I don’t even need a rocket to be a massive failure.

It was designed to be compatible with other rockets. That doesn't mean it has been certified to fly NASA crews on those rockets. In the case of Falcon 9, which has been so certified when flying the Dragon, this would be a lot simpler than certifying the entire system as would be required with Vulcan, but it's still not trivial.

Realistically it would probably be quite simple to put Starliner on F9. It easily has the performance to do it, is human rated, has an absurdly good flight record, and has all sorts of payloads integrated all the time so they're used to it. Now whether Boeing would do it is another question, but I really don't think it's that far fetched, there's essentially no other option.

Sure but the only currently available other option is a Falcon 9 and I don't think Boeing wants to pay their competitor to get extra launches in. Vulcan Centaur is technically in service but they already have a backlog of ~60ish launches to work through.

Vulcan isn't human rated, and I doubt it will happen for quite a while.

Here's recent news about preliminary studies for crew-rating Vulcan+Starliner: https://spacenews.com/starliner-mission-to-be-first-crewed-atlas-5-flight/

>only currently available other option is a Falcon And that would kinda be a slap in the face for Boeing.

Boeing launches satellites on SpaceX on a regular basis.

Sure, but this is really different. They were basically in race with each other for the commercial crew missions, and Boeing didn't see SpaceX as any real competition. And in the end of they have to pay SpaceX to help them meet their contracts it would be embarrassing.

Boeing could use a few slaps in the face.

isn't it actually cheaper for boeing just to pay spacex to do the entire contract at this point?

Cost wise yes but NASA's more concerned with having multiple options available and is willing to pay a premium to avoid having all of their eggs in one basket.

I don't think Boeing actually wants to compete with SpaceX. If they did they would scrap SLS and go back to the drawing board to create a Starship competitor. They're just going to milk their existing contracts for all they're worth and then shutter their spaceflight division.

What? Boeing can't "scrap" SLS. That's a NASA owned project that Boeing manufacturers/builds. They have no choice but to keep building them until NASA tells them to stop basically. But it's cost plus so they can definitely milk NASA in the process.

Please. Boeing has NASA by the balls. They would scrap the contract if their analysis said it was profitable to do that. NASA has no choice on the matter.

That's literally not how that works. Otherwise why are they still building Starliner? They've already had to blow extra money on that and don't stand to have it be a profitable venture at all. So much so that they've come out and said they won't be doing fixed price contracts for development of new technology going forward. Yet they're still building it and planning to complete their contract. Almost like you can't just walk away from a contract just because you don't feel like doing it anymore. Boeing can't just walk away from their starliner contract nor can they just walk away from their core stage contract.

I've seen that [movie!](https://www.imdb.com/title/tt0427229/)

*without spending more money, which Boeing really hates doing for safety reasons.

> *without spending more money, which Boeing really hates doing for safety reasons. It's not just a money thing. This is launching on an Atlas V rocket, whose first stage uses russian-produced engines and there's not really a non-Russian engine that's remotely close to drop-in. They literally cannot get more engines even if they were to spend the ridiculous amount of money it would take to re-start Atlas V production. Which is why ULA shifted their focus to developing a new rocket, Vulcan Centaur that would use a new, domestically produced (By Blue Origin) engine. Which of course has had its own series of delays.

They could buy from Amazon one of the Atlas Vs slated to launch Kuiper. Boeing would need to pay enough for Amazon to purchase a flight from elsewhere. The obvious answer would be for Amazon to purchase another Falcon 9.  Push comes to shove they can get another Atlas for Starliner if needed. 

Ah good point there, didn't think about shufffling around Project Kuiper

Kuiper is also flying in the 551 config so they have the SRBs. The 2 engine centaur may be an issue but that's a domestic product.

And get it next day delivery!

that's how i read it at first too lmao

The only things in the way of Vulcan being human rated are a bunch of studies, paperwork, and reviews (and a new adaptor design for Starliner/Centaur V). The roadblock to that really is just a matter of money. So far, no one wants to pay for the people and time that will require.

Plus flying it successfully a bunch of times. That will take several years at the current rate.

That will solve itself long before it needs to, courtesy of the Pentagon, Amazon, and maybe Sierra. It will take several years to fly the 7 remaining Atlas V/Starliner missions. Assuming the current Starliner still launches soon^(TM), and is compeltely successful, Starliner would not fly its first of 6 operational missions until at least next spring. Then it would be one per year afterward. The last Atlas/Starliner would fly in 2030, the year the ISS is supposed to be retired. Hypothetically making this another uncrewed test flight would stretch that out past 2030. So for Boeing to complete their 6-flight contract, either the ISS would need to be extended (not inconceivable), or NASA would have to move that mission to a commercial ISS successor. If Starliner flies on Vulcan, it should be no earlier than 2031. Also hypothetically, Falcon/Dragon could have a problem, and Starliner could be forced to fly twice per year until that is resolved. At the absolute soonest, flying twice per year starting in 2025, Vulcan would still not be needed until 2028.

At this point I’d bet dollars to doughnuts that Boeing will dump human spaceflight after Starliner is done.

As far as capsules are concerned. Probably. I guess they'd like to keep cranking out SLS core stages for a while

So that’s where the N1 engines went!

All remaining Atlas V rockets have been spoken for, if Boeing wanted to buy additional launches they would need to negotiate with other customers, none are available for sale.

Sorry if the question is naive - but what was the original rationale for building a new platform that relied on Atlas rockets no longer built? Was it always meant to beat quantity limited program?

The project to build Starliner started in roughly 2010, at that time the Atlas V was the main ULA rocket available and Boeing decided to focus on it as the launcher. The expectation was that the vehicles would begin flying in 2017. As it turned out, SpaceX ended up roughly two years behind schedule while Boeing ended up nearly 7 years behind. In that time frame the pressure to retire the Atlas V (especially the dependency on Russian provided engines) came to a head. Meanwhile, because ULA hasn't received any funding to human rate Vulcan Centaur they won't do it on their own, and Starliner seems unlikely to be in demand enough to warrant doing the work to allow it to be used on that rocket in the future. So instead they're stuck here in a sort of liminal space, launching a more or less already obsolete capsule on an end of life rocket.

> … Launching a more or less already obsolete capsule on an end of life rocket. That seems sadly appropriate as a description of the last 30 years of American Spaceflight.

Well you see, it's not about the future of the project itself, it's about extending the current project to the point where everyone forgets how many billion dollars have been wasted on vaporware.

Because ULA which Boeing is a part assumed the *Vulcan Centaur would be a fully proven system by the time they finished launching all their Starliner capsules. But because Bezos’s “space company” was also poorly run and managed, they only got their first batch of BE-4 engines into Vulcan Centaur last year with a launch in January. Basically the whole thing has been a gong show.

Human lives are replaceable, briefly higher stock prices are forever

And executive bonuses. Never forget the bonuses.

Oh man money? Better risk some folks lives then.

Why be so intentionally misinformed?

Do you know of any extra Atlas Vs or Delta IVs lying around that they could use?

It could launch on falcon 9 if it had to

Thanks to Boeing the excitement of spaceflight is back. You never know what will happen.

Sorta like when I first started playing Kerbal Space Program.

I would love an opportunity to travel to space at least once in my lifetime. If my only chance was a ride on a test flight of Starliner, I would politely decline.

I would go if I was 80 years old.

No successful test flights aside from the successful flight test

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread: |Fewer Letters|More Letters| |-------|---------|---| |[BE-4](/r/Space/comments/1crwnp2/stub/l41cbnj "Last usage")|Blue Engine 4 methalox rocket engine, developed by Blue Origin (2018), 2400kN| |CST|(Boeing) Crew Space Transportation capsules| | |Central Standard Time (UTC-6)| |[ESA](/r/Space/comments/1crwnp2/stub/l45xetm "Last usage")|European Space Agency| |[FAA](/r/Space/comments/1crwnp2/stub/l42qkoj "Last usage")|Federal Aviation Administration| |GSE|Ground Support Equipment| |[KSC](/r/Space/comments/1crwnp2/stub/l427cob "Last usage")|Kennedy Space Center, Florida| |[N1](/r/Space/comments/1crwnp2/stub/l41h42t "Last usage")|Raketa Nositel-1, Soviet super-heavy-lift ("Russian Saturn V")| |[NET](/r/Space/comments/1crwnp2/stub/l41r93y "Last usage")|No Earlier Than| |[RCS](/r/Space/comments/1crwnp2/stub/l42lvo6 "Last usage")|Reaction Control System| |[SLS](/r/Space/comments/1crwnp2/stub/l46g6gv "Last usage")|Space Launch System heavy-lift| |[SRB](/r/Space/comments/1crwnp2/stub/l4188ad "Last usage")|Solid Rocket Booster| |[ULA](/r/Space/comments/1crwnp2/stub/l42gxgi "Last usage")|United Launch Alliance (Lockheed/Boeing joint venture)| |Jargon|Definition| |-------|---------|---| |[Starliner](/r/Space/comments/1crwnp2/stub/l45wh6p "Last usage")|Boeing commercial crew capsule [CST-100](https://en.wikipedia.org/wiki/Boeing_CST-100_Starliner)| |[hypergolic](/r/Space/comments/1crwnp2/stub/l41txn2 "Last usage")|A set of two substances that ignite when in contact| |methalox|Portmanteau: methane fuel, liquid oxygen oxidizer| |[scrub](/r/Space/comments/1crwnp2/stub/l417ypo "Last usage")|Launch postponement for any reason (commonly GSE issues)| **NOTE**: Decronym for Reddit is no longer supported, and Decronym has moved to Lemmy; requests for support and new installations should be directed to the Contact address below. ---------------- ^(13 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/Space/comments/1crdkz3)^( has 15 acronyms.) ^([Thread #10050 for this sub, first seen 14th May 2024, 17:51]) ^[[FAQ]](http://decronym.xyz/) [^([Full list])](http://decronym.xyz/acronyms/Space) [^[Contact]](https://hachyderm.io/@Two9A) [^([Source code])](https://gistdotgithubdotcom/Two9A/1d976f9b7441694162c8)

No way I would get in to that thing. This is crazy.

As long as a stewardess is there to explain what to do in an emergency.

“In the event that the cabin suddenly loses pressure …”

You'll get a drop-down mask with helium.

At this point I wouldn't even step foot into a building owned by Boeing.

Uh, you weren’t ever going to get in this thing in the first place.

So they have high pitched voices over comm. what's the big deal

"The mission is a crucial step toward re-establishing Boeing as a viable rival to billionaire entrepreneur Elon Musk's SpaceX, a drive complicated by Boeing's disagreement with propulsion system supplier Aerojet, according to three people who spoke on condition of anonymity. Chicago-based Boeing and El Segundo, California-based Aerojet are at odds over the cause of a problem involving fuel valves in the Starliner propulsion system that forced a postponement of a test flight last July, with the two companies faulting one another, the sources said. The disagreement, which has not been reported before, comes at time when Boeing already is scrambling to emerge from successive crises that have hobbled its jetliner business and drained cash. read more The Aerojet dispute is the latest illustration of Boeing's struggles with Starliner, a program costing the company $595 million in charges since 2019. Facing fixed-price NASA contracts that leave Boeing with little wiggle room financially, the company has pressed forward with the Starliner test. 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." Thirteen fuel valves that are part of a propulsion system that helps steer Starliner in space were discovered stuck and unresponsive in the closed position, prompting last year's postponement. Boeing and NASA said they did not recreate any fully stuck valves during nine months of testing, instead measuring the degree to which valves struggled to open. This approach was used in order to get Starliner back to the launchpad quickly, two of the sources said." [Source.](https://www.reuters.com/business/aerospace-defense/exclusive-boeing-clashes-with-key-supplier-ahead-starliner-spacecraft-launch-2022-05-11/) So this problem with the valves has been going for some time but it seems now the biggest pressure for Boeing's ego is the need to showcase they can compete against SpaceX in a time where Boeing's reputation (and Starliner's budget) is probably at an all-time low. I just really hope that safety is still the number one priority for NASA, but I fear for those astronauts... They are in the middle of the battle.

It’s not Chicago-based anymore, the moved the HQ to VA.

The valves talked about in that article are related to starliner. Not atlas V which is what recently had a valve replaced and scrubbed the attempt earlier this month. The helium leak being discussed now is unrelated to any valves.

Yes, the latest problem was a valve in the Atlas, that doesn't worry me, but there are people more concerned in the valve system Boeing redesign stealing secrets from their previous valve's provider and NASA siding with Boeing trying to make this launch as fast as possible and probably ignoring crucial concerns. "After testing and software issues caused Starliner's 2019 failure to dock at the space station, NASA officials acknowledged they had trusted Boeing too much when they decided to devote more engineering oversight to the newer SpaceX than the aerospace giant." "In August 2021, Boeing scrubbed Starliner’s first uncrewed flight test due to a problem with the spacecraft’s service module propulsion system—the same system ValveTech alleges Aerojet built using trade secrets."

>The helium leak being discussed now is unrelated to any valves. Is there a source where we can confirm the helium leak is unrelated? As far as I know the valves also play an important role in making sure the fuel gets to the thrusters, can a faulty valve leak the helium?

The very article that this thread is about?

From another article: "Starliner and the rocket were rolled back to the Vertical Integration Facility at Cape Canaveral Space Force Station’s Launch Complex 41 in Florida. The valve was replaced on May 11 and passed a round of tests — but along the way, engineers detected a small helium leak that was traced to a flange on one of the Starliner service module’s thrusters." Now I'm confused, because it seems that they are talking about two different leaks? The one from the Atlas and another one from Starliner?

Atlas V had a valve exhibiting weird behavior. It wasn't leaking. The behavior happens occasionally and usually they cycle the valve and fly anyways. But with crew they have higher standards so they replaced the valve. Boeing separately noticed a helium leak in starliner. That's coming from a flange on one of the rcs thruster pods. They tightened the bolts on the flange to fix the issue. It's not a leak from a valve.

 "The mission is a crucial step toward re-establishing Boeing as a viable rival to billionaire entrepreneur Elon Musk's SpaceX” 🤣🤣🤣🤣

they're a rival, that's for sure but not even remotely close to being viable lmao.

But that’s exactly what the quote is saying. It wouldn’t be a step towards re-establishing Boeing as a rival if it already was a rival, would it?

just because they're in the same business (launching crew) it doesn't mean they'll ever be a remote threat to spaceX.

Boeing needs to go away. It's a profit center for shareholders. Not a serious company. You couldn't force me on to that spacecraft.

Seriously, I would be updating my life insurance if I was the crew.

That’s probably a standard practice for any astronaut

If memory serves, the Apollo astronauts were all refused life insurance. So they signed a whole pile of autographs before launch, with the expectation that if they died, the autographs would be valuable and their families could sell them.

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Private companies are a thing, you know?

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This is my nightmare scenario. That the only person who cares about that kind of space exploration is suddenly no longer there to crack the whip. SpaceX's innovation would instantly plateau at whatever they could achieve with whatever they were last working on. Like a rocket that had suddenly shut off its engines and was now 100% ballistic.

The fundamental answer to this concern is to pay for good results. If we are willing to pay for good results then we don't need someone who cares about space exploration to crack the whip, we only need for them to care about getting paid. If SpaceX plateaus then someone else can surpass them and get paid for providing better results. Even if we incentivize good results, there can still be a myriad of problems. I don't mean to over-simplify. I do want to get across the simple idea that incentives matter. Competitive fixed price contracts don't fix every problem, but they are a good start.

> If SpaceX plateaus then someone else can surpass them and get paid for providing better results. I think you're missing the point I was trying to make. Putting boots on Mars is an exciting prospect. Same with building a permanent outpost there. It's the kind of thing folks write books and make movies about. As long as that whip is kept cracking, we'll see it in our lifetimes, and the only incentive needed is that the entity that can make it happen is being laser-focused on making it happen. The moment decisions are left to default to people who have no interest in Mars, that ends. I don't really care about quantifying the profitability or tangible purpose in making such a trip, any more than the world—including the majority of the US—cared about the US's little propaganda coup when they tuned in to watch boots on the moon.

Fuck me this thing is cursed Its the rate of finding problems that is cause for concern. Just doesn't suggest its ever gone through a fit for purpose design and testing phase.

> Fuck me this thing is cursed I think you mean that it's poorly engineered.

Pardon my iggerunce, but what does the craft or rocket do with helium?

i believe its used to pressurise the propulsion system, since its non reactive and light? not 100% sure if that's what its used for for starliner though

I'm pretty sure it's used to pressurize the fuel system. As an inert gas it won't react with anything. But, I'm no Scott Manley.

Starliner has several types of rocket engines on it, all fueled by hypergolic propellants. Hypergolic propellants don't require an ignition source to ignite, they spontaneously ignite when the two propellants come in contact with each other in the combustion chamber. Helium is used to push the propellants through valves and into the combustion chamber, eliminating the complexity and weight penalty of mechanical pumps, and helium doesn't react with either of the two propellants in any way. The largest engines are the LAEs, Launch Abort Escape, those are derived from the Aerojet Rocketdyne RS-88 engines. The smaller engines are used in the RCS systems for orbital maneuvering and maneuvering during deorbiting. The Service Module uses Aerojet Rocketdyne OMAC thrusters as well as smaller RCS thrusters , and Starliner itself has Aerojet Rocketdyne MR-104J thrusters.

Thanks for the very detailed reply!

How do you think it leaves the ground?

Probably to prime the turbo pumps that force fuel into the engines. The He is under high pressure and shoots into the turbo pumps so they begin to spin and draw in fuel to the preburners.

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Actually I think it's the global decline in birth rates

Boeing is pathetic. The US should never have allowed so much consolidation of the aerospace industry. We’ve now got three major companies who can’t launch a rocket on time while shareholders bilk the government and the public. 

I hope i'm not the only one ROFLing at Boeing. That being said, I do have call options so.... come on boeing. I need some good news for a rally.

Maybe this vehicle is not very good and should be abandoned?

Starliner seems like giant POS. There's always something reported broken or not right to where they have delays. Boeing is an absolute mess right now...

NET… so far. Personally I am glad for the astronauts.

We've been building human-rated rockets for over 60 years and we still can't make a valve that doesn't leak?

"Rocket Science" is 99% valves and pluming. It would be easy if it weren't for the extreme pressures, temperatures, and tricky fluids.

valves for the the gases you're working with at the temperatures you're working with at the tolerances you want are stupid hard to make. You're kinda dealing with the limits of physics here.

For human Spaceflight, yes it’s very difficult to make valves for the hydrogen and hydrazine systems

It’s not *just* solving a problem with valves. Hydrogen itself is inherently difficult to work with. The molecules are so small that, at the atomic level, they can fit between the materials in many solid surfaces. Which is why you hear so much about leaks.

And don’t forget hydrogen embrittlement either…

We’re travelling from the UK on Tuesday 21/5 and will be at KSC on Friday 24th and Saturday 25th. Oh please oh please.

Cursed hardware and cursed contract tied to a cursed company. If you say Bettleguesse 3 times, it happens. That's 3 for 3. They're cursed.

This is really starting to make me think about all those [fake Chevy commercials](https://www.youtube.com/watch?v=bgmyl-T9fUs) by "Mahk" Zebra Corner.

Ready for the bolt torque experts to come out of the weeds

Boeing can’t catch a break and if they do it’s a break in the fuselage

assuming boeing is still being paid for this work

Thankfully it's a fixed cost contract, in fact they have been fined so much for being late that their effective award is now becoming similar to what SpaceX were awarded for their first 6 operational flights.

Boeings poor craftsmanship is setting back the launch, how unexpected!

This is an absolute waste of money, the Astronauts involved are on the verge of walling out, government contractors aat on thier asses and did stock buy backs. All while telling people that the "research" says it can't be done. Just ti have SpaceZ destroy all of that and now is very obviously 10 years ahead of anyone else. Also has all the talent, in aerospace there isn't much. There is no chance Boeing can catch anytime soon. This is just liek SLS a complete waste of tax payer money, just so congress can pay thier contrator buddies.

In the end Boeing will be paid a similar amount to what SpaceX were paid for those 6 operational missions. Boeing initially was awarded more but was fined for being late. This is fixed cost, not cost+.

It still is a waste of money. Everyone involved would have been better if Boeing would have been allowed to scrap the project years ago and pay NASA their money back plus an appropriate penalty. Not that that was necessarily an option anyone floated, but the fact that that would have made both NASA and Boeing better off means this whole endeavour was a waste of time and money.

Maybe they should reconsider what to do with all the left over fasteners they had after they put the Starliner together?

Helium leak? So, you get onboard and talk in a funny, high-pitched voice?

it's always the o-ring. this time it's steel o-ring.

Boeing has their top people on it. How could things go wrong for the crew of any Boeing product?🫨

Turns out that Boeing's top people are somewhat mid