SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD (2)

[rsdavis9]

Considering that the COPVs, the helium in them, and the whole aluminium LOX tank starts at more-or-less ambient temperature, **of course** the lox will vigorously boil when contacting it. There is a temperature difference of some 200K between the boiling point of LOX and the container you are putting it in.

This is normal.
This is expected.
This is ludicrously unlikely to be the cause of failure.

Thermal shock?

[JamesH65]

Why is it that so many people think the SpaceX engineers are so stupid they won't have thought of all this stuff?

The same engineers that put the first commercial rocket in to orbit, the same engineers that docked a commercial capsule to the ISS for the first time, the same engineers that landed a orbital booster in one piece.

I'm not a rocket scientist/engineer. They are. It's why I am happy to await their results, and believe them when they are released.

Bad day in the office. Grump.

 

[FinalFrontier]

Why is it that so many people think the SpaceX engineers are so stupid they won't have thought of all this stuff?

The same engineers that put the first commercial rocket in to orbit, the same engineers that docked a commercial capsule to the ISS for the first time, the same engineers that landed a orbital booster in one piece.

I'm not a rocket scientist/engineer. They are. It's why I am happy to await their results, and believe them when they are released.

Bad day in the office. Grump.

Why is it that you think engineers are above the laws of physics and causality?

Almost every major technical or industrial disaster in history involved engineers thinking they had something right or telling others they had something right or "that can't possibly happen" and then it did. People make mistakes. The goal is to find out why and make changes so you don't make the same mistakes repeatedly, and hopefully make fewer mistakes in the future when it really counts (like when they have a crew on top of the vehicle). Elon Musk himself know's this and has said it repeatedly. Space is hard ect.


Why do you keep throwing out this appeal to authority as if that some how nullifies all of the facts, data, and points posters have presented in the last two threads?

And why are you so desperate to find some way, some possible excuse, ANY excuse to absolve SpaceX and the Falcon 9 of any possible criticism whatsoever? You did this in the last thread too.


It was not the "first commercial rocket" either because they already had COTS funding and I can argue Dragon was not the first "commercial" spacecraft either because technically speaking STS was operated worked on and built by private companies on contract for NASA like every other spacecraft in American history.


This is the last time I will be replying to you. I don't know if you are trying to bait people or being sarcastic or what, but your posts increasingly don't make any sense to me so either I'm crazy or us old folks just don't understand new speak 

[FinalFrontier]

Anybody think that they loaded warm helium too fast might be part of the problem? Maybe the copv's were so hot that they vigorously boiled the lox...

That is some of the discussion around was it a (1) problem in the stage or a (2) problem in the GSE that caused the stage to fail.

The GSE is different for each site and the GSE at LC-40 is now destroyed. If the telemetry they recovered does not rule something like what you described out, then it would be likely that aspects of filling would be tested in McGregor to see if there are similar signatures to what they saw in LC-40.

However, there are more factors to consider beyond flow rate of He; that's what the investigation is likely doing - identify potential failure modes that can be supported by the data they have in hand, get data to rule out some assignable causes, repeat.

If it were GSE why did the stage pass acceptance testing at McGregor and not explode there?


Better question still: How did the stage pass acceptance testing at McGregor and tanking testing, ect, and not explode there?

[Mike_1179]

If it were GSE why did the stage pass acceptance testing at McGregor and not explode there?

Better question still: How did the stage pass acceptance testing at McGregor and tanking testing, ect, and not explode there?

Could be related to the fact that GSE is different at McGregor and at LC-40. But it also could be a number of other things, most of which we don't know about because we're not privy to the tiny details of the vehicle, GSE and operating procedures.

These are the branches of the fault tree that the investigation team is working through.

[atsf90east]

If it were GSE why did the stage pass acceptance testing at McGregor and not explode there?


Better question still: How did the stage pass acceptance testing at McGregor and tanking testing, ect, and not explode there?

I'm wondering if the fill procedures used for acceptance testing at McGregor were exactly the same as used on the previous successful launches, but with the experimentation on fill rates, etc. done at SLC-40 to gain some hold time the gaseous helium system was over-stressed to the point of catastrophic failure?  All it would take is for one line to crack, or one fitting to fail.

[JamesH65]

Why is it that so many people think the SpaceX engineers are so stupid they won't have thought of all this stuff?

The same engineers that put the first commercial rocket in to orbit, the same engineers that docked a commercial capsule to the ISS for the first time, the same engineers that landed a orbital booster in one piece.

I'm not a rocket scientist/engineer. They are. It's why I am happy to await their results, and believe them when they are released.

Bad day in the office. Grump.

Why is it that you think engineers are above the laws of physics and causality?

Almost every major technical or industrial disaster in history involved engineers thinking they had something right or telling others they had something right or "that can't possibly happen" and then it did. People make mistakes. The goal is to find out why and make changes so you don't make the same mistakes repeatedly, and hopefully make fewer mistakes in the future when it really counts (like when they have a crew on top of the vehicle). Elon Musk himself know's this and has said it repeatedly. Space is hard ect.


Why do you keep throwing out this appeal to authority as if that some how nullifies all of the facts, data, and points posters have presented in the last two threads?

And why are you so desperate to find some way, some possible excuse, ANY excuse to absolve SpaceX and the Falcon 9 of any possible criticism whatsoever? You did this in the last thread too.


It was not the "first commercial rocket" either because they already had COTS funding and I can argue Dragon was not the first "commercial" spacecraft either because technically speaking STS was operated worked on and built by private companies on contract for NASA like every other spacecraft in American history.


This is the last time I will be replying to you. I don't know if you are trying to bait people or being sarcastic or what, but your posts increasingly don't make any sense to me so either I'm crazy or us old folks just don't understand new speak 

Not quite sure why you are having such a go at me for pointing out issues. But hey ho.

In answer to all your engineering points in one go - the SpaceX engineers have access to the data. Everyone here doesn't. You say people here are putting out "all of the facts, data, and points ". Well, sorry, but the number of facts available to all outside SpaceX is 2 (it exploded, it was the helium system). Everything else people are saying is conjecture and guesswork. I really find it odd you cannot see that. What other 'facts' do we have?

Note, I'm not saying that people here are wrong, I'm saying that you cannot claim anything without the data. Which is what people are doing. You claim related to CRS-7 - no evidence.  You claim SpaceX have quality issues - No evidence. Evidence may of course turn up, in which case the conjecture moves closer to fact.


I'm 50 BTW, that classes as old I believe. And I am of the opinion that this is an manufacturing or engineering mistake, with a side dose of human error. Which covers everything I think. But with the facts available I am not even going to try and guess what the actual problem is. I'm going to trust engineers with a LOT more experience than me to do that. I'd suggest others do the same.

I'm out now. It's simply not worth any more of my time.

[Rocket Science]

...

No point talking about landing of Mars if you can't get to orbit reliably much less off the pad.

This is just an empty rhetoric, sorry

If you want to play in the "big leagues" you have to put on and "wear the big boy" pants...

EM does not want to play the "big leagues". He will play there only as long as he has to, which is not long now. He's in the business of building his own league. Look at ULA trying to redesign their pants to fit their shortened legs :-)

I'm channeling my inner Gus Grissom "How are we going to get to the moon if we can't talk between two or three buildings?" So I repeat "how are you going to get to Mars if you can't reliably, get to orbit much less off the pad"? I know realty sucks, stay real...

[FinalFrontier]

Note, I'm not saying that people here are wrong

That is exactly what you were saying.

In answer to all your engineering points in one go - the SpaceX engineers have access to the data. Everyone here doesn't. You say people here are putting out "all of the facts, data, and points ". Well, sorry, but the number of facts available to all outside SpaceX is 2 (it exploded, it was the helium system). Everything else people are saying is conjecture and guesswork.

For exact failure mode yes but you missed the point yet again what we are discussing is why and how they got to the point where they had a second failure. And there have been facts and data and points posted regarding this (as well as regarding what the exact mode may have been itself) and you are insisting that these are not relevant simply because they did not come from SpaceX.

We do not have the internal data of SpaceX and I am not implying nor have I implied that anybody here does or will. Nor am I implying nor have I implied nor has anyone here implied that we would know more than them about the exact failure mode IE what broke in this case in this incident, what we were discussing and have been discussing is less specific.  I am also not implying any of us know more than the SpaceX engineers regarding this specific failure, and if you read my posts you would know that. Not sure why you are missing this and I am sure I don't care why.

I'm saying that you cannot claim anything without the data.

No one has claimed anything without the data and nobody is attempting to with regard to SPECIFIC failure mode we are offering only conjecture on that. This again, has nothing to do with quality control or manufacturing culture or processes for which we do know things about some of which come from the CEO's own statements.

What you are claiming is that nobody can claim to criticize SpaceX for these issues without knowing the exact data behind this specific failure mode and that is ridiculous because they would not be having failures if they did not have these issues. And that has been proven. What they do about it is what the discussion is going to focus on in the future and whether they stick to their own changes. But that is for later on.

You claim related to CRS-7 - no evidence.  You claim SpaceX have quality issues - No evidence. Evidence may of course turn up, in which case the conjecture moves closer to fact.

Evidence has been presented for both of these. I have not claimed related to CRS 7 in the EXACT failure I have in fact said its already been proven its not the same problem, the relation is in how they make and test their components. There is a relation there and that is proven, with facts by the way, because the fact is the same part of the vehicle blew up and blew the vehicle up AFTER having passed acceptance testing and checkout. The problem though different was still missed, and still cost a payload. The CEO himself has said there is a complacency problem. Mounting a payload on a vehicle which is undergoing a test supposedly for the purpose of mission assurance and LESS risk to the payload which then explodes because of a problem quality assurance should have already detected is complacency defined. You can deny this all you want it doesn't make it any less true.

Not quite sure why you are having such a go at me for pointing out issues.

Because you are impugning other posters in how you do this and not pointing out the issues. You also seem to be denying reality or intentionally avoiding specific posts, evidence, and facts where and when it suits you. And it sure seems like the only reason you were doing it is to find some possible way to suggest SpaceX and F9 are absolved of any criticism for this. If I had to guess where this narrative goes it's probably along the lines of this: Once they do find the problem and fix it "Oh well its just a one off incident and see they fixed it! Everything is good now no problem at all!"

That was fine for CRS7 that will not be adequate this time for anybody here, for any of their competition and most especially for their customers. And they know it which is why I fully expect they will do more than that. Why you feel the need to do their work for them is beyond me.

And I am of the opinion that this is an manufacturing or engineering mistake, with a side dose of human error. Which covers everything I think. But with the facts available I am not even going to try and guess what the actual problem is.

Yes you are now that you realized you can't argue the straw-man anymore.

I'm going to trust engineers with a LOT more experience than me to do that.

Nobody suggested otherwise with regard to learning what broke, but what you did do is suggest that nobody can claim they have quality and mission assurance issues because the engineers that work there haven't said they do.
Which is something they will never say they do even if they know they do, that is outside the scope of exact failure mode and of what an engineer does. And surprisingly, the CEO has said its been a problem in the past, which once again shows he really knows what he is doing and that they are trying to learn from these things, but that they do still have a problem.

I'd suggest others do the same

For once we agree on something.

[FinalFrontier]

...

No point talking about landing of Mars if you can't get to orbit reliably much less off the pad.

This is just an empty rhetoric, sorry

If you want to play in the "big leagues" you have to put on and "wear the big boy" pants...

EM does not want to play the "big leagues". He will play there only as long as he has to, which is not long now. He's in the business of building his own league. Look at ULA trying to redesign their pants to fit their shortened legs :-)

I'm channeling my inner Gus Grissom "How are we going to get to the moon if we can't talk between two or three buildings?" So I repeat "how are you going to get to Mars if you can't reliably, get to orbit much less off the pad"? I know realty sucks, stay real...

Fixing what caused the over-pressure event should be relatively simple. Even if it was COPV, options for alternative materials for COPV use have already been posted, as well as moving away from composite tanks entirely, though it seems more likely now that something else in the helium system failed since COPV has not been specifically mentioned in the most recent statements by SpaceX (as Jim pointed out).


The hard part here is the culture and mission assurance changes, but not even so much when it comes to implementing them. The hard part will be sticking to them.

[CyndyC]

There's something fishy about the most recent update anyway. Is there anyone here who didn't already know that the helium system was breached? Put in another way, would you have believed an update that said thankfully the helium system was not breached?

They probably just wanted to say something, anything to clear Elon Musk from being bombarded with questions he can't or doesn't want to take time to answer at the Mars presentation today.

[Fan Boi]

COPV don't implode, unless you can teleport it to the Mariana Trench.
My gut feeling is that they won't change hardware/components because of this failure, they will change a procedure.

[dorkmo]

They probably just wanted to say something, anything to clear Elon Musk from being bombarded with questions he can't or doesn't want to take time to answer at the Mars presentation today.

seems like he got a couple of crazy questions anyway lol

[as58]

There's something fishy about the most recent update anyway. Is there anyone here who didn't already know that the helium system was breached? Put in another way, would you have believed an update that said thankfully the helium system was not breached?

I remember many people in the first thread 'knowing' that there was some kind of mysterious fuel-air explosion outside the rocket that was caused by whatever was the person's favourite. And many other theories. Now many of the same people who seemed very sure about their now-discredited theories have moved to 'knowing' how exactly the helium system breach happened. Often wrong, but never in doubt...

[mme]

https://twitter.com/jeff_foust/status/780893099501326336

Jeff Foust
‏@jeff_foust
Musk: F9 anomaly investigation still top priority; “most vexing and difficult thing.” Ruled out all the obvious possibilities. #IAC2016

[Jimmy_C]

I'm guessing what other sources of problems in the He system could cause the accident besides a previously damaged COPV. SpaceX previously had problems with parts of the second stage freezing. They rectified this by adding insulation around the cold pipes in the stage. Could the insulating not be sufficient for the subcooled LOx or RP-1? With less space in the second stage, too cold of an environment might cause valves to stick, seals to fail, or other problems. Sticky valves might show up on telemetry, but what other problems are possible that wouldn't show up? Could LOx leak into the He pipes?

[envy887]

I thought the helium system was supercritical, i.e. neither liquid nor gaseous, but both.

There is a line item in the Falcon 9 countdown that references liquid helium loading.

[HMXHMX]

I thought the helium system was supercritical, i.e. neither liquid nor gaseous, but both.

There is a line item in the Falcon 9 countdown that references liquid helium loading.

No, it is 5000 psi gaseous helium.

[NaN]

I thought the helium system was supercritical, i.e. neither liquid nor gaseous, but both.

There is a line item in the Falcon 9 countdown that references liquid helium loading.

No, it is 5000 psi gaseous helium.

They refer to the LOX-submerged helium system as "cryo helium" or "cryogenic helium system" which can fool people into thinking it's liquid helium. It's gaseous helium system submerged in liquid oxygen.

[sewebster]

I thought the helium system was supercritical, i.e. neither liquid nor gaseous, but both.

There is a line item in the Falcon 9 countdown that references liquid helium loading.

No, it is 5000 psi gaseous helium.

Isn't helium at 5000 PSI supercritical?