SpaceX And/Or Rocketry In General

Anonymous

Here are some pics from the

Here are some pics from the backyard:
[EDIT] Sad ending. But every launch is a first launch. After all this IS rocket science.


Mike Hewson
Mike Hewson
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Something at the forward end

Something at the forward end let go. I'm gutted ...

Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

archae86
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RE: Something at the

Quote:
Something at the forward end let go.


Good call. Second stage O2 tank over pressure. From a "counterintuitive" cause.

Well, the intuitive causes would be excess top-up not leaving enough margin for expect heating during launch, or higher than expected heating during launch. So I wonder what that leaves. Unless the pressure reached was the expected one for the phase of flight, and a discrepantly manufactured tank just could not hold that? I guess there are a great many possibilities.

Anonymous

In addition to the obvious

In addition to the obvious downside of today's event lets not forget that this is the second ISS resupply failure within a short period. This most certainly will have an impact on the ISS crew.

[Edit] I downsized the pics on my server because I think they were causing some issues with follow on posts.

Mike Hewson
Mike Hewson
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RE: RE: Something at the

Quote:
Quote:
Something at the forward end let go.

Good call. Second stage O2 tank over pressure. From a "counterintuitive" cause.

Well, the intuitive causes would be excess top-up not leaving enough margin for expect heating during launch, or higher than expected heating during launch. So I wonder what that leaves. Unless the pressure reached was the expected one for the phase of flight, and a discrepantly manufactured tank just could not hold that? I guess there are a great many possibilities.


"Counter-intuitive" has got to mean a leak of some sort. Causing ice to form on a valve that would have bled pressure. There is a similiar issue with throttle icing in some venturi throat carburetor designs.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

MAGIC Quantum Mechanic
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archae86
archae86
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robl: thanks for the

robl: thanks for the downsize. They were coming in slow here.

robl: I watched parts of the NASA post-event press conference. The NASA guy was moderately upbeat regarding near-term supplies impact on operations. He said they aim for about 6 months supplies as desired safety stock, and are currently down to about 4. Not only are they not yet low enough to start planning retrieval of current crew, they still currently plan to do the next crew launch upsizing from three to six.

In the relatively near-term there is scheduled a Progress delivery with July 3 launch, and an HTV (Japanese) delivery with August 16 launch. HTV is big (about 16,000 pounds useful cargo). Now if that one fails, things will look much bleaker.

On track record, I'd guess SpaceX will come up with a conclusion and a believed-adequate fix in fairly short order. The bigger question for ISS is how quickly NASA will go through whatever administrative process they have to allow another SpaceX delivery attempt. The bigger question for SpaceX as a company is whether the huge expense (to both SpaceX and the US government) expended on the very recently declared SpaceX certification will be considered not enough, and SpaceX go back into the waiting line behind ULA for the non-NASA US government payloads.

Despite the way I phrased that, I suspect that both the diagnosis and the fix by SpaceX will be suitable to this particular problem. The unanswerable question from available data is whether the SpaceX work, much as I like them, is riddled with more such weaknesses, or this was just really bad luck on an obscure case.

By phone link to the press conference, the SpaceX CEO heavily hinted that it may be a while before they tell us more of what they think happened. She emphasized that they want to get right what they tell the public, and not find themselves withdrawing announced conclusions after further study. She specifically mentioned that Elon's postings were "forward leaning" or words to that effect. "Managing the boss" must be an interesting aspect of her job.

Mike Hewson
Mike Hewson
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Hmmm. Well I guess "knocked

Hmmm. Well I guess "knocked into a cocked hat" is a reasonable feeling that SpaceX as an organisation may be collectively feeling. Well I feel a bit like that at least and it's not even my money. I'll armchair guess ( as always ) :

- they're not really sure of what the heck happened and that scares them.

- they are pretty sure of what happened and ( like the Sirius Cybernetics Corporation in The Hitchhiker's Guide To The Galaxy ) a superficial design flaw has been covering a deep design flaw or similiar. That is, they have a big re-design/re-work/re-validate task ahead. That scares them.

- regardless of cause, schadenfreude from Wall Street ( investors and not just as expected from competitors and wingnuts ) scares them.

Now, from the YouTube video* this is the last 'normal' frame ( 200.47 ) :

... compared to the very next frame ( 200.51 ) which shows a very slight whitening/blurring of the forward end ( circled ) :

Here's eight seconds after the top section blew but just one frame ( 208.49 ) before it's just a ball of nonsense, I think there is a still operating 1st stage engine ( circled ) :

... with the remainder disintegrated/ing before it.

Cheers, Mike.

* You can scroll frame by frame at http://rowvid.com/ by supplying the video url, in this case PuNymhcTtSQ ie. http://rowvid.com/?v=PuNymhcTtSQ. You want to be at about 3:20 + here.

( edit ) As usual the YouTube comment section is fit for standup comedy without further drafting. Clearly there are plenty Peter Griffins out there who just can't edit their thought-to-speech pipeline. There's one thread that starts :

Quote:
Goto 3:20 for it to happen


and winds up after 58 replies with :

Quote:
I think it's bad that you call your police officers - "rednecks and hillbillies" .....


.... seriously I don't think you could get that sort of stream of consciousness even if you paid for it. After 20+ years of internet can no-one spot trolls anymore ? :-)

( edit ) BTW the expanding white cloud is because liquid oxygen became gaseous oxygen at the price of liquifying/freezing the water in the air. So especially that doesn't give you a 'kaboom' as would be expected from detonation of a fuel/O2 mix. Note the last recorded speed was 4722 km/hr. That's plenty to rip a non-aerodynamic configuration to shreds.

( edit ) I've got to stop reading the comments ! They are doing my head in. There are so many EEG ( electroencephalograph ) flatliners out there. It is amazing the number of people who knew/know all about the problem but never mentioned it at a more useful time ie. last week. :-) :-)

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

Mike Hewson
Mike Hewson
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I've been locked onto the

I've been locked onto the footage every spare minute today. I think the Dragon capsule made it out intact. But give me a few days ....

Cheers, Mike.

( edit ) I mean made it out of the RUD zone way up, I don't mean surviving to sea level necessarily. It would have hit the ocean going supersonic.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

Anonymous

While watching the actual

While watching the actual launch sequence I noticed that up near the top of the rocket where the "claw" wraps around the rocket there was a lot of ice forming and it was flaking off and falling away. I just assumed that with the heavy humidity and cold temps that this would be a normal event. The shuttle experienced similar behavior. I am now wondering if maybe what I saw was not excessive, especially after seeing the frames Mike cut out from the youtube video post showing that the "head" seemed to have a problem. Also in the video that Magic referenced did I see some sort of horizontal fire prior to detonation? Almost like the head thrusters used for landing orientation had activated. Of course this is pure chatter on my part.

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