Author Topic: Starship Launch Mount / Pad / Table Discussion  (Read 262749 times)

Offline Lars-J

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #20 on: 04/24/2023 12:00 am »
Question is how much time this actually cost them.

Is the 1-2 months claim pure "Elon Time" or is there a logic behind it?

The truth is that they don’t know yet. So many systems that appear undamaged could have taken damage. It will likely take weeks to know the full extent of the damage.

Maybe Elon is using a “worst case scenario” (complete rebuild) when he made that estimate, but I highly doubt it. A complete rebuild would take longer.

“Elon time” statements usually assume that everything will go fine, so best case scenario.

Offline meekGee

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #21 on: 04/24/2023 12:01 am »
I fear that one of the things they learned from this is that some failures are more painful than others. …….. It's entirely possible that waiting for a deflector to be built would have been faster than launching without it.

Yes, but how to know that upfront? I work in an industry where we know exactly the (material) cost of different failures. Semiconductors/chip designs, in an advanced, but not cutting edge technology. If all is ok, no redo costs; if I can fix a mishap with just metal routing: four months delay, little less then 1M$; if more extensive fail: at least six months and more then 1.5M$.

Tell me how much time I should spend upfront to verify everything before committing to fab? In hindsight every mishap would have been able to be found upfront if I would be aware it could happen. In real life we model what we can, verify what we expect, check coverage as far as possible; and then take a risk decision. Only when the chip comes back we know how good it is. And only then do we know if we better had spend more time upfront verifying.
They couldn't have known upfront.

All the critics pointing out the costs of risk taking are forgetting the benefits of risk taking, as proven by SpaceX's track record.

They also demonstrate how incapable the established players are of operating at the same level or keeping up.

The perversion of "Failure is not an option".

Shrug. The alternative is all to visible elsewhere...  Moving on.


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Offline steveleach

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #22 on: 04/24/2023 12:01 am »
Question is how much time this actually cost them.

Is the 1-2 months claim pure "Elon Time" or is there a logic behind it?
You'd have to pair that question with "how much delay would amore robust solution have added, and would it have fully mitigated the problems they saw on the 20th, or would they have needed another rebuild anyway?"

It might end up taking another 3-4 months before it is all repaired and ready for the next flight, sure. But adding the water-cooled plate and deluge system might have added 3 months before the first flight, and then it might have failed catastrophically anyway, and then needed another 3 months to fix again.

Offline meekGee

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #23 on: 04/24/2023 12:02 am »
Question is how much time this actually cost them.

Is the 1-2 months claim pure "Elon Time" or is there a logic behind it?

The truth is that they don’t know yet. So many systems that appear undamaged could have taken damage. It will likely take weeks to know the full extent of the damage.

Maybe Elon is using a “worst case scenario” (complete rebuild) when he made that estimate, but I highly doubt it. A complete rebuild would take longer.

“Elon time” statements usually assume that everything will go fine, so best case scenario.
My guess is they're figuring on replacing the table and fixing the mount legs and tank farm.  I hope the tower is ok.
« Last Edit: 04/24/2023 12:03 am by meekGee »
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Offline Lee Jay

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #24 on: 04/24/2023 12:04 am »
I fear that one of the things they learned from this is that some failures are more painful than others. …….. It's entirely possible that waiting for a deflector to be built would have been faster than launching without it.

Yes, but how to know that upfront? I work in an industry where we know exactly the (material) cost of different failures. Semiconductors/chip designs, in an advanced, but not cutting edge technology. If all is ok, no redo costs; if I can fix a mishap with just metal routing: four months delay, little less then 1M$; if more extensive fail: at least six months and more then 1.5M$.

Tell me how much time I should spend upfront to verify everything before committing to fab? In hindsight every mishap would have been able to be found upfront if I would be aware it could happen. In real life we model what we can, verify what we expect, check coverage as far as possible; and then take a risk decision. Only when the chip comes back we know how good it is. And only then do we know if we better had spend more time upfront verifying.
They couldn't have known upfront.

And yet, there's a post in this forum from 2020 predicting this outcome.

Online DigitalMan

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #25 on: 04/24/2023 12:08 am »
If you're going to attempt to build a clean-sheet simplest launch pad one of the requirements is still going to be managing the energy it is going to encounter.

That energy comes in a variety of forms.

We're probably never going to get to see the modeling of the environment that led SpaceX to think 1 launch might be managed. I don't think they were ignoring reality (something physics won't let slide) there was clearly a mistake somewhere along the line.

edit: I'll add, the process that led to the mistake is something they will no doubt be compelled to fix also.
« Last Edit: 04/24/2023 12:10 am by DigitalMan »

Offline Vultur

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #26 on: 04/24/2023 12:09 am »
Question is how much time this actually cost them.

Is the 1-2 months claim pure "Elon Time" or is there a logic behind it?
You'd have to pair that question with "how much delay would amore robust solution have added, and would it have fully mitigated the problems they saw on the 20th, or would they have needed another rebuild anyway?"

It might end up taking another 3-4 months before it is all repaired and ready for the next flight, sure. But adding the water-cooled plate and deluge system might have added 3 months before the first flight, and then it might have failed catastrophically anyway, and then needed another 3 months to fix again.

If it's 3-4 months they haven't lost much at all. F1 had a year between the first and second launch attempts, F9 was six months between launch 1 and 2.

Also, 3-4 months would be July or August, and if the improvements work they could probably launch quicker in the future: if they could get it down to 2 months afterwards they could still get 4 launches in 2023 (July-August, Sept-Oct, Nov-Dec), and even 5 might not be ruled out given how fast they build vehicles.

The real concern is if it's 7+ months (some people in the other thread are suggesting years...) and they only get 1, or 0, more launches in 2023 and so (being limited to 5/year) can only manage 6 or 7 by the end of 2024.
« Last Edit: 04/24/2023 12:10 am by Vultur »

Online matthewkantar

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #27 on: 04/24/2023 12:13 am »
And yet, there's a post in this forum from 2020 predicting this outcome.

Yeah, SpaceX ignored all the seasoned industry experts (and others) on this forum saying vertical stage landings are impossible, are uneconomical, etc. What did that get them?  Picking an example in hindsight is easy, and completely worthless.

While I'm at it, having a YouTube channel does not confer any credibility. Citing the YouTusual suspects is not compelling in my opinion.

Edited, spelling.
« Last Edit: 04/24/2023 01:02 pm by matthewkantar »

Offline Lars-J

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #28 on: 04/24/2023 12:13 am »
All the critics pointing out the costs of risk taking are forgetting the benefits of risk taking, as proven by SpaceX's track record.

They also demonstrate how incapable the established players are of operating at the same level or keeping up.

The perversion of "Failure is not an option".

Shrug. The alternative is all to visible elsewhere...  Moving on.

There’s risk and then there is risk.

They have many boosters and ships. They can launch them and experiment without massive risk. Launching B7/S24 seems like a reasonable risk to take.

The only have one launch pad/OLM. That is where one would imagine less risk taking should happen. This is where extra margin was needed to reduce (but not eliminate) risk. All the boosters in the world don’t mean much if you can’t launch or test them.

So don’t put up this false dilemma between SpaceX and regular aerospace. There are steps between them. And perhaps SpaceX didn’t really follow their own mantra enough with their single failure point.

Offline GmP

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #29 on: 04/24/2023 12:15 am »
Question is how much time this actually cost them.

Is the 1-2 months claim pure "Elon Time" or is there a logic behind it?

They were already working on the water cooled steel plates.
A: not launched scenario: wait two months to install the plates, launch.
A1: plates work, no damage to OLM no OLT, next launch in two month plus then 4-6 weeks?
A2: plates help, but not enough, need flame diverter also. Next launch 3-4 month to allow new to design flame diverter, maybe using water cooled steel plates?
B: since they did launch, and now know/realize what needs to be done: same 3-4 months to next launch as the flame diverter is the long pole: how to fit under the OLM? Only difference with A2 is the repair of all the damage. In my view, unless there is real structural damage, this fits in the same 3-4 months.
Overal not much difference in outcome towards next flight. Only with launch they have now data from the flight itself, that can be used for the next launch. How much of it is helpful data depends on the reason for the engines and other damage on the booster. If all issues seen were because of concrete blown up and no real lessons to learn about start up or throttle or vector control, then maybe not a lot of learning.


Offline Lars-J

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #30 on: 04/24/2023 12:23 am »
Question is how much time this actually cost them.

Is the 1-2 months claim pure "Elon Time" or is there a logic behind it?
You'd have to pair that question with "how much delay would amore robust solution have added, and would it have fully mitigated the problems they saw on the 20th, or would they have needed another rebuild anyway?"

It might end up taking another 3-4 months before it is all repaired and ready for the next flight, sure. But adding the water-cooled plate and deluge system might have added 3 months before the first flight, and then it might have failed catastrophically anyway, and then needed another 3 months to fix again.

Would it have fully mitigated the issue? Probably not. Would it have helped? Yes, very likely.

Part of my problem with the argument that a water cooled plate/diverter was not ready is that there really shouldn’t have been any wait for it. The Starbase pad has been in the works for years… Yet someone only managed to convince the boss very recently that such a system was a good idea. Why was it not in the works much earlier?

Offline meekGee

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #31 on: 04/24/2023 12:24 am »
All the critics pointing out the costs of risk taking are forgetting the benefits of risk taking, as proven by SpaceX's track record.

They also demonstrate how incapable the established players are of operating at the same level or keeping up.

The perversion of "Failure is not an option".

Shrug. The alternative is all to visible elsewhere...  Moving on.

There’s risk and then there is risk.

They have many boosters and ships. They can launch them and experiment without massive risk. Launching B7/S24 seems like a reasonable risk to take.

The only have one launch pad/OLM. That is where one would imagine less risk taking should happen. This is where extra margin was needed to reduce (but not eliminate) risk. All the boosters in the world don’t mean much if you can’t launch or test them.

So don’t put up this false dilemma between SpaceX and regular aerospace. There are steps between them. And perhaps SpaceX didn’t really follow their own mantra enough with their single failure point.
But you could have said that on many other risks they took over time with various setups, risking lots.of infrastructure. Amd those were outright wins.

And had they waited another 2 months, would the risk have gone to zero?  Of course not.

It's all levels of gray.

They'll now have a more advanced launch table, and it'll have the benefit of a more mature rocket, and other things they found out during this extravaganza.

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Offline GmP

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #32 on: 04/24/2023 12:28 am »
I fear that one of the things they learned from this is that some failures are more painful than others. …….. It's entirely possible that waiting for a deflector to be built would have been faster than launching without it.

Yes, but how to know that upfront? I work in an industry where we know exactly the (material) cost of different failures. Semiconductors/chip designs, in an advanced, but not cutting edge technology. If all is ok, no redo costs; if I can fix a mishap with just metal routing: four months delay, little less then 1M$; if more extensive fail: at least six months and more then 1.5M$.

Tell me how much time I should spend upfront to verify everything before committing to fab? In hindsight every mishap would have been able to be found upfront if I would be aware it could happen. In real life we model what we can, verify what we expect, check coverage as far as possible; and then take a risk decision. Only when the chip comes back we know how good it is. And only then do we know if we better had spend more time upfront verifying.
They couldn't have known upfront.

And yet, there's a post in this forum from 2020 predicting this outcome.

Yes. Going back to my own work: With every risk review and decision making there will be people who have a different opinion. We document those (not in fan forums, but in decision meeting minutes: FMEA style) to learn from. And sometimes, in hindsight, they are proven right. We underestimated the failure mode, or the impact of the fail on the end product.

If all people agree then there really is no risk decision reviews and meetings needed, correct?
In practice the best decision in (our) team meetings is a consensus that the rewards as predicted are worth the risks as known.
« Last Edit: 04/24/2023 12:30 am by GmP »

Offline Corvus Corax

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #33 on: 04/24/2023 12:41 am »
Question is how much time this actually cost them.

Is the 1-2 months claim pure "Elon Time" or is there a logic behind it?
You'd have to pair that question with "how much delay would amore robust solution have added, and would it have fully mitigated the problems they saw on the 20th, or would they have needed another rebuild anyway?"

It might end up taking another 3-4 months before it is all repaired and ready for the next flight, sure. But adding the water-cooled plate and deluge system might have added 3 months before the first flight, and then it might have failed catastrophically anyway, and then needed another 3 months to fix again.

Would it have fully mitigated the issue? Probably not. Would it have helped? Yes, very likely.

Part of my problem with the argument that a water cooled plate/diverter was not ready is that there really shouldn’t have been any wait for it. The Starbase pad has been in the works for years… Yet someone only managed to convince the boss very recently that such a system was a good idea. Why was it not in the works much earlier?

This.

It's astonishing to me that there must have been meetings that included any semblance of a thought that they could get away with such an underbuilt launchpad. Assuming there was some kind of a negotiation process going on behind the scenes, I can't imagine any scenario where there would be any "pros" to launching when they did. It makes no sense.

Offline Redclaws

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #34 on: 04/24/2023 01:37 am »
Question is how much time this actually cost them.

Is the 1-2 months claim pure "Elon Time" or is there a logic behind it?
You'd have to pair that question with "how much delay would amore robust solution have added, and would it have fully mitigated the problems they saw on the 20th, or would they have needed another rebuild anyway?"

It might end up taking another 3-4 months before it is all repaired and ready for the next flight, sure. But adding the water-cooled plate and deluge system might have added 3 months before the first flight, and then it might have failed catastrophically anyway, and then needed another 3 months to fix again.

Would it have fully mitigated the issue? Probably not. Would it have helped? Yes, very likely.

Part of my problem with the argument that a water cooled plate/diverter was not ready is that there really shouldn’t have been any wait for it. The Starbase pad has been in the works for years… Yet someone only managed to convince the boss very recently that such a system was a good idea. Why was it not in the works much earlier?

This.

It's astonishing to me that there must have been meetings that included any semblance of a thought that they could get away with such an underbuilt launchpad. Assuming there was some kind of a negotiation process going on behind the scenes, I can't imagine any scenario where there would be any "pros" to launching when they did. It makes no sense.

I mean, there are always pros to launching early.  You learn stuff earlier.  It’s just whether the cons outweigh the pros.  It does seem to have been wildly underbuilt.

Offline meekGee

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #35 on: 04/24/2023 02:31 am »
Question is how much time this actually cost them.

Is the 1-2 months claim pure "Elon Time" or is there a logic behind it?
You'd have to pair that question with "how much delay would amore robust solution have added, and would it have fully mitigated the problems they saw on the 20th, or would they have needed another rebuild anyway?"

It might end up taking another 3-4 months before it is all repaired and ready for the next flight, sure. But adding the water-cooled plate and deluge system might have added 3 months before the first flight, and then it might have failed catastrophically anyway, and then needed another 3 months to fix again.

Would it have fully mitigated the issue? Probably not. Would it have helped? Yes, very likely.

Part of my problem with the argument that a water cooled plate/diverter was not ready is that there really shouldn’t have been any wait for it. The Starbase pad has been in the works for years… Yet someone only managed to convince the boss very recently that such a system was a good idea. Why was it not in the works much earlier?

This.

It's astonishing to me that there must have been meetings that included any semblance of a thought that they could get away with such an underbuilt launchpad. Assuming there was some kind of a negotiation process going on behind the scenes, I can't imagine any scenario where there would be any "pros" to launching when they did. It makes no sense.
They happened right after the meeting where the same clueless people suggested you can build rockets using shipbuilding techniques.  The humanity.

You can't try absolutely new ways of doing things and be successful 100% of the time. Sometimes you'll find out you went a bit too far, simplified a bit too much.

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Offline edzieba

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #36 on: 04/24/2023 10:47 am »
One of the possible - and evaluated extensively as part of the EA process - outcomes was for the stack to RUD on the pad, fully fuelled. That would have a been a much bigger boom than the flying concrete chunks, so the pad damage is likely below the worst-case-scenario considered and accepted as the risk of a first launch. The tank farm is dented but intact (no massive cryogen releases, no LCH4 leaks leading to explosions, etc), the tower did not fall over, the chopstick lift cables did not snap, the QD arm was not blown off, the launch table did mot fall over, the booster QD was not blown off, etc).

It was a surprise that the relatively thin Fondag layer over dirt held up acceptably - some surface spalling but otherwise intact - to the 50% thrust static fire but not to the 90% thrust launch, but it does mean the threshhold between "concrete spalls but remains intact" and "concrete shatters and allows exhaust flow to dig out dirt beneath pad" is somewhere between those two values. Which also means there is very likely a combination of thicker concrete and a more resilient top layer that will hold up to a 100% thrust firing.
SpaceX appear to be betting that a watercooled steel sheet and some amount of deeper concrete under it (there's already a nice hold dug to fill...) will move that threshhold back above the expected thrust range for Super Heavy.

A pyramid-type rollable flame diverter (or more likely, several segmented sections of a diverter, to fit through the legs) would keep the flat surface to allow for access to the mount, but has the issue of connecting and disconnecting the very-high-flow water supply to the segments, unlike a flat plate where the connections can be fixed and armoured in caissons below the pad, as already successfully protected the fixed plumbing to the OLM.

Offline lawlessl

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #37 on: 04/24/2023 11:00 am »
Yes, but how to know that upfront? I work in an industry where we know exactly the (material) cost of different failures. Semiconductors/chip designs, in an advanced, but not cutting edge technology.

And yet, there's a post in this forum from 2020 predicting this outcome.

My first career was designing silicon chips also. I was amused recently when ebay sold one of the chips from back then.

Back then we were not safe in a fully modelled world. Imagine a time before Synopsys even existed. Today, in the same way we do not model the next unknowns. I was part of the ASIC revolution that brought chip design, and especially microprocessors to the masses. Designing a chip today is not the same as designing a new revolution in rockets. The ASIC revolution was to remove the unknowns.

The man behind it once came to talk with a small group of engineers. He told us about his early days and when he first saw metal migration. They watched it happen under a microscope. He then built a design system to never let it happen again, so people expert in their applications did not need to be expert in chip engineering.

I also do not believe this was predicted at all. Yes, there might have been predictions of erosion etc. but this was not caused by erosion or spalling of surfaces. This was nearer to earthquake and sea wall engineering.

We do, and we learn.
« Last Edit: 04/24/2023 11:05 am by lawlessl »

Offline Cheapchips

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #38 on: 04/24/2023 11:11 am »
It was a surprise that the relatively thin Fondag layer over dirt held up acceptably - some surface spalling but otherwise intact - to the 50% thrust static fire but not to the 90% thrust launch, but it does mean the threshhold between "concrete spalls but remains intact" and "concrete shatters and allows exhaust flow to dig out dirt beneath pad" is somewhere between those two values. Which also means there is very likely a combination of thicker concrete and a more resilient top layer that will hold up to a 100% thrust firing.
SpaceX appear to be betting that a watercooled steel sheet and some amount of deeper concrete under it (there's already a nice hold dug to fill...) will move that threshhold back above the expected thrust range for Super Heavy.

I think that's something that was on my mind.  When the flat floor under the mount doesn't explode, the exhaust seems to be directed quite neatly through all six openings.  You can see even on the 31 engine static fire, the exhaust doesn't come above the table.  I'd be surprised if we see anything other than the steel water cooled plate on the next attempt, whenever that will be.

Offline lawlessl

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Re: Starship Launch Mount / Pad / Table Discussion
« Reply #39 on: 04/24/2023 11:26 am »
You can't try absolutely new ways of doing things and be successful 100% of the time. Sometimes you'll find out you went a bit too far, simplified a bit too much.

Or you can run into an unknown.
Some one asked for a design for a floor to withstand a force of X. A civil engineer did the calculations. A swamp expert did the pile calculations. The answer had a huge margin of safety. No one thought again about it.

There were no sea wall or earthquake experts, with rocket thrust vibration appreciation, that had coffee on that day at SpaceX and could have over heard the design review. Even if that person existed at all in the world.

They ran into a knowledge void. The world has to do that to learn. The most damaging part is the wide communication that this is a disaster. This is learning. Some bent metal is learning.

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