Author Topic: Starship Launch Mount / Pad / Table Discussion  (Read 262748 times)

Offline BramV

  • Member
  • Posts: 1
  • Netherlands
  • Liked: 0
  • Likes Given: 1
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #40 on: 04/24/2023 11:59 am »
Hi, Does anyone know how deep the 6 pillars form the orbital launch mount go into the ground? Many people seem to assume the pad is a total loss, but I doubt that.
If these 6 pillars go much deeper than the crater that was created, it could still be not 'gronkt'
So anyone know a good estimation of the depth these pillars go?

Offline SteveU

  • Full Member
  • ***
  • Posts: 383
  • New England
  • Liked: 438
  • Likes Given: 2391
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #41 on: 04/24/2023 12:08 pm »
The numbers being thrown around are 45-55 meters
"Better a diamond with a flaw than a pebble without." - Confucius

Offline lawlessl

  • Full Member
  • *
  • Posts: 119
  • UK
  • Liked: 125
  • Likes Given: 99
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #42 on: 04/24/2023 01:08 pm »
I mean, there are always pros to launching early.  You learn stuff earlier.  Its just whether the cons outweigh the pros.  It does seem to have been wildly underbuilt.

A rocket lifted off far too slowly, while the pad was experiencing a shrapnel barrage like a war, while the foundations were being attacked like a huge storm removing a sea wall.

And afterwards it is still standing and 99% still there.

Underbuilt!

It had one design issue. I am just glad they designed it so that they could not abort take off. The rocket showed itself, in my opinion, to be far too robust. Imagine if anyone had suggested a test strategy of firing missiles into the engine area and then doing gymnastics at 35km. They had to blow it up in the end with explosives.

Offline AU1.52

  • Full Member
  • ****
  • Posts: 656
  • Life is like riding a bicycle - Einstein
  • Ohio, USA, AU1
  • Liked: 669
  • Likes Given: 719
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #43 on: 04/24/2023 01:18 pm »
Does any one have thoughts about the OLM door that got blown out? The door looked petty mangled. Over pressure inside the newly enclosed space from rocket exhaust entering the OLM from the inner part of the ring? I wonder what the inside look like now.

Offline Corvus Corax

  • Full Member
  • *
  • Posts: 176
  • New England
  • Liked: 310
  • Likes Given: 147
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #44 on: 04/24/2023 01:25 pm »
Does any one have thoughts about the OLM door that got blown out? The door looked petty mangled. Over pressure inside the newly enclosed space from rocket exhaust entering the OLM from the inner part of the ring? I wonder what the inside look like now.

If you look next to the door frame, you can see large scratches. I imagine that concrete debris struck the frame and broke the welds on the door. Thrust then peeled the door away.

Offline lawlessl

  • Full Member
  • *
  • Posts: 119
  • UK
  • Liked: 125
  • Likes Given: 99
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #45 on: 04/24/2023 01:41 pm »
Does any one have thoughts about the OLM door that got blown out?

I assume that is the door in Starship Gazers tweet. It seems to be been bent in half and the bottom edge severely crushed. I assume the hinges were on the left. This could be from landing, but it also could be from attack from below by concrete shearing it off. As it is right next to a large piece of concrete I suggest it was going the same way.

The damage does not look like pressure from inside.

Offline baking

  • Full Member
  • ****
  • Posts: 666
  • Boston
  • Liked: 575
  • Likes Given: 129
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #46 on: 04/24/2023 01:49 pm »
You can look back in the launch site discussion from June 2020 and see pictures of the rebar cages they lowered into the holes.

Offline AU1.52

  • Full Member
  • ****
  • Posts: 656
  • Life is like riding a bicycle - Einstein
  • Ohio, USA, AU1
  • Liked: 669
  • Likes Given: 719
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #47 on: 04/24/2023 02:19 pm »
Does any one have thoughts about the OLM door that got blown out?

I assume that is the door in Starship Gazers tweet. It seems to be been bent in half and the bottom edge severely crushed. I assume the hinges were on the left. This could be from landing, but it also could be from attack from below by concrete shearing it off. As it is right next to a large piece of concrete I suggest it was going the same way.

The damage does not look like pressure from inside.


That would be a very good thing!

Offline SDSmith

  • Danny Smith
  • Full Member
  • **
  • Posts: 211
  • Sugar Hill
  • Liked: 185
  • Likes Given: 431
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #48 on: 04/24/2023 02:27 pm »
Does any one have thoughts about the OLM door that got blown out?

I assume that is the door in Starship Gazers tweet. It seems to be been bent in half and the bottom edge severely crushed. I assume the hinges were on the left. This could be from landing, but it also could be from attack from below by concrete shearing it off. As it is right next to a large piece of concrete I suggest it was going the same way.

The damage does not look like pressure from inside.


That would be a very good thing!
There is a second door on the mount with no visible damage.

Offline whitelancer64

Re: Starship Launch Mount / Pad / Table Discussion
« Reply #49 on: 04/24/2023 02:30 pm »
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.

An engineer designing concrete for a launch pad that didn't take into account vibrations and etc. from a launch would be a TERRIBLE engineer.

YES. SpaceX has engineers that have designed and built launch pads and would take into account all the forces that pad would experience during a launch. It's mind-boggling to think they have such expertise on hand and they decided NOT use it to design the Boca Chica launch pad.

There's no knowledge void involved here. Elon Musk, in his hubris, wanted a flat launch pad with no diverter.

This was a disaster, and one of Elon Musk's making. It was easily avoidable.
"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to." - Elon Musk
"There are lies, damned lies, and launch schedules." - Larry J

Offline edzieba

  • Virtual Realist
  • Senior Member
  • *****
  • Posts: 5988
  • United Kingdom
  • Liked: 9162
  • Likes Given: 38
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #50 on: 04/24/2023 02:37 pm »
There's no knowledge void involved here.
I'd be interested to see the standard calculator for concrete pad pour depth below Nova-C8-class supersonic hot-gas streams. Would that be an ASTM standard, because it's not covered in the ACI manual of concrete practice!

Offline whitelancer64

Re: Starship Launch Mount / Pad / Table Discussion
« Reply #51 on: 04/24/2023 02:48 pm »
There's no knowledge void involved here.
I'd be interested to see the standard calculator for concrete pad pour depth below Nova-C8-class supersonic hot-gas streams. Would that be an ASTM standard, because it's not covered in the ACI manual of concrete practice!

How many launch pads has SpaceX worked on / built / rebuilt over the years?

You really don't think that they have an engineering team capable of doing such calculations?
"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to." - Elon Musk
"There are lies, damned lies, and launch schedules." - Larry J

Online DanClemmensen

  • Senior Member
  • *****
  • Posts: 5354
  • Earth (currently)
  • Liked: 4196
  • Likes Given: 1693
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #52 on: 04/24/2023 02:56 pm »
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.
I suspect that in addition to the flat steel plate directly under the pad we will see steel or Fondag extending out a lot further in all directions, increased height of the angled diverter walls, and extension of those walls into a nearly full circle. In effect the whole site would become a very large bowl-shaped flame diverter.

Offline EL_DIABLO

  • Full Member
  • *
  • Posts: 180
  • Liked: 143
  • Likes Given: 157
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #53 on: 04/24/2023 03:02 pm »
On the RGV livestream they stated 140 feet.

Offline spacenut

  • Senior Member
  • *****
  • Posts: 5180
  • East Alabama
  • Liked: 2587
  • Likes Given: 2895
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #54 on: 04/24/2023 03:31 pm »
Someone made a comment about digging a canal from the ocean or shipping canal to fill a large bowl area under the pad with water.  This was suggested in the 1960's with the large Rombus rocket.   Otherwise building an offshore platform off Boca Chica. 

It looks like the existing pad will need a lot of work.  Flame trench or diverter, water suppression, etc.  Same will have to happen at Cape Kennedy facility. 

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39254
  • Minnesota
  • Liked: 25206
  • Likes Given: 12104
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #55 on: 04/24/2023 03:36 pm »
Dunno why youd want to add saltwater to the mix. Water cooled flame diverter, maybe with deluge, will work. They already had the pieces for it at Boca Chica 2 weeks before launch.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Spindog

  • Full Member
  • *
  • Posts: 166
  • US
  • Liked: 220
  • Likes Given: 2
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #56 on: 04/24/2023 03:37 pm »
The canal idea would require a really large body of water. Like having the launch mount standing in the center of a lake. A deep lake. With anything like a small pond, starship would quickly just blow all the water out and start scouring the basin.

Offline lawlessl

  • Full Member
  • *
  • Posts: 119
  • UK
  • Liked: 125
  • Likes Given: 99
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #57 on: 04/24/2023 03:45 pm »
In effect the whole site would become a very large bowl-shaped flame diverter.

That is exactly the problem. It is wrong to create a bowl shape. Debris should be constrained along the ground. I was initially surprised that the sloping wall by the tank farm did not have a wave reversing top, as seen on sea walls. If a high velocity item hits the wall it should be encouraged to travel up the wall and then get returned. In the same manner as a pelton wheel.

Maybe they wanted it to bounce straight up and not go back into the mix. The lower wall is vertical as a dead stop for items. They obviously designed it expecting horizontal debris.

I doubt any of the damage was caused by any material that hit that wall first. It seems from the coverage there is no significant debris or damage in that area. The wall took no part as it all went upwards due to the "hole" under the OLM.

Offline Cheapchips

  • Full Member
  • ****
  • Posts: 1029
  • UK
  • Liked: 854
  • Likes Given: 1923
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #58 on: 04/24/2023 04:01 pm »
Has anyone mocked up what the 'flame diverter' pieces actually create yet? I haven't seen any suggestions so far.

I'm curious as to whether it will just be a flat cooled floor or have more of a shape to it.  It certainly doesn't look like they're going with the traditional options of a curved ramp, triangle ramp or central pyramid, at least from the pieces on display at present.

(although I should declare that I'm terrible at geometry puzzles)

Offline Coastal Ron

  • Senior Member
  • *****
  • Posts: 8831
  • I live... along the coast
  • Liked: 10171
  • Likes Given: 11899
Re: Starship Launch Mount / Pad / Table Discussion
« Reply #59 on: 04/24/2023 04:17 pm »
In effect the whole site would become a very large bowl-shaped flame diverter.

That is exactly the problem. It is wrong to create a bowl shape. Debris should be constrained along the ground.

Assuming the new water-cooled flame diverter works, and doesn't shed parts, what debris would there be during a launch except for the dust, dirt, and stuff dropped on the ground around the pad before launch? It should be just exhaust gasses.

Though SpaceX might want to perform a thorough pad area cleaning before each launch (like the FOD walk on aircraft carriers) to ensure nothing significant is available to cause damage.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Tags: Table 
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1