totm nov 2023 SpaceX Discussion Thread

[tater]

Photoshopped by RGV with 8 segments stacked:

 

[YNM]

38 minutes ago, tater said:

Photoshopped by RGV with 8 segments stacked:

And that's just the crane. Holy cow.

Does it mean the big mobile crane would be re-arranged again later ? Or are they going to start to use tower cranes on the tower itself to do the last few pieces ?

Also given the hurricanes I guess better leave it as open-web structure...

[Beccab]

1 minute ago, YNM said:

Does it mean the big mobile crane would be re-arranged again later ?

Biggest crane (LR11350?) will receive more sections soon enough to complete the construction if I understand correctly

[tater]

9 minutes ago, YNM said:

Does it mean the big mobile crane would be re-arranged again later ? Or are they going to start to use tower cranes on the tower itself to do the last few pieces ?

They can add segments to the crane. It is configured to also lift the very heavy "launch table" that sits on the actual pad.

[YNM]

24 minutes ago, tater said:

It is configured to also lift the very heavy "launch table" that sits on the actual pad.

Right, so now they're going with the shorter boom so they could lift heavier stuff.

Also those concrete pump cranes have reached their limit as well. I guess on the final segments the big one is going to see more action than just stacking it up...

Edited May 28, 2021 by YNM

[SpaceFace545]

2 hours ago, YNM said:

Also given the hurricanes I guess better leave it as open-web structure...

I bet they’ll leave it as that mesh stuff on the falcon 9 tower

[Nothalogh]

9 hours ago, sh1pman said:

Schrödinger‘s orbit.

It exists in superposition of both orbit and not, until the kinetic heating starts

[YNM]

1 hour ago, SpaceFace545 said:

I bet they’ll leave it as that mesh stuff on the falcon 9 tower

Since that tower used to be an open structure in the times of Apollo and Shuttle as well I guess it makes sense. They just put mesh over it, doesn't really change the openness I imagine.

[Elthy]

Any structure that can survive a Superheavy launch with a few meters distance propably doesnt have to worry about hurricanes...

Edited May 29, 2021 by Elthy

[Flying dutchman]

A thought Just ocurred to me.. starship can land on a single engine, but would it be able to do the flip on only one engine if the flip was done more gently and at a higher altitude?

[Beccab]

Just now, Flying dutchman said:

A thought Just ocurred to me.. starship can land on a single engine, but would it be able to do the flip on only one engine if the flip was done more gently and at a higher altitude?

With hot gas thrusters as RCS when those arrive l'd say it shouldn't be hard to do

[snkiz]

46 minutes ago, Flying dutchman said:

A thought Just ocurred to me.. starship can land on a single engine, but would it be able to do the flip on only one engine if the flip was done more gently and at a higher altitude?

The first one did that, would have worked if it hadn't started running engine rich.

[RCgothic]

46 minutes ago, Flying dutchman said:

A thought Just ocurred to me.. starship can land on a single engine, but would it be able to do the flip on only one engine if the flip was done more gently and at a higher altitude?

With a significant mass penalty due to increased gravity losses, yes. Which is why they don't.

With hot gas thrusters they may be able to be even more aggressive.

[YNM]

2 hours ago, Elthy said:

Any structure that can survive a Superheavy launch with a few meters distance propably doesnt have to worry about hurricanes...

Wouldn't they have like trenches, blast pads etc. ? Also probably not quite a few meters, more like ten meters.

19 hours ago, tater said:

This thing could be functional in a few weeks.

It usually takes about a week for concrete to properly solidify so from the final topping add a week or two. They also still need to modify the crane but that can be a 1/2 day job if they have enough workers and shift.

[Flying dutchman]

56 minutes ago, RCgothic said:

With a significant mass penalty due to increased gravity losses, yes. Which is why they don't.

With hot gas thrusters they may be able to be even more aggressive.

i know, i meant as a redundancy when the other engines are broken.

sn9 did the last half of the flip on a single engine after beginning the flip on two, then it couldn't counteract the rotation given by the two engine start of the flip. but if the flip was started on just one, would it have enough lever to be able to overcome aero forces in order to change it's orientation?

 

without the hot gas thrusters  which the current generation of starships doesn't have. i think the chances of sn16, 17 flying are pretty slim but it's just a hypothetical question.

59 minutes ago, snkiz said:

The first one did that, would have worked if it hadn't started running engine rich.

i'm pretty sure sn8 did the flip on two engines but shortly after one quit completely while the other one started running oxygen (and also engine) rich.

Edited May 29, 2021 by Flying dutchman

[tater]

[JoeSchmuckatelli]

17 hours ago, YNM said:

Also given the hurricanes I guess better leave it as open-web structure...

IIRC - cylindrical would be better.

 

 

[RCgothic]

2 hours ago, Flying dutchman said:

i know, i meant as a redundancy when the other engines are broken.

sn9 did the last half of the flip on a single engine after beginning the flip on two, then it couldn't counteract the rotation given by the two engine start of the flip. but if the flip was started on just one, would it have enough lever to be able to overcome aero forces in order to change it's orientation?

 

without the hot gas thrusters  which the current generation of starships doesn't have. i think the chances of sn16, 17 flying are pretty slim but it's just a hypothetical question.

i'm pretty sure sn8 did the flip on two engines but shortly after one quit completely while the other one started running oxygen (and also engine) rich.

By the time they find out they can't get 2 of 3 engines to start, it'll be too late to do a one engine flip and even if it isn't they won't be carrying the extra fuel required.

11 minutes ago, JoeSchmuckatelli said:

IIRC - cylindrical would be better.

 

 

I believe cylinders experience more turbulence than shapes with sharper discontinuities because the vortex shedding from a cylinder is more irregular. And an open structure limits the pressure differential across the panels which help prevent the panels getting blown out. It's why skyscrapers are very rarely pure cylinders.

Edited May 29, 2021 by RCgothic

[kerbiloid]

22 minutes ago, JoeSchmuckatelli said:

18 hours ago, YNM said:

Also given the hurricanes I guess better leave it as open-web structure...

IIRC - cylindrical would be better.

Pyramids.

Or cones.

Or old Germany shelters.
 

Spoiler

 

[JoeSchmuckatelli]

I saw one of those in a park in Vienna.  Disturbing reminder of darker times. 

[YNM]

1 hour ago, JoeSchmuckatelli said:

IIRC - cylindrical would be better.

Cylinders are only better since it has uniform strength and cross-section in all directions. Though rarely does tall buildings are made as cylinders, mostly due to footprint and available land, and to a small part for aesthetics, but also because since you'd make the structure out of elements smaller than the whole cross-section anyway the extra hassle required isn't of any particular advantage. With the exception of slip-forming the tower (like you would with chimneys or cooling towers, or in one case a test lift shaft), if you're doing steel truss / braced structures then triangular or rectangular is easier to deal with.

Now the individual elements are a different story - cylinders esp. steel cylinders have very good properties and are often used regardless of the shape of the building. The launch pad have cylindrical slanted columns.

Edited May 29, 2021 by YNM

[tater]

The Gulf coast has long experience with hurricanes, I'm not concerned.

[kerbiloid]

It's a shame that they are underestimating those German shelters (aka "Winkelturm").

Look at them.

1. Streamlined like a rocket. Streamlined as a tower.
2. Wide skirt to contain 30+ engines.
3. Looks Is much more stable when stands on ground than a cylinder.
4. Depending on size and material, can be both a rocket, a VAB, a lunar habitat, a Martian ISRU plant.
5. The dimensions are comparable.

Spoiler

6. Much more stable on reentry and aerobraking.. In any orientation.
7. Due to the low CoM can flip easier than Starship.

That's how a proper Sternenschiff Starship would look like.

And on-ground structures.

[JoeSchmuckatelli]

35 minutes ago, kerbiloid said:

It's a shame that they are underestimating those German shelters (aka "Winkelturm").

Look at them.

1. Streamlined like a rocket. Streamlined as a tower.
2. Wide skirt to contain 30+ engines.
3. Looks Is much more stable when stands on ground than a cylinder.
4. Depending on size and material, can be both a rocket, a VAB, a lunar habitat, a Martian ISRU plant.
5. The dimensions are comparable.

  Hide contents

6. Much more stable on reentry and aerobraking.. In any orientation.
7. Due to the low CoM can flip easier than Starship.

That's how a proper Sternenschiff Starship would look like.

And on-ground structures.

Certainly solves the landing legs issue 

Edit - although now that I think about drag... Perfect yard dart shape 

Edited May 29, 2021 by JoeSchmuckatelli

[CatastrophicFailure]