totm nov 2023 SpaceX Discussion Thread

[kerbiloid]

1 hour ago, wumpus said:

I'm pretty sure that the higher (and therefore more volume "consumed") the satellite is, the less likely it is to hit anything.

The higher it is, the slower it moves. So, the tax should be per 1/( turn duration). Like km/s * cross-section area * coefficient of average saats amount per volume

Edited September 4, 2019 by kerbiloid

[tater]

 

 

[CatastrophicFailure]

Ahah! Right off the bat, we see the new landing leg/fin design. They shall, indeed, be separate parts. And horizontal processing too, at least to some degree. Gonna be a big TEL. 

[Rakaydos]

18 minutes ago, CatastrophicFailure said:

Ahah! Right off the bat, we see the new landing leg/fin design. They shall, indeed, be separate parts. And horizontal processing too, at least to some degree. Gonna be a big TEL. 

are those legs? Or are those the orbital refueling feeds?

[tater]

I’d take the renders with a grain (or fistful) is salt.

[CatastrophicFailure]

8 minutes ago, Rakaydos said:

are those legs? Or are those the orbital refueling feeds?

I can’t imagine they’d have something so delicate sticking out in the airstream like that. @tater is quite right, best take anything with a nice big salt lick, but changes to the gear/fin design have been popping up a lot in the scuttlebutt lately.  

[tater]

 

[Wjolcz]

So, at least in BC, it will get horizontal at some point after all. I thought it would be vertical the whole time and then transported much the same way to the pad.

Now, I don't think they will transport it like that because that would require some sort of internal structure extending all the way to the nose region, but maybe they will have something like that? It needs to be lifted by cranes somehow after all.

[NSEP]

If those stubby legs are in the new design, that must mean that there are no more fin-legs, hmmm i wonder what the new fin structure will look like now. Maybe it will be more like the Space Shuttle/IAC 2017 design?

[Wjolcz]

21 minutes ago, NSEP said:

If those stubby legs are in the new design, that must mean that there are no more fin-legs, hmmm i wonder what the new fin structure will look like now. Maybe it will be more like the Space Shuttle/IAC 2017 design?

Maybe it's both but with leg structure sticking out on the ship's hull.

Edit: 2 problems I see with the fins acting as legs is the problem with protecting the hinges during movement. The hinge part would either have to be covered in shielding material or the shield material/structure would have to somehow move in and out to cover the hinge. The second problem is the twisting of fins on the ground we've discussed before. Adding three more legs in the middle is a nice way to counteract that.

Edited September 6, 2019 by Wjolcz

[Technical Ben]

48 minutes ago, Wjolcz said:

Maybe it's both but with leg structure sticking out on the ship's hull.

Edit: 2 problems I see with the fins acting as legs is the problem with protecting the hinges during movement. The hinge part would either have to be covered in shielding material or the shield material/structure would have to somehow move in and out to cover the hinge. The second problem is the twisting of fins on the ground we've discussed before. Adding three more legs in the middle is a nice way to counteract that.

This old pic shows no folding:

But instead pop out legs.

 

[edit]

But tweets say it's an old design.

Edited September 6, 2019 by Technical Ben

[kerbiloid]

Also this picture shows another Starship and a group of tanks inside the radius of regolith shrapnel.

[Wjolcz]

1 hour ago, Technical Ben said:

This old pic shows no folding:

But instead pop out legs.

 

[edit]

But tweets say it's an old design.

That's why I think it's combined. There could be three legs like on this render + three fins like on the more recent design.

Edit: either that or there are 2 fins instead of three to save weight. But then those fins would be kind of useless or even liability on the ground.

Edited September 6, 2019 by Wjolcz

[tater]

3 hours ago, Wjolcz said:

That's why I think it's combined. There could be three legs like on this render + three fins like on the more recent design.

Edit: either that or there are 2 fins instead of three to save weight. But then those fins would be kind of useless or even liability on the ground.

The render shown has 4 legs.

[RealKerbal3x]

With the fin-legs, it was a single point of catastrophic failure. A failure of the actuating hinges on the lower two fins would mean loss of control during reentry, and a landing failure. Personally, I'm happy to see the fins be liberated from the role of supporting the ship during landing, because it makes Starship a little safer.

Edited September 6, 2019 by RealKerbal3x

[mikegarrison]

40 minutes ago, RealKerbal3x said:

With the fin-legs, it was a single point of catastrophic failure. A failure of the actuating hinges on the lower two fins would mean loss of control during reentry, and a landing failure. Personally, I'm happy to see the fins be liberated from the role of supporting the ship during landing, because it makes Starship a little safer.

I still fail to understand this line of thinking. If the legs fail (whether they are part of the fin or not) it will be a Bad Thing (TM). If the control surfaces fail (whether they are part of the legs or not) it will be a Bad Thing. Separating them may have other advantages, but it does not seem to avoid any failure modes.

[RealKerbal3x]

3 minutes ago, mikegarrison said:

I still fail to understand this line of thinking. If the legs fail (whether they are part of the fin or not) it will be a Bad Thing (TM). If the control surfaces fail (whether they are part of the legs or not) it will be a Bad Thing. Separating them may have other advantages, but it does not seem to avoid any failure modes.

Fair enough, it'll be very bad if they fail, regardless of whether they're separate systems or not. But keeping them separate still reduces the chance that two critical systems will fail at once.

[mikegarrison]

2 minutes ago, RealKerbal3x said:

Fair enough, it'll be very bad if they fail, regardless of whether they're separate systems or not. But keeping them separate still reduces the chance that two critical systems will fail at once.

Yes, I guess that is true.

[CatastrophicFailure]

15 minutes ago, mikegarrison said:

I still fail to understand this line of thinking. If the legs fail (whether they are part of the fin or not) it will be a Bad Thing (TM). If the control surfaces fail (whether they are part of the legs or not) it will be a Bad Thing. Separating them may have other advantages, but it does not seem to avoid any failure modes.

If you look real close at some renders, it looks like there’s actually eight legs. So, if accurate, that would give some redundancy. But, Musk said it’s not accurate, so for all we know they’ve gone back to the “Giant Bouncy House” recovery model. 

[tater]

I counted 21 unmounted rings not paying all that much attention.

[magnemoe]

On 9/6/2019 at 1:24 AM, tater said:

I’d take the renders with a grain (or fistful) is salt.

An  salt mine below the death sea. 
Separate legs makes some sense. Fins is an backup, horizontal will not work well or manned on rapid turnaround. 
You need serious cleaning to get rid of junk in freefalll. Also an issue on cargo, yes you can get it to work but its an mess. 
 

[CatastrophicFailure]

 

[tater]

 

[smallstars]

On 5/24/2018 at 3:34 PM, NSEP said:

There is a better alternative than making a specific centrifuge module. How about we make the BFR itself the centrifuge. They could connect 2 BFR's and connected them via tether to create artificial gravity.

Like this:

The two BFR's could dock and deploy the tether after the transfer burn to Mars, or whatever destination they could be going to. They would simply spin it around to create artificial gravity. No expensive gizmos required other than a special port for the tethers.

This is just a concept however, so far there are no plans for artificial gravity yet for the BFR, and its unlikely it will be favourable over treadmills.

Hey check out this artificial gravity solution I came up with: https://www.youtube.com/watch?v=3CRiJTJikjk

Edited September 8, 2019 by smallstars

[tater]

https://twitter.com/FarryFaz/status/1170535429499736069

 

Edited September 8, 2019 by tater