Skylon

SpaceX Discussion Thread

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1 minute ago, Xd the great said:

Or they can have a leg mounted, offset to the fins.

What do you mean? If the fins have legs attached, that would mean that they would have to bear the load of the craft sitting on the ground, so they would need to be more strengthened that how this looks:

View image on Twitter

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16 minutes ago, RealKerbal3x said:

It'll be interesting to see what the landing legs look like now. The finlegs do give quite a wide base, which increases the angle required for the ship to tip over, as I demonstrate with this diagram:

It needs stilettoes, to stick into ground.

Upd.
Or a single spike, like darts.

Edited by kerbiloid

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Just now, kerbiloid said:

It needs stilettoes, to stick into ground.

*like*

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I'm guessing they have purpose built legs. The fins could well be 180 degrees apart (we'll know for sure very soon), in which case they could have 4 legs that pop out to a wide spread .

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It's really hard to tell whether the fin currently being mounted will articulate or if it has a flap on the base or edge that articulates instead.

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1 hour ago, RealKerbal3x said:

It'll be interesting to see what the landing legs look like now. The finlegs do give quite a wide base, which increases the angle required for the ship to tip over, as I demonstrate with this diagram:

Dw4nyU6.jpg

(Note that I approximated the COM location and total fin diameter).

If the legs are now simply struts sticking out from the main body, that'll make the ship more liable to tipping.

Good point, note that the new fin are not angled backward, in fact they are angled forward an bit, its also longer. 
Benefit of separate fins and legs is that you don't get force on the fin in upward direction then landing, they only have to handle the aerodynamic. 
Downside is extra weight also one of the legs has to be in the reentry heat.
However the leg on the movable fins would also face reentry heat and the extractor mechanism for the leg facing reentry heat would be protected by the leg assuming they build the legs mostly like the falcon 9 legs. 
Other option is legs stored in the engine compartment, but this will limit the base width down to not much more than 9 meter unless they make an complex system who eat up space down there. 

 

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They just put the top bit of the nosecone onto that one replacement nosecone ring! On its own maybe that isn't as exciting as the fins, but the fact that this is all happening on the SAME DAY is incredible- they are really picking up pace!

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Just now, tater said:

 

Wow.

What is that monolith thing with a screen? Did they build the whole thing for the presentation or is it some sort of clever stream editing?

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The idea in the above render is that the small ends articulate, and the rest is fixed. They would need smaller actuators if this was the case.

His legs are based on that set of crappy SpaceX renders for the environmental report I think.

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28 minutes ago, tater said:

 

*Like* That would certainly explain Elon's mysterious "dragon wings" tweet... and look really cool!

 

I mean, not 100% sure there are fins on the end like this, but it would make sense.

 

The jokes about Starship slowly evolving into the Shuttle will only get worse from here, though... lol

27 minutes ago, Wjolcz said:

Wow.

What is that monolith thing with a screen? Did they build the whole thing for the presentation or is it some sort of clever stream editing?

Stream editing. Just some picture-in-picture fun.

Edited by ThatGuyWithALongUsername

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15 minutes ago, tater said:

The idea in the above render is that the small ends articulate, and the rest is fixed. They would need smaller actuators if this was the case.

His legs are based on that set of crappy SpaceX renders for the environmental report I think.

If only the ends articulate, then what would the big space between the body and the fin be there for? I think that a lot of people were theorizing that it was for the fin actuator.

 

 

WAIT A SECOND.

This would be pretty difficult to do, but... You see how they did the little "rung" things all the way up the length of the cylinder? Why would they do that unless something was going to be there?

What if... What if the whole fin moves forwards and backwards along the body of the Starship? This could be combined with the tips of the fins being bent backwards for stability, or with articulate tips or canards. This solves the problem of having a hinge that has to provide insane amounts of torque while still allowing for a large degree of control over where the center of pressure is in relation to the center of mass.

Of course, shielding it from re-entry would be a real pain...

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I am pretty sure the entire wings articulate. The gap looks like that. Also, the axis of rotation looks like it will be just past the chord edge, so that's another reason for the gap.

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3 minutes ago, Ultimate Steve said:

If only the ends articulate, then what would the big space between the body and the fin be there for? I think that a lot of people were theorizing that it was for the fin actuator.

 

 

WAIT A SECOND.

This would be pretty difficult to do, but... You see how they did the little "rung" things all the way up the length of the cylinder? Why would they do that unless something was going to be there?

What if... What if the whole fin moves forwards and backwards along the body of the Starship? This could be combined with the tips of the fins being bent backwards for stability, or with articulate tips or canards. This solves the problem of having a hinge that has to provide insane amounts of torque while still allowing for a large degree of control over where the center of pressure is in relation to the center of mass.

Of course, shielding it from re-entry would be a real pain...

That would be what those gap-cover-thingies would be for, then! I like this idea, it's completely crazy. We're talking SpaceX, so crazy is good!

 

So, 4 main options here:

  1. 2 fins, actuate in entirety, whole fins already mounted.
  2. 2 wings, tips articulate only.
  3. 2 wings, tips and body both articulate separately, so the hinge gap thing is still explained.
  4. This... madness. Awesome madness.

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There are images of fillet parts that cover the gap.

 

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Sooo, that monolith thing is the windbreaker. For some reason I thought it would be white.

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22 minutes ago, Wjolcz said:

Sooo, that monolith thing is the windbreaker. For some reason I thought it would be white.

As its polished steel it will be white if reflecting white. Hint try to sneak up on it as an white barn. 

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17 hours ago, RealKerbal3x said:

What do you mean? If the fins have legs attached, that would mean that they would have to bear the load of the craft sitting on the ground, so they would need to be more strengthened that how this looks:

I mean legs mounted to the fuselage, but some sort of structure would make the legs slanted and wider.

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I'm really curious as to where the legs will be. There's really not much room to fit them under the tanks. Especially since there will also be VacRaptors somewhere under there. Unless they are planning to have 2 instead of 3 of those, or something.

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1 hour ago, Wjolcz said:

I'm really curious as to where the legs will be. There's really not much room to fit them under the tanks. Especially since there will also be VacRaptors somewhere under there. Unless they are planning to have 2 instead of 3 of those, or something.

Probably extending-ram legs from the corners of the "aft cargo" area on either side of the vac bells.

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29 minutes ago, Flying dutchman said:

Second fin going on right now.

Are they still using the foldable fins? 

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