Wiki Super Heavy/Starship - General Development Discussion

[JB47394]

From today's LabPadre video.

A blurry picture of a "booster cap". I can't figure out what this is for other than perhaps simply as a dust and rain cover to protect electronics, motors and such. It seems to seat directly on top of the booster, with no room for anything to go on top of it.

 

[ecarfan]

Yes, that’s kind of odd. But if water and dust protection is the purpose, why use steel? A properly designed and secured tarp would do for less cost and easy removability.

If this “cap” is permanent then the interstage dome will have to fit over it. And the “cap” adds quite a bit of weight. So that doesn’t seem to make any sense. Of course SpaceX knows what they are doing and whatever it is, it has a reason for being.

 

[JB47394]

A properly designed and secured tarp would do for less cost and easy removability.

Primarily because they do steel. They can design it for their needs, fabricate it with material and equipment on hand, lift it with machinery on hand, repair it with current training, and even scrap it along with the rest of their stainless steel junk. A tarp would need lots of steel reinforcement anyway because it needs to secure to the booster all around the perimeter (nearly 30 meters) and it also needs support in the center so water accumulation doesn't turn into a pool liner. It's just not worth the effort.

The fact that it's white suggests that something more is going on than just water and dust protection. I believe that painting it white would keep things cooler underneath, so it doesn't turn the top of the booster into a sauna. There's also the possibility that the white is the underlayment for thermal tiles, which would suggest something much more radical than just a cover.

It's the only picture that I can find of it, whatever it is. I guess we wait and see.

 

[JB47394]

An image from the "What About It?" YouTube channel showing how metal is embedded in a tile so that it can be firmly mounted to the pins on the Starship skin.

 

[scaesare]

Cool pic.

So, I'm sure they have already thought of this, but I wonder if bending the edges of the side of the slot downwards a bit, to create a more pronounced "edge", and have a negative angle undercut on the bottom of the head on the pins, to create a "barb" for it to catch on, would help with retention. If they had enough insulation material underneath that when compressed would provide some back-tension.it seems like it might hold better...

I'd like to see a similar closeup of the pins...

 

[JB47394]

I'd like to see a similar closeup of the pins...

This is the best I could find. I can't quite make out the purpose of the pin ends. Clearly they pinch to go through the square holes in the tile, then spread out again, but there seems to be some very specific shape to the pin ends. It also looks like the pins are each oriented to the center of the tile. My guess is that it helps deal with vibration (any given vibration would could have a strong negative effect on only one pin at a time).

 

[ecarfan]

Interesting shape at the ends. And the pins are not all oriented the same way.

 

[Max Spaghetti]

They must have poached an engineer from Tesla to get panel gaps like that!

 

[Buckminster]

https://twitter.com/x/status/1776776455634190703

 

[mongo]

This is the best I could find. I can't quite make out the purpose of the pin ends. Clearly they pinch to go through the square holes in the tile, then spread out again, but there seems to be some very specific shape to the pin ends. It also looks like the pins are each oriented to the center of the tile. My guess is that it helps deal with vibration (any given vibration would could have a strong negative effect on only one pin at a time).

The slots are rectangular, so the pins align radially.

An image from the "What About It?" YouTube channel showing how metal is embedded in a tile so that it can be firmly mounted to the pins on the Starship skin.

View attachment 1035932

 

[Buckminster]

Does Raptor 3 get introduced on Starship 2 or 3?

 

[ecarfan]

So it appears that Starship V2 has a different hot staging ring that is taller (includes the “booster cap” that @JB47394 posted about upthread?) but the grid fins are lower and the part of the vehicle below the staging ring is also taller. And the protective skirts around the engines is gone. Unnecessary mass?

 

[JB47394]

The slots are rectangular, so the pins align radially.

Or tangentially, but I think the closeup suggests radially.

 

[winfield100]

https://twitter.com/x/status/1776776455634190703

View attachment 1036339
View attachment 1036340

OT
an ?off topic? observation

Starship 3 is 150m tall
the Washington monument is Washington DC, USA is 169m tall

It's almost like flinging the monument into space, or at least LEO, a heck of a long way from "Grasshopper" not that long ago

 

[JB47394]

Does Raptor 3 get introduced on Starship 2 or 3?

We'll have to wait and see, but as @ecarfan observes, the pictures of the V2 and V3 boosters have naked engines - no cladding at all. That would suggest to me that they are Raptor 3s.

So it appears that Starship V2 has a different hot staging ring that is taller (includes the “booster cap” that @JB47394 posted about upthread?) but the grid fins are lower and the part of the vehicle below the staging ring is also taller. And the protective skirts around the engines is gone. Unnecessary mass?

I didn't even look at the images until your post.

It certainly does look like a booster cap in there, that it's in there to protect the top of the booster. I'm tickled to see that they depicted that Soviet-style hot staging standoff, with the open, diagonal bracing that I was hoping for.

The grid fins look like they might be the same as on the current booster, but moved to a 90 degree spacing. Elon had said at one time that having four grid fins of that size was overkill, but they seem to be planning on keeping them. The lower placement could have to do with hot staging, and certainly it will impact the vehicle aerodynamics. I think it produces less stability, meaning more maneuverability. With computer control, the reduced stability shouldn't present any issues.

The exposed engines are probably Raptor 3s, with builtin cooling and other durability features. Certainly it results in the elimination of a lot of mass. I guess they're confident enough about engine reliability to not worry about armoring them against RUDs. Certainly having fewer exposed parts on the engine will help with surviving RUDs of adjacent engines.

The last thing I noticed is the buttons at the base of the boosters. There would be four of them. The only thing that comes to mind is that they could be thrusters, but if they have gimbaling engines, why bother? Or will they eliminate gimbaled engines (weight and complexity) and go with lateral thrusters? Or is that just robbing Peter to pay Paul?

Starship 3 is 150m tall

Yeah, that really jumped out at me as well. I imagine it lying down on an American football field, which is 110 meters from the end of one end zone to the end of the other. It would still stick out 20 meters beyond on each end.

 

[scaesare]

This is the best I could find. I can't quite make out the purpose of the pin ends. Clearly they pinch to go through the square holes in the tile, then spread out again, but there seems to be some very specific shape to the pin ends. It also looks like the pins are each oriented to the center of the tile. My guess is that it helps deal with vibration (any given vibration would could have a strong negative effect on only one pin at a time).

Hehe.... did you steal that from my post a few pages back, or did you steal it from the same place I stole it?

Yeah we had some subsequent discussion and it's hard to make out the actual head design.. if they are rounded all the way or there's and edge/barb on the bottom. Even if it is the latter, I wonder if having the tile slot edges bent inward a bit to present more of an edge to capture the pin barbs would help...

 

[scaesare]

https://twitter.com/x/status/1776776455634190703

View attachment 1036339
View attachment 1036340

So he seems to be theorizing that Starship v3 would require a Raptor v4 at 303 tons of thrust:

https://twitter.com/x/status/1776743201828720741

 

[JB47394]

Hehe.... did you steal that from my post a few pages back, or did you steal it from the same place I stole it?

I only steal from the web. I don't even remember you making that post. I guess I needed the tile side to make it all come together in my mind.

Yeah we had some subsequent discussion and it's hard to make out the actual head design.. if they are rounded all the way or there's and edge/barb on the bottom. Even if it is the latter, I wonder if having the tile slot edges bent inward a bit to present more of an edge to capture the pin barbs would help...

I'd like to see something like metallic Velcro, where no single contact is all that strong, but the cumulative effect is very strong. Certainly it would provide a lot of redundancy and distribute the load into the tile. It would work better for the places where there is no fabric backing. I wonder if the fabric could be reengineered to be the fabric side of the velcro.

So he seems to be theorizing that Starship v3 would require a Raptor v4 at 303 tons of thrust:

From my other post:

Elon: "I think ultimately we'll probably aim to get the booster engines over 330 tons of thrust, which would mean 10,000 tons of total thrust at liftoff."

It would actually mean 10,890 if they stick with 33 engines.

 

[scaesare]

I only steal from the web. I don't even remember you making that post. I guess I needed the tile side to make it all come together in my mind.

I was joking ya know... hence my reference to my also having stolen it...

I'd like to see something like metallic Velcro, where no single contact is all that strong, but the cumulative effect is very strong. Certainly it would provide a lot of redundancy and distribute the load into the tile. It would work better for the places where there is no fabric backing. I wonder if the fabric could be reengineered to be the fabric side of the velcro.

That would be interesting.... and fun to listen to as tiles re removed.

From my other post:

Elon: "I think ultimately we'll probably aim to get the booster engines over 330 tons of thrust, which would mean 10,000 tons of total thrust at liftoff."

It would actually mean 10,890 if they stick with 33 engines.

Ah cool.. my turn to not have recalled seeing one of your posts... I'll check it out... thanks.

 

[ecarfan]

It certainly does look like a booster cap in there, that it's in there to protect the top of the booster. I'm tickled to see that they depicted that Soviet-style hot staging standoff, with the open, diagonal bracing that I was hoping for.

And they just look cooler than the first iteration.

The last thing I noticed is the buttons at the base of the boosters. There would be four of them. The only thing that comes to mind is that they could be thrusters, but if they have gimbaling engines, why bother? Or will they eliminate gimbaled engines (weight and complexity) and go with lateral thrusters?

They look like thrusters to me. Maybe they will reduce the number of gimbaled engines? But adding thrusters adds complexity and cost. My totally non-expert feeling is that certainly some gimbaled thrusters are needed.