totm nov 2023 SpaceX Discussion Thread

[RealKerbal3x]

Speaking of heatshield: A tiled flap (!)

Edit: ninja'd by @tater again

Edited July 16, 2021 by RealKerbal3x

[tater]

What I want on top of the circles where the thruster posts are at the corners:

Spoiler

 

[HvP]

3 hours ago, JoeSchmuckatelli said:

That looks like it will add a lot of weight to one side of the craft. 

I presume the engines are powerful enough and can gimbal enough to compensate for it

The Starships have all been landing using engines that are firing from off-center placement because some get turned off on the way down. This means that they are gimbaling well enough to compensate for the weight of the entire craft being off-center. They can handle the difference of having tiles on one side.

[JoeSchmuckatelli]

1 hour ago, tater said:

What I want on top of the circles where the thruster posts are at the corners:

  Hide contents

 

Okay - except SpaceX.... so it will look like this:

 

[CatastrophicFailure]

16 minutes ago, JoeSchmuckatelli said:

Okay - except SpaceX.... so it will look like this

I was thinking more this...

[StrandedonEarth]

2 hours ago, tater said:

What I want on top of the circles where the thruster posts are at the corners:

 

Those two white circles near the stern make me think the stern needs to look more like...

Spoiler

 

[Silavite]

Looks like the engine config is confirmed (or perhaps I missed an earlier confirmation).

[tater]

 

[sevenperforce]

1 hour ago, Silavite said:

Looks like the engine config is confirmed (or perhaps I missed an earlier confirmation).

The fact that they are only installing three Raptors on BN3 for the static fire told me that they were almost definitely doing 3-10-20.

[sevenperforce]

This is incredible to see.

Curved tiles galore. Each of the tiles cut to size to fit. Some very special “ring cap” tiles at the top. 

The tile nearest the ring cap is cut to size. It’s hard to tell for sure but it looks like the other tiles are getting larger as you go down the root...but maybe that’s just perspective.

It seems that they are going Full Shuttle. Well, not quite full Shuttle; they still have pure hex tiles on most of the vehicle. But they clearly have no qualms about using aggressively custom tiles wherever they need them. 

[sevenperforce]

Another really cool look....

Look closely at the three tiles going from the top of the flap root forward. One of the tiles is clearly a transition tile from the thicker tiles at that flap root to the thinner “standard” tiles along the overall flap body. Also, those super-thick curved tiles DON’T have the cloth underlayment, but the “standard” tiles do.

It really looks like they used computer modeling to say “here is where we need special tiles, and here is how they are shaped, and here is how they fit into the ordinary tiles we use everywhere else.”

[tater]

5 hours ago, sevenperforce said:

It seems that they are going Full Shuttle. Well, not quite full Shuttle; they still have pure hex tiles on most of the vehicle. But they clearly have no qualms about using aggressively custom tiles wherever they need them. 

The Shuttle was 23,000+ unique tiles, right? They can be a few orders of magnitude fewer and still be a low tile count.

4 hours ago, sevenperforce said:

It really looks like they used computer modeling to say “here is where we need special tiles, and here is how they are shaped, and here is how they fit into the ordinary tiles we use everywhere else.”

Yeah, exactly. It was said a long ways up the thread (maybe by me, maybe someone else), but while SpaceX "builds stuff" and tests it out at McGreggor and Boca Chica, they also do a lot of modeling. test until you break stuff doesn't mean that things are not meticulously designed and modeled, it's just that they don't screw around, and test/iterate quickly.

This is fascinating to watch.

[RyanRising]

1 hour ago, tater said:

The Shuttle was 23,000+ unique tiles, right? They can be a few orders of magnitude fewer and still be a low tile count.

Yeah, exactly. It was said a long ways up the thread (maybe by me, maybe someone else), but while SpaceX "builds stuff" and tests it out at McGreggor and Boca Chica, they also do a lot of modeling. test until you break stuff doesn't mean that things are not meticulously designed and modeled, it's just that they don't screw around, and test/iterate quickly.

This is fascinating to watch.

I was going to say that was the total number of tiles on the shuttle, not necessarily the number of unique ones, but: 

“No two tiles are exactly alike.” - https://www.nasa.gov/sites/default/files/atoms/files/shuttle_tiles_9_12v2.pdf

NASA, what off Earth were you doing?

Edited July 17, 2021 by RyanRising

[sevenperforce]

6 hours ago, RyanRising said:

I was going to say that was the total number of tiles on the shuttle, not necessarily the number of unique ones, but: 

“No two tiles are exactly alike.” - https://www.nasa.gov/sites/default/files/atoms/files/shuttle_tiles_9_12v2.pdf

NASA, what off Earth were you doing?

That lesson plan also said the heat from re-entry comes from friction and claimed foam strikes happen on orbit, so take it with a grain of salt. Not everyone who works at NASA knows everything about the Shuttle.

[tater]

Over coffee just now I looked up Shuttle tiles. The sites say 24,300 "unique" tiles but I get the feeling they probably are not using "unique" in the technical way I mean it. Looking at the various images of Shuttle, and the maps of tiles, some look like they might be the same, at least on the bottom of the vehicle, and other non-curved parts of the fuselage. Still, of the 24,300 tiles, I have to imagine many are specific to a particular spot. Reading a thread about them NASA said about flown tiles offered to schools that they were $1000 each, new, and ~$10,000/ft² installed (based on tile sizes that suggests a multiple of tile cost in labor to install them).

Pretty sure SS won't have $24M worth of tiles on it (~$80M, installed at Shuttle prices assuming ~750m² of tiles).

Edited July 18, 2021 by tater

[cubinator]

I was hanging out underneath Endeavour yesterday and got a good look at the tiles. Yeah, there are a lot of similar-looking rectangular tiles, but it could be that they have slight curves or varying depths that we can't see. What was really scary was the quantity of scores and dents in the heat shield from launch debris. There is a ~6 ft long stretch of replaced tiles, insinuating a scar that long on a previous flight. That is what Starship will hopefully avoid, so the tiles won't take such an absurd beating on every launch. Shuttle tiles seem to have taken more damage during LAUNCH than in performing their actual function.

[sevenperforce]

3 minutes ago, cubinator said:

I was hanging out underneath Endeavour yesterday and got a good look at the tiles. Yeah, there are a lot of similar-looking rectangular tiles, but it could be that they have slight curves or varying depths that we can't see. What was really scary was the quantity of scores and dents in the heat shield from launch debris. There is a ~6 ft long stretch of replaced tiles, insinuating a scar that long on a previous flight. That is what Starship will hopefully avoid, so the tiles won't take such an absurd beating on every launch. Shuttle tiles seem to have taken more damage during LAUNCH than in performing their actual function.

Yep, absolutely. They never failed at the job they were supposed to do.

As much as I love the idea of a 1.5-stage-to-orbit vehicle, it’s just a fundamentally bad idea outside of KSP.

[wumpus]

30 minutes ago, sevenperforce said:

Yep, absolutely. They never failed at the job they were supposed to do.

As much as I love the idea of a 1.5-stage-to-orbit vehicle, it’s just a fundamentally bad idea outside of KSP.

Note that this largely applies to resusable vehicles.  Most early rockets (including Sputnik) were 1.5.  2.5 makes a lot more sense, but still requires an additional engine, controls, etc and lighting the engine in vacuum.

[Elthy]

2 hours ago, tater said:

Reading a thread about them NASA said about flown tiles offered to schools that they were $1000 each

Bringing that cost down is propably a big priority for SpaceX and i doubt they will have much difficulty getting it way below 100$. They made way more complicated parts cheaper than anyone ever thought possible...

[tater]

That $1000 each I'm sure was what NASA paid retail on average. With each as a special, unique flower, mass production is sorta hard, for all we know they were also Shuttle specific (Columbia, Challenger, Endeavour, etc).

 

[RyanRising]

5 hours ago, sevenperforce said:

That lesson plan also said the heat from re-entry comes from friction and claimed foam strikes happen on orbit, so take it with a grain of salt. Not everyone who works at NASA knows everything about the Shuttle.

Ah, thanks. I was kind of hoping that was wrong, but didn't look into it close enough to see that it could be.

[JcoolTheShipbuilder]

How many raptors have been hatched built so far?

[mikegarrison]

11 hours ago, RyanRising said:

Ah, thanks. I was kind of hoping that was wrong, but didn't look into it close enough to see that it could be.

I believe every tile was individually numbered. That was not necessarily because they were all custom-shaped.

[cubinator]

7 hours ago, mikegarrison said:

I believe every tile was individually numbered. That was not necessarily because they were all custom-shaped.

Yes, every one has a serial number on it, this would be so the inspecting person could say "Tile xxxx-xxxxxx needs replacing" and they would know what type of tile it is and where to find it on the ship.

[RCgothic]

Tower gets its final level.