Starship heat shield

[Nomadd]

 I have no idea how they make it, but the white stuff is very light and crumbly in it's final form. The brackets are pretty tight and don't seem like they can move around. The channel is packed with white powder, but I can't tell if that's just a result of the insertion, or they pack it in manually.

 I'm trying to think of a vibrator where I could control axis, amplitude, waveform and frequency for experimentation.
 Or maybe just strap em on a speaker with AC/DC playing.

[Ben Baley]

It seems to me that the easiest way to insert the bracket would be to machine a channel slightly smaller than the bracket and then insert them. That way they would be wedged in there and as long as the size difference is properly controlled would allow for a tight fit without overstressing and cracking the tile

[edzieba]

- Press cleaned Silica fibres (cleaning occurs at Cidco Road) into mould to create tile preform
- Sinter tile preform in furnace
- Mill sintered preform to size and shape, split preform (double-sided, flat-face to flat-face, so front and backside can be milled to shape) into individual tile blanks
- Press mounting plates into tile blank - the tiles are very frangible, little force is needed and no pre-milling.
- Apply RCG coating
- Sinter RCG coating (singe-sided heating, tile backside not heated to avoid insert damage, helps that the tiles are such good insulators)
- Infiltrate with waterproofing agent (MTMS).

In composition, the tiles are nearly identical to the STS tiles (sintered Silica 'foam' with Borosilicate glass coating). STS tiles did not have the inserts, and were a different shape without the rear cavities. The Silicone-adhered tiles on Starship are even closer to STS, lacking the metal inserts and having conformal backsides rather than the hollowed-out backs of the pin attached tiles.

[Oersted]

So, the hollowed-out backsides are what permit the brackets to slide in?

[Oersted]

Paid the old homestead a visit today and cleaned up the mudflats some.

Would love to see the tile from a couple of other angles, Nomadd, I have a hard time understanding the geometry of it.

Nice find!

[RamsesBic]

Paid the old homestead a visit today and cleaned up the mudflats some.

Would love to see the tile from a couple of other angles, Nomadd, I have a hard time understanding the geometry of it.

Nice find!

Nomadd posted pictures already. See https://forum.nasaspaceflight.com/index.php?topic=50748.3260

[edzieba]

So, the hollowed-out backsides are what permit the brackets to slide in?

No, they just save mass. And save on Silica, which reduces cost (and the reduced overall thickness may also speed up sintering time, which will also save cost).

[Oersted]

Paid the old homestead a visit today and cleaned up the mudflats some.

Would love to see the tile from a couple of other angles, Nomadd, I have a hard time understanding the geometry of it.

Nice find!

Nomadd posted pictures already. See https://forum.nasaspaceflight.com/index.php?topic=50748.3260

I didn't find any more pics of that tile in your link.

[RamsesBic]

Paid the old homestead a visit today and cleaned up the mudflats some.

Would love to see the tile from a couple of other angles, Nomadd, I have a hard time understanding the geometry of it.

Nice find!

Nomadd posted pictures already. See https://forum.nasaspaceflight.com/index.php?topic=50748.3260

I didn't find any more pics of that tile in your link.

Not sure what images you hope to see beyond those. It is not like SpaceX allows photographers into their tile production factory.

[Oersted]

RamsesBic, I refer you to reply #3311 in this thread, where a fellow called Nomadd posted a pic of a broken tile he found near the SpaceX facilities in Boca Chica. I just asked him if he would mind posting a few more pics, from different angles, of that broken tile.

[whitelancer64]

Paid the old homestead a visit today and cleaned up the mudflats some.

Would love to see the tile from a couple of other angles, Nomadd, I have a hard time understanding the geometry of it.

Nice find!

Assuming you still have it in your possession, I would also be very interested in the weight of this tile fragment.

[OTV Booster]

Am I missing something? The tiles are sintered? This is the first I've heard of this.


Sintering is a pressure process. Even if the tile material were sintered I don't see how the glaze could be sintered on.


Can somebody unconfuse me?

[eriblo]

Am I missing something? The tiles are sintered? This is the first I've heard of this.


Sintering is a pressure process. Even if the tile material were sintered I don't see how the glaze could be sintered on.


Can somebody unconfuse me?

Sintering involves pressure and/or heat. Materials like these are sintered at high temperatures at atmospheric pressure just like pottery.

[OTV Booster]

Am I missing something? The tiles are sintered? This is the first I've heard of this.


Sintering is a pressure process. Even if the tile material were sintered I don't see how the glaze could be sintered on.


Can somebody unconfuse me?

Sintering involves pressure and/or heat. Materials like these are sintered at high temperatures at atmospheric pressure just like pottery.

Never heard the term used that way. For ceramics, the familiar term is baking or firing.


Broadly speaking, my familiarity with sintering involves pressure which generally results in heat but heat can be added. Individual particles fuse at the point of contact without general melting, creating a matrix with open spaces throughout.


Hmmm, that last does describe the tile material, so I'll just shut up and grok. Live and learn.


BTW, the glaze would not be an open matrix. In the pottery world, goop with glass in it is painted on and fired high enough that the glass softens and runs together into a solid layer. Porcelain can be thought of as all glaze with no substrate.

[edzieba]

Am I missing something? The tiles are sintered? This is the first I've heard of this.


Sintering is a pressure process. Even if the tile material were sintered I don't see how the glaze could be sintered on.


Can somebody unconfuse me?

Sintering involves pressure and/or heat. Materials like these are sintered at high temperatures at atmospheric pressure just like pottery.

Never heard the term used that way. For ceramics, the familiar term is baking or firing.


Broadly speaking, my familiarity with sintering involves pressure which generally results in heat but heat can be added. Individual particles fuse at the point of contact without general melting, creating a matrix with open spaces throughout.


Hmmm, that last does describe the tile material, so I'll just shut up and grok. Live and learn.


BTW, the glaze would not be an open matrix. In the pottery world, goop with glass in it is painted on and fired high enough that the glass softens and runs together into a solid layer. Porcelain can be thought of as all glaze with no substrate.

Sintering using mechanical pressure is unsuitable for the the tiles, as pre-crushing the porous tile renders it ineffective in terms of its desired insulating properties. There are also plenty of ceramics and metallics that are vacuum sintered - e.g. tungsten carbide tooling inserts - or sintered at atmospheric pressure (though not always in regular air).

[InterestedEngineer]

This video, at the 6:49 -> 7:15 mark, shows the mesh that holds down the blanket gets easily melted by the sparks / blast flying off from the welder that is taking apart a ring:



It reminds me of what plastic might look like after melting it.

It'll be interesting seeing a tile repair with melted material behind it getting replaced after a reentry.

Snapshot of video with the welder part way down its cut.

[RamsesBic]

Does the plastic mesh have any function other than keeping the thermal blankets from getting loose before the tiles are added?

[InterestedEngineer]

Does the plastic mesh have any function other than keeping the thermal blankets from getting loose before the tiles are added?

After watching the blowtorch melt the mesh, I'd say the answer is "no".

I thought the mesh might have a high enough operating temperature to keep flapping down in the event of a lost tile, but the video falsifies that hypothesis.

[edzieba]

The same gas-axe also chews right through the felt pads with impunity. Contrary to some oft-repeated claims, refractory wools are great at handling radiant heat, but not so great at dealing with direct impingement heating.

[JCopernicus]

Why don't they cover the mount in the heat shield material on the ship?

My first guess is that the thrusters are a lot hotter than the re entry temps?

And if so then I just answered my own question?