Off topic, but not entirely. The cost ratio of titanium:stainless steel is around 15:1, and welding 9 meter titanium rings together would have to be done robotically in a gigantic tank filled with inert gas. So there are huge economic reasons for going with steel, even for the Starship upper stage.However, titanium has been used in megaprojects, the Russian nuclear submarine K-336 Pskov has a dry mass of 7,600 tonnes, most of that being the titanium hull. The Starship upper stage has a dry mass of ~100 tonnes, of which almost 10 tonnes would be 6 Raptor engines. Still, replacing the tanks, pipes, and skin with titanium could shave 40 tonnes off the mass, giving a 60 tonne Starship with 40 tonnes more payload to LEO. The cost of 50 tonnes of titanium would be about $5 million, cheap compared to $17 Billion for rights to frequencies . The fabrication costs are the rub.Anyway, titanium having a higher melting point than steel has to have some positives for tolerating repeated reentries. Has titanium ever been seriously discussed as a structural material for the Starship upper stage?
Quote from: meekGee on 09/11/2025 02:09 amQuote from: catdlr on 09/10/2025 11:32 pmI no longer consider it a blanket, but rather a part of the tile backing, mounted by the tile robot in alternating placement. This way, the tiles have a gap filler made of the same material between them, eliminating the need for laborious hand placement.In the third picture, the areas in green are what you see in the above two images (Tiles with the white gap fillers). The area in red was not present with those, and there were areas on the nose cone where no tiles were present; additionally, the white backing was painted black (which resulted in the white coating of the nose cone and several areas along the spine). The Area in orange is a special tile test area and also survived.Quote from: catdlr on 09/09/2025 09:44 pmQuote from: catdlr on 09/09/2025 09:31 pmQuote from: DanClemmensen on 09/09/2025 09:23 pmQuote from: catdlr on 09/09/2025 08:49 pmFor those wanting to find out what's in store for V3, read this article.QuoteArs Technica@arstechnicaSpaceX’s lesson from last Starship flight? “We need to seal the tiles.”ARTICLE: SpaceX’s lesson from last Starship flight? “We need to seal the tiles.”For those who did not read the article, the headline is slightly misleading. It's not about sealing individual tiles against moisture. It's about filling the gaps between tiles to keep the reentry plasma from reaching the ablative backup layer. In particular, they used their neat new "crush wrap" approach for most of the tiles, and it worked. "Crush wrap" is that fabric-looking stuff that is installed under each tile indivitually with its edges sticking out of the gap all the way around. After pushing the tile down on its pins, the stuff that sticks out is trimmed flush. Apparently, this is quick to install and can fly multiple times without per-flight maintenance.I've seen this being installed on the ship. Let me find an image, probably from a Starship Gazer.Presented here in this image are two samples of the specified tile type featuring the "crunch wrap." The pre-cut white fabric backing will fold between the tiles, creating a two-layer fabric structure between each tile. Alternatively, they can be arranged to alternate; in one configuration, the fabric will lie flat, and in the other, it will be installed between two tiles, causing the fabric to fold upwards and serve as a gap filler between each tile.The second photo illustrates two tiles butting up to each other in the RED-highlighted boxPhoto Credit: Starship GazerSure but as shown, the blanket would interfere with the adjacent unit being placed.Easily solvable with a bit of packaging of course, just need to be wary of friction during the install pushing one of the blanket leafs under the tile.Easier than that. First pass is every other Pin set, second pass filling in the gaps between them, and when pressing the tile, the blanket automatically fills in the gap. The tiles on the first pass lay flat, providing ship skin protection between tiles in case of blow-through. Td-da. The proof is in the picture, and note the wings being installed in the factory Starship Nursery row.
Quote from: catdlr on 09/10/2025 11:32 pmI no longer consider it a blanket, but rather a part of the tile backing, mounted by the tile robot in alternating placement. This way, the tiles have a gap filler made of the same material between them, eliminating the need for laborious hand placement.In the third picture, the areas in green are what you see in the above two images (Tiles with the white gap fillers). The area in red was not present with those, and there were areas on the nose cone where no tiles were present; additionally, the white backing was painted black (which resulted in the white coating of the nose cone and several areas along the spine). The Area in orange is a special tile test area and also survived.Quote from: catdlr on 09/09/2025 09:44 pmQuote from: catdlr on 09/09/2025 09:31 pmQuote from: DanClemmensen on 09/09/2025 09:23 pmQuote from: catdlr on 09/09/2025 08:49 pmFor those wanting to find out what's in store for V3, read this article.QuoteArs Technica@arstechnicaSpaceX’s lesson from last Starship flight? “We need to seal the tiles.”ARTICLE: SpaceX’s lesson from last Starship flight? “We need to seal the tiles.”For those who did not read the article, the headline is slightly misleading. It's not about sealing individual tiles against moisture. It's about filling the gaps between tiles to keep the reentry plasma from reaching the ablative backup layer. In particular, they used their neat new "crush wrap" approach for most of the tiles, and it worked. "Crush wrap" is that fabric-looking stuff that is installed under each tile indivitually with its edges sticking out of the gap all the way around. After pushing the tile down on its pins, the stuff that sticks out is trimmed flush. Apparently, this is quick to install and can fly multiple times without per-flight maintenance.I've seen this being installed on the ship. Let me find an image, probably from a Starship Gazer.Presented here in this image are two samples of the specified tile type featuring the "crunch wrap." The pre-cut white fabric backing will fold between the tiles, creating a two-layer fabric structure between each tile. Alternatively, they can be arranged to alternate; in one configuration, the fabric will lie flat, and in the other, it will be installed between two tiles, causing the fabric to fold upwards and serve as a gap filler between each tile.The second photo illustrates two tiles butting up to each other in the RED-highlighted boxPhoto Credit: Starship GazerSure but as shown, the blanket would interfere with the adjacent unit being placed.Easily solvable with a bit of packaging of course, just need to be wary of friction during the install pushing one of the blanket leafs under the tile.
I no longer consider it a blanket, but rather a part of the tile backing, mounted by the tile robot in alternating placement. This way, the tiles have a gap filler made of the same material between them, eliminating the need for laborious hand placement.In the third picture, the areas in green are what you see in the above two images (Tiles with the white gap fillers). The area in red was not present with those, and there were areas on the nose cone where no tiles were present; additionally, the white backing was painted black (which resulted in the white coating of the nose cone and several areas along the spine). The Area in orange is a special tile test area and also survived.Quote from: catdlr on 09/09/2025 09:44 pmQuote from: catdlr on 09/09/2025 09:31 pmQuote from: DanClemmensen on 09/09/2025 09:23 pmQuote from: catdlr on 09/09/2025 08:49 pmFor those wanting to find out what's in store for V3, read this article.QuoteArs Technica@arstechnicaSpaceX’s lesson from last Starship flight? “We need to seal the tiles.”ARTICLE: SpaceX’s lesson from last Starship flight? “We need to seal the tiles.”For those who did not read the article, the headline is slightly misleading. It's not about sealing individual tiles against moisture. It's about filling the gaps between tiles to keep the reentry plasma from reaching the ablative backup layer. In particular, they used their neat new "crush wrap" approach for most of the tiles, and it worked. "Crush wrap" is that fabric-looking stuff that is installed under each tile indivitually with its edges sticking out of the gap all the way around. After pushing the tile down on its pins, the stuff that sticks out is trimmed flush. Apparently, this is quick to install and can fly multiple times without per-flight maintenance.I've seen this being installed on the ship. Let me find an image, probably from a Starship Gazer.Presented here in this image are two samples of the specified tile type featuring the "crunch wrap." The pre-cut white fabric backing will fold between the tiles, creating a two-layer fabric structure between each tile. Alternatively, they can be arranged to alternate; in one configuration, the fabric will lie flat, and in the other, it will be installed between two tiles, causing the fabric to fold upwards and serve as a gap filler between each tile.The second photo illustrates two tiles butting up to each other in the RED-highlighted boxPhoto Credit: Starship Gazer
Quote from: catdlr on 09/09/2025 09:31 pmQuote from: DanClemmensen on 09/09/2025 09:23 pmQuote from: catdlr on 09/09/2025 08:49 pmFor those wanting to find out what's in store for V3, read this article.QuoteArs Technica@arstechnicaSpaceX’s lesson from last Starship flight? “We need to seal the tiles.”ARTICLE: SpaceX’s lesson from last Starship flight? “We need to seal the tiles.”For those who did not read the article, the headline is slightly misleading. It's not about sealing individual tiles against moisture. It's about filling the gaps between tiles to keep the reentry plasma from reaching the ablative backup layer. In particular, they used their neat new "crush wrap" approach for most of the tiles, and it worked. "Crush wrap" is that fabric-looking stuff that is installed under each tile indivitually with its edges sticking out of the gap all the way around. After pushing the tile down on its pins, the stuff that sticks out is trimmed flush. Apparently, this is quick to install and can fly multiple times without per-flight maintenance.I've seen this being installed on the ship. Let me find an image, probably from a Starship Gazer.Presented here in this image are two samples of the specified tile type featuring the "crunch wrap." The pre-cut white fabric backing will fold between the tiles, creating a two-layer fabric structure between each tile. Alternatively, they can be arranged to alternate; in one configuration, the fabric will lie flat, and in the other, it will be installed between two tiles, causing the fabric to fold upwards and serve as a gap filler between each tile.The second photo illustrates two tiles butting up to each other in the RED-highlighted boxPhoto Credit: Starship Gazer
Quote from: DanClemmensen on 09/09/2025 09:23 pmQuote from: catdlr on 09/09/2025 08:49 pmFor those wanting to find out what's in store for V3, read this article.QuoteArs Technica@arstechnicaSpaceX’s lesson from last Starship flight? “We need to seal the tiles.”ARTICLE: SpaceX’s lesson from last Starship flight? “We need to seal the tiles.”For those who did not read the article, the headline is slightly misleading. It's not about sealing individual tiles against moisture. It's about filling the gaps between tiles to keep the reentry plasma from reaching the ablative backup layer. In particular, they used their neat new "crush wrap" approach for most of the tiles, and it worked. "Crush wrap" is that fabric-looking stuff that is installed under each tile indivitually with its edges sticking out of the gap all the way around. After pushing the tile down on its pins, the stuff that sticks out is trimmed flush. Apparently, this is quick to install and can fly multiple times without per-flight maintenance.I've seen this being installed on the ship. Let me find an image, probably from a Starship Gazer.
Quote from: catdlr on 09/09/2025 08:49 pmFor those wanting to find out what's in store for V3, read this article.QuoteArs Technica@arstechnicaSpaceX’s lesson from last Starship flight? “We need to seal the tiles.”ARTICLE: SpaceX’s lesson from last Starship flight? “We need to seal the tiles.”For those who did not read the article, the headline is slightly misleading. It's not about sealing individual tiles against moisture. It's about filling the gaps between tiles to keep the reentry plasma from reaching the ablative backup layer. In particular, they used their neat new "crush wrap" approach for most of the tiles, and it worked. "Crush wrap" is that fabric-looking stuff that is installed under each tile indivitually with its edges sticking out of the gap all the way around. After pushing the tile down on its pins, the stuff that sticks out is trimmed flush. Apparently, this is quick to install and can fly multiple times without per-flight maintenance.
For those wanting to find out what's in store for V3, read this article.QuoteArs Technica@arstechnicaSpaceX’s lesson from last Starship flight? “We need to seal the tiles.”ARTICLE: SpaceX’s lesson from last Starship flight? “We need to seal the tiles.”
Ars Technica@arstechnicaSpaceX’s lesson from last Starship flight? “We need to seal the tiles.”
I'd like to address a different aspect of the heatshield.-snip-As an alternative, place a small ring around the pin before tile installation. The ring would be iron or a magnetic alloy that will not heat degrade. The diameter of the bottom of the pin, where the ring resides would be a tad less than the rest of the pin. To remove the tile place an electromagnet on the tile and draw the ring up out of its retaining groove. This will compress the pin and allow the retaining 'Y' to clear the barbs. The tile would then be free for removal.This would be a 'no banging' technique that would work in space in an emergency. The ring material is a big question. Thoughts?
I'd like to address a different aspect of the heatshield.Rapid reusability implies rapid tile repairs. AIUI, the current method of removing a tile is to break it with a hammer and expose the barbed split pins and retaining 'Y' structure embedded in the tile. Then the pins are compressed and the remaining debris is removed. This is slow and messy.As an alternative, place a small ring around the pin before tile installation. The ring would be iron or a magnetic alloy that will not heat degrade. The diameter of the bottom of the pin, where the ring resides would be a tad less than the rest of the pin. To remove the tile place an electromagnet on the tile and draw the ring up out of its retaining groove. This will compress the pin and allow the retaining 'Y' to clear the barbs. The tile would then be free for removal.This would be a 'no banging' technique that would work in space in an emergency. The ring material is a big question. Thoughts?
Quote from: OTV Booster on 09/11/2025 05:58 pmI'd like to address a different aspect of the heatshield.Rapid reusability implies rapid tile repairs. AIUI, the current method of removing a tile is to break it with a hammer and expose the barbed split pins and retaining 'Y' structure embedded in the tile. Then the pins are compressed and the remaining debris is removed. This is slow and messy.As an alternative, place a small ring around the pin before tile installation. The ring would be iron or a magnetic alloy that will not heat degrade. The diameter of the bottom of the pin, where the ring resides would be a tad less than the rest of the pin. To remove the tile place an electromagnet on the tile and draw the ring up out of its retaining groove. This will compress the pin and allow the retaining 'Y' to clear the barbs. The tile would then be free for removal.This would be a 'no banging' technique that would work in space in an emergency. The ring material is a big question. Thoughts?https://en.wikipedia.org/wiki/Curie_temperatureThe materials lose their magnetism, but necessarily their ability to become magnetic again.Heat them high enough, you lose the ability to be magnetic because of phase changes, change in crystal structure, etc.They'll also tend to oxidize, which will ruin magnetivity.Not sure the mass is worth it. If more than a dozen tiles are failing between missions, then that needs to be fixed. the current process of replacing tiles by destroying them probably scales to over 100-200, and there's no added mass which is a big problem for adding say 100g each to 10,000 tiles (= 1 ton)
My phrasing was clumsy. The ring wouldn't be magnetic. It would need to respond to a magnet.The pic shows the pin and ring in cross section. The proportions are wonky but I think it gets the idea across. I'm wagging 10g each or less. I suspect the pin diameter is set by handling needs and the strength is more than adequate, so thinning them at the base won't hurt and saves a bit of mass to counter part of the ring mass. Installing the tile seats the ring back on the bottom.
ChromeKiwi@AshleyKillip·Sep 9Amazing reading from Ars Technica with some great information about the latest tile test results from Starship flight 10. Metal tiles did not prove to be a good option hence the heavy oxidation seen after re entry with most of the ship turning external tank orange. The nose section of the ship had a large white patch this was caused by heat seeping between the tile gaps and eroding the underlying material. Flight 11 should be a little different and we could see a complete thermal protection system. One area was seen not suffering much damage this area was made up of 3 layers an Ablative base a material likely Pyron next a layer of Kaowool (ceramic fibre insulation) on top of this is a new material called crunch wrap and will be used under the tile with extra material on each of the tiles side faces folded around and cut flush once installed.
Steve Goyette@steveg3215This is a picture from @StarshipGazer on Ship 39. Do you think this is what you’re representing in your render?
ChromeKiwi@AshleyKillipYup you can see the Black ablative layer that rubber looking stuff with the holes the white Kaowool. then the wrap with the tile compressing it all and locking in with a new pin system.8:29 PM · Sep 11, 2025
Quote from: OTV Booster on 09/12/2025 02:53 amMy phrasing was clumsy. The ring wouldn't be magnetic. It would need to respond to a magnet.The pic shows the pin and ring in cross section. The proportions are wonky but I think it gets the idea across. I'm wagging 10g each or less. I suspect the pin diameter is set by handling needs and the strength is more than adequate, so thinning them at the base won't hurt and saves a bit of mass to counter part of the ring mass. Installing the tile seats the ring back on the bottom. Adds unnecesary massEither ring would have to be massive or magnet tool extremely strong (so awkward to work with, defeats the purpose)There will definitely be no thinning of the pins, I don't know if you aware but rockets shakes a bit when engines are running remember how many tiles where popping out on old vehicles?Tiles that need to be replaced will be mostly damaged anyway, won't they?
Upon closer inspection the new pins are more like flat tabs than wires. The ring might become more rectangular.I suspect that with one rubbery layer and two crushable fiber layers the tile will be preloaded against the barbs with the crush crunch wrap layer damping out vibration. edit: changed a word.
Been thinking about the crunch wrap and wondering what material(s) it could be made of or woven with that would help it contract under cryo temps and expand during re-entry heating.Could be a really valuable enabling solution.
Has anyone done the math to determine how much all of these additional heat shield components add weight to Starship? I'm wondering if this is part of the payload to orbit apparent payload shortfall that Starship seems to have currently? As I recall we were considering a mass of around 9 tonne for the heat shield a few years ago back in the version 1 ship days.
Quote from: northstar on 09/13/2025 08:20 pmHas anyone done the math to determine how much all of these additional heat shield components add weight to Starship? I'm wondering if this is part of the payload to orbit apparent payload shortfall that Starship seems to have currently? As I recall we were considering a mass of around 9 tonne for the heat shield a few years ago back in the version 1 ship days.I have suspected for sometime that the payload shortfall comprised of mostly 2 problems. Raptor thrust levels and heat shield weight. Hence the emphasis on both of those. Haven’t heard much at all of reducing mass elsewhere.
