Bulkheads*********Surface area: 211.2m²Volume: 0.419m³Weight: 3313kg...Weight (Empty shell)********************3 Bulkheads: 9939kg19 full rings: 30799kg1.42m tall bottom ring (77.64%): 1258.5kgLOX Header tank: 632.6kgFairing: 8974kg************************************************Total weight: 51.6t (Shell and tanks - empty)************************************************

Quote from: fael097 on 02/04/2020 12:47 amBulkheads*********Surface area: 211.2m²Volume: 0.419m³Weight: 3313kg...Weight (Empty shell)********************3 Bulkheads: 9939kg19 full rings: 30799kg1.42m tall bottom ring (77.64%): 1258.5kgLOX Header tank: 632.6kgFairing: 8974kg************************************************Total weight: 51.6t (Shell and tanks - empty)************************************************I think you tripled the bulkheads twice. They should be closer to 70 square meters, not 211 square meters each,so we are down by 6.6 tons to 45 tons.

Quote from: Smrg on 02/04/2020 02:18 amQuote from: fael097 on 02/04/2020 12:47 amBulkheads*********Surface area: 211.2m²Volume: 0.419m³Weight: 3313kg...Weight (Empty shell)********************3 Bulkheads: 9939kg19 full rings: 30799kg1.42m tall bottom ring (77.64%): 1258.5kgLOX Header tank: 632.6kgFairing: 8974kg************************************************Total weight: 51.6t (Shell and tanks - empty)************************************************I think you tripled the bulkheads twice. They should be closer to 70 square meters, not 211 square meters each,so we are down by 6.6 tons to 45 tons.Cross section of the cylinder of 9 m diameter is 63.6 m2. If the bulkhead were a half sphere, its surface would be twice the cross section, i.e. 127.2 m2. The real surface area of the bulkhead should be in between these two values.

There are also 3mm and 2mm coils laying around.

Interesting exercise.Is there a estimate for the heat shield? Surface area covered, multiple by thickness and density. The bottom thrust structure and legs would seem to be a hard estimate, but that's going to have a lot of weight in it.Looks like 100T could be possible.

Quote from: wannamoonbase on 02/04/2020 12:16 pmInteresting exercise.Is there a estimate for the heat shield? Surface area covered, multiple by thickness and density. The bottom thrust structure and legs would seem to be a hard estimate, but that's going to have a lot of weight in it.Looks like 100T could be possible.I could definitely estimate the surface area it will cover, and maybe thickness based on pictures, but I have no clue what the material density is

Quote from: fael097 on 02/04/2020 11:35 amQuote from: Nomadd on 02/04/2020 01:33 am There are also 3mm and 2mm coils laying around.I remember seeing pics of those coils, but have we seen any evidence of those being used, and for what parts? Also do we know the thickness of those curved nose cone parts that were shipped to the site? Somebody thought that thickness might be mostly based on pressure and not vertical loads, so the 4mm could go all the way to the top of the tank section. Or, 3mm might be more than enough to hold pressure. Or a dozen other things. I'm not really sure how much more accurate my guesses would be than a monkey with a dartboard. Probably a little less.

Quote from: Nomadd on 02/04/2020 01:33 am There are also 3mm and 2mm coils laying around.I remember seeing pics of those coils, but have we seen any evidence of those being used, and for what parts? Also do we know the thickness of those curved nose cone parts that were shipped to the site?

Quote from: fael097 on 02/04/2020 02:05 pmQuote from: wannamoonbase on 02/04/2020 12:16 pmInteresting exercise.Is there a estimate for the heat shield? Surface area covered, multiple by thickness and density. The bottom thrust structure and legs would seem to be a hard estimate, but that's going to have a lot of weight in it.Looks like 100T could be possible.I could definitely estimate the surface area it will cover, and maybe thickness based on pictures, but I have no clue what the material density isBest evidence is that the tiles are alumina / silica. The only dencity I have for the scintered material is 2.55 g/cc.Awesome new thread Rafael.

- TPS weight trends. I would guess 10-13 kg/m^2 on average for windward side including fins. - What do you calculate for the fuselage and fin areas?John

Quote from: livingjw on 02/05/2020 02:43 pm- TPS weight trends. I would guess 10-13 kg/m^2 on average for windward side including fins. - What do you calculate for the fuselage and fin areas?JohnJohn,Thanks that's a lot lower than I expected. Doing rough math on covering half of a 9 meter diameter vehicle 118 meters long with 13 kg/m^2 tile = 21,700 kg.

A bit more digging on the ceramics. Bulk density is around 2.5-3 g/cc but this doesn’t take account of voidage. At the extreme these materials can be blown to 95% voidage. Looking at commercial products Zircar Ceramics do a wide range with good strength, sustained max temperatures up to 1450 C and density down in the 0.3 - 0.5 g/cc range. This is probably an appropriate approximation.Did anybody estimate how thick the test tiles were?

Quote from: livingjw on 02/05/2020 02:43 pm- TPS weight trends. I would guess 10-13 kg/m^2 on average for windward side including fins. - What do you calculate for the fuselage and fin areas?JohnHalf fuselage has a surface area of 655m². I'm not considering raceway covers, shouldn't matter that much.Surface area of one side of a bottom fin is 42.11m² and top fin is 17.75m².So total heat shield area should be around 774.72m²Quote from: ThatOldJanxSpirit on 02/05/2020 01:52 pmA bit more digging on the ceramics. Bulk density is around 2.5-3 g/cc but this doesn’t take account of voidage. At the extreme these materials can be blown to 95% voidage. Looking at commercial products Zircar Ceramics do a wide range with good strength, sustained max temperatures up to 1450 C and density down in the 0.3 - 0.5 g/cc range. This is probably an appropriate approximation.Did anybody estimate how thick the test tiles were?Heat shield tiles seem to be 35cm in diameter and 3cm thick, so volume of a tile should be 2387cm³ or 0.002387m³

Quote from: fael097 on 02/05/2020 03:41 pmQuote from: livingjw on 02/05/2020 02:43 pm- TPS weight trends. I would guess 10-13 kg/m^2 on average for windward side including fins. - What do you calculate for the fuselage and fin areas?JohnHalf fuselage has a surface area of 655m². I'm not considering raceway covers, shouldn't matter that much.Surface area of one side of a bottom fin is 42.11m² and top fin is 17.75m².So total heat shield area should be around 774.72m²Quote from: ThatOldJanxSpirit on 02/05/2020 01:52 pmA bit more digging on the ceramics. Bulk density is around 2.5-3 g/cc but this doesn’t take account of voidage. At the extreme these materials can be blown to 95% voidage. Looking at commercial products Zircar Ceramics do a wide range with good strength, sustained max temperatures up to 1450 C and density down in the 0.3 - 0.5 g/cc range. This is probably an appropriate approximation.Did anybody estimate how thick the test tiles were?Heat shield tiles seem to be 35cm in diameter and 3cm thick, so volume of a tile should be 2387cm³ or 0.002387m³So around 10 tonne assuming 13 kg/m3 and 12 tonnes assuming 3cm of alumina silica tile. Consistent, and a lot less than I thought.For info, I’m assuming alumina silica because there was a job posting for a manager of alumina silica tile production.

Quote from: ThatOldJanxSpirit on 02/05/2020 04:21 pmQuote from: fael097 on 02/05/2020 03:41 pmQuote from: livingjw on 02/05/2020 02:43 pm- TPS weight trends. I would guess 10-13 kg/m^2 on average for windward side including fins. - What do you calculate for the fuselage and fin areas?JohnHalf fuselage has a surface area of 655m². I'm not considering raceway covers, shouldn't matter that much.Surface area of one side of a bottom fin is 42.11m² and top fin is 17.75m².So total heat shield area should be around 774.72m²Quote from: ThatOldJanxSpirit on 02/05/2020 01:52 pmA bit more digging on the ceramics. Bulk density is around 2.5-3 g/cc but this doesn’t take account of voidage. At the extreme these materials can be blown to 95% voidage. Looking at commercial products Zircar Ceramics do a wide range with good strength, sustained max temperatures up to 1450 C and density down in the 0.3 - 0.5 g/cc range. This is probably an appropriate approximation.Did anybody estimate how thick the test tiles were?Heat shield tiles seem to be 35cm in diameter and 3cm thick, so volume of a tile should be 2387cm³ or 0.002387m³So around 10 tonne assuming 13 kg/m3 and 12 tonnes assuming 3cm of alumina silica tile. Consistent, and a lot less than I thought.For info, I’m assuming alumina silica because there was a job posting for a manager of alumina silica tile production.Considering total TPS volume of 23.34m³, if you assumed 3g/cm³ (3000kg/m³) total TPS weight would be 69.72t. So shell, bulkheads and TPS alone would weight 121.32t already, above the targeted 120t dry mass. John's graph showed ~13kg/m² so that should include the necessary volume to given area. 10t seems right according to that graph, and it would result a total weight of 61.6t for shell, bulkheads and TPS. I'll consider that until we have better data on TPS density.