6 ms·
Dad joke: "They'll go at night" But really, it's cool that they're using carbon-carbon protection similar to that which was originally developed for the leadin
by chiph 8y ago
Dad joke: "They'll go at night"
But really, it's cool that they're using carbon-carbon protection similar to that which was originally developed for the leading edges of the Space Shuttle. And I really want to know how they built foamed carbon for the interior.
I'm guessing that they're using white ceramic paint on top instead of a reflective foil shield (like the Webb uses) because the foil would be shredded by the solar particles.
- thedancollins 8y agoTexas A&M, represent!
- kijin 8y agoI'm curious about the foam, too. Normally, foam contains a lot of air. But that kind of foam will blow itself apart in a vacuum. How do they make foam where all the air pockets are replaced with vacuum? Is vacuum-filled foam a better or worse insulator than air-filled foam?
- noir_lord 8y agoI think it would be better if it was vacumn voids rather than air filled since air will conduct heat via conduction.
- rubatuga 8y agoFoam can be made and slowly evacuated. Vacuum filled foam is a better insulator
- jstanley 8y agoIt could be open-cell foam instead of closed-cell foam. In earth atmosphere the cells would still be filled with air, but the air would be able to leave without blowing the foam apart.
- dghughes 8y agoAnd if the foam cells have a vacuum in them (in? lack of?) how does it not implode when on earth.
- noir_lord 8y agoThe difference between Vacumn and 1atm is 14psi, bike tires pumped to between 50-120psi (on my road bike for example), 14 psi isn't that large a pressure for a reasonably strong/stiff material.
- dghughes 8y agoI know what you mean but in a way I think there is a difference since the material has to withstand inward pressure; compressive forces. A tire/tyre rubber has tensile strength, most (all?) pressure vessels on earth are tensile. It seems odd the difference between compression and tension when it comes to certain forces. Anyway, I just though it would matter.
- deleted 8y ago[deleted]
- reaperducer 8y agoNormally, foam contains a lot of air. But that kind of foam will blow itself apart in a vacuum. In the video, Thermal Protection System Engineer Betsy Congdon says it's 97% "air." I can't say whether it's actually air, or she's simplifying things for the general public or not. She also says twice that "water" is used in the radiators. But I'd have to believe that NASA's using something that absorbs/dissipates heat a little more efficiently. Perhaps whatever it is will end up in desktop gaming rig cooling systems eventually.
- zaarn 8y agoThey used deionized water, not unusual for gaming rigs either. The temperature range is about 15C to 125C, at high pressure this is most ideal for use with water and water itself is a rather good coolant.
- petre 8y agoThe only substance that can transport more energy than water that I know of is ammonia. But it's quite corrosive and it has to be pressurized at 50-100 bar to make a difference.
- ofrzeta 8y agoSpeaking of jokes, I guess this is how they make the foamed carbon: https://www.youtube.com/watch?v=Wex_yKfrTo4 https://www.youtube.com/watch?v=Wex_yKfrTo4
- Nokinside 8y agoI wonder how much carbon foam insulation costs. http://carbonfoam.com/ http://carbonfoam.com/
- Taniwha 8y agoWell essentially they are going at night, bringing their own night with them