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When this technology can exist in space, earth will have orbiting shipyards building space craft.
by magoon 7y ago
When this technology can exist in space, earth will have orbiting shipyards building space craft.
- imglorp 7y agoIs this assuming some of the materials are available there? This would make sense if you're getting fuel or metal from asteroids, moon's surface, etc and building ships near those. But in Earth orbit, you'll need to lift the shipyard, then the fuel, then the metal powder etc for sintering, so what would be the gain?
- mkl 7y agoYes, you'd probably want to go get some asteroids. Even small ones can contain huge amounts of metals, and icy ones could be turned into fuel. There's a lot of potential, but it's all a bit out of reach for the moment. https://en.wikipedia.org/wiki/Asteroid_mining https://en.wikipedia.org/wiki/Asteroid_mining
- JoeAltmaier 7y agoIsn't moon dust mostly bauxite? (oxidized aluminum)
- mkl 7y agoNot exactly https://en.wikipedia.org/wiki/Geology_of_the_Moon https://en.wikipedia.org/wiki/Geology_of_the_Moon. I think the problem with moon resources is the moon's gravity while forming was strong enough to pull metals like iron and nickel down into the centre where we can't get at them (they're on the surface a bit too, but not conveniently concentrated). Asteroids, on the other hand, can contain lots of accessible nickel, iron, cobalt, etc. I'm no expert though!
- ben_w 7y agoWikipedia looks like it says [0], by elemental concentration, roughly 42% oxygen, 21% silicon, 12% iron, 8% calcium, 7% aluminium, 6% magnesium, 4% other. [0] Bar graph with insufficient labels: https://en.m.wikipedia.org/wiki/File:Composition_of_lunar_soil.svg https://en.m.wikipedia.org/wiki/File:Composition_of_lunar_so...
- imglorp 7y agoMagnesium should be even better for some space apps. In fact, it would sinter better in a vacuum than air. https://www.deepdyve.com/lp/wiley/sintering-of-magnesium-h06EgJZS7r https://www.deepdyve.com/lp/wiley/sintering-of-magnesium-h06...
- HeyLaughingBoy 7y agoStill, the concept of space mining is slowly becoming a thing: https://space.mines.edu/ https://space.mines.edu/
- adrianN 7y agoLifting many small things is easier than lifting one Battlestar Galactica sized thing.
- jacquesm 7y agoAlso, if it goes wrong the damage is limited, and likely fixable.
- mattlondon 7y agoYou could construct things that wouldn't fit inside the nosecone of a launch rocket if you assemble them in orbit. You could also repair/refit things without them having to go through re-entry and then be launched a second time E.g. replace damaged/worn out rocket cones or solar panels etc if you can build them in-situ. Imagine Earth-Mars shuttles that just go back and forth that would need maintenance
- alehul 7y agoOrbiting shipyards seems like a likely bet (assuming we want to explore and interact with space). If we want giant, heavy spacecraft that are capable of interacting with their environment — the space equivalent of a construction vehicle or a tank — earth's high escape velocity makes it impossible to launch from. We'd instead need to construct it in space, even if all the materials were from earth. As the cost of launching from earth continues to fall, it'll also become increasingly economically feasible to launch multiple payloads to build a larger, more complex spacecraft. (Think of the assembly of the ISS as a proof-of-concept here [1]). [1] https://en.wikipedia.org/wiki/Assembly_of_the_International_Space_Station https://en.wikipedia.org/wiki/Assembly_of_the_International_...
- ClumsyPilot 7y agoThe entire point of construction in space is to avoid launching from earth. It takes 36 times less energy to get a ton of material from moon surface, and can be done without rockets at all - a space elevator can be built on the moon with 'normal' materials.
- heavenlyblue 7y agoWhy is Elon Musk aiming for Mars if building a solar panel array and all of the subsequent manufacturing industry on the moon could potentially be way more productive? Is there something I am missing?
- chasd00 7y agoMusk has been talking more and more about the moon lately. Maybe he's thinking the same.
- whatshisface 7y agoThe fact that NASA has a clear directive to spend an absolutely humongous amount of money on the moon over a relatively short time frame may have something to do with Elon Musk's interest.
- rapunkill 7y agoHow will the heat dissipate if there's nowhere for it to go?
- rtkwe 7y agoHeat can still leave parts in space by radiating the heat away. We don't usually think about it because it's generally much slower than convective cooling here on Earth but it does happen and doesn't require a medium to cool. It's the method the ISS uses to cool its interior for example. [1] [0] https://en.wikipedia.org/wiki/Radiative_cooling https://en.wikipedia.org/wiki/Radiative_cooling [1] https://science.nasa.gov/science-news/science-at-nasa/2001/ast21mar_1 https://science.nasa.gov/science-news/science-at-nasa/2001/a...
- allannienhuis 7y agoright, but the rate of dissipation would be a huge problem for the additive technique described in this article. Plus the lack of gravity means that the molten metal would adhere to the existing component very very differently. Essentially it would mean designing the process from scratch - with almost no ability to test on earth during the design process. Not sure how effective computer modelling is for that type of thing :)
- rtkwe 7y agoYou can do small scale tests of each bit though: testing the sintered powder jet on a parabolic flight, test the heat dissipation in a vacuum chamber, etc. It wouldn't be easy but it's far from impossible.
- MisterTea 7y agoUnfortunately it's too slow. I work with electron beam welders so this is an everyday problem as it takes place in a high vacuum (1e-3 Torr or lower). Though for welding it usually isn't a big issue as most parts are large enough to sink their own heat. For deep high power welds in material which can't sink the heat we attach copper heat sink blocks to soak up heat like a sponge or for extreme cases, circulated oil cooled heat sinks. In space you can't vent to atmosphere or run the oil through a fan/water cooled radiator. So I'm thinking you'd have to build a heat reclaimer or high surface area radiator which uses an active cooling system like thermal pipes or circulated fluids like oil. But how does this adapt to different parts with odd shapes? Perhaps the printing would have to take place in a pressurized environment to facilitate cooling using gas and then figure out how to get rid of or recycle the waste heat.
- jvm_ 7y agoIf you turn on a blowtorch in space, does it need some sort of kylo-ren double-action torch to keep it in place? I guess it won't move if it's anchored to something, but that something will still move as the force is unbalanced?
- klyrs 7y agoProbably safer to tether yourself to the thing you're blowtorching...
- tantalor 7y agoWe are closer now that the ISS has a functional 3d printer (looks like PLA) https://www.nasa.gov/content/international-space-station-s-3-d-printer https://www.nasa.gov/content/international-space-station-s-3...
- honkycat 7y agoYou could manufacture goods ( electronics, cars, etc. )in space, and then drop them onto Earth. Free shipping!
- travisporter 7y agoThe reason relativity calls their rocket Terran 1 is they want to make “Ares 1/Luna 1“ someday :)