Humanity's Biggest Machines Will Be Built in Space (popularmechanics.com) 147
When rockets can no longer hold oversize payloads, building in space might be the best way to go. Popular Mechanics: Headquartered in Mountain View, California, Made In Space is working to make that dream a reality. For the past few years, they've operated the Additive Manufacturing Facility, one of the only 3D printers in space. While the AMF sits comfortably aboard the International Space Station, Made In Space has plans to launch a new printer that would operate exclusively in the vacuum of space. Their prototype, called Archinaut, is scheduled to launch later this year. Future machines like Archinaut will be able to print nearly everything in orbit -- where there's no limit on size. "We can manufacture a structure that couldn't support its own mass if it were on Earth," says Made In Space CEO Andrew Rush. "The only practical limitation you have is how much material you're providing to the system." The first Archinaut prototype is mostly just a proof-of-concept and won't be constructing mile-wide satellites anytime soon. "First you crawl, then you walk, then you run," says Rush. "We'll start out with manufacturing space-optimized trusses and booms and reflectors to provide a supply capability that we can't currently achieve." But once this tech gets off the ground, it can be used to build structures as big as their owners want them.
No gain until we get primary materia from space (Score:4, Insightful)
I fail to see what's the gain between launching a rocket with 1 ton of preassembled componned or 1 ton of materia used by a space 3D printer to build those component. And unless there's 0% loss during the 3D printer process, I would even say it's less efficient that way.
The only way I can see a real gain is if most of the materia weight come directly from space. For instance, asteriod mining.
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There are some designs that cannot be cut into 1-ton preassmbled components. The added utility of using such a design would have to exceed the losses in utlizing the Enormous Space Printer!(TM) if we want a net gain in efficiency.
The other side of this is that some steps in expanding infrastructure will always look silly if evaluated on their own merits instead of the longer goal that includes many more stages. If no one is willing to prospect asteroids until there is a facility to send the materials to,
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But as you say, not all improvements can be transferred to space. And perhaps far more significantly, a great deal of improvements for space can't be transferred to (or fully developed on) Earth. We've got to actually get out there and start experimenting, see how the theory translates to practice, and have ongoing incentive to improve freefall industrial techniques in order to see the sorts of advances we've seen on Earth.
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They're arguing that you're not limited by fairing sizes if you build in space, which is true. But then again, there's lots of ways to get around fairing size limitations. Here's one of my favourites: rollable composite trusses [youtube.com]. You can even have wiring, plumbing, flexible solar, etc rolled up with it. There's also self-deploying booms [youtube.com], retractable booms [youtube.com], etc. Whatever you have all is stored flat during launch, no thicker than the material's outer wall.
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...having flat-pack components that are expanded in situ
This will be a great human factors test: If astronauts can assemble structures in orbit from Ikea instructions, we are assured they will stay sane during a long voyage to Mars.
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Ya beat me to it, and by quite a while.
That's what I get for not refreshing before posting.
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"...or having flat-pack components that are expanded in situ..."
So the future of the space program is to be more like Ikea?
*ducks*
Re: No gain until we get primary materia from spac (Score:1)
My guess would be that the raw materials would be lifted to space in a far more efficient way. When the payload is rock and sand you can send it with a bigger boom.
Re:No gain until we get primary materia from space (Score:5, Insightful)
Think along the lines of large objects that could not be launched from Earth pre-assembled, especially items that have large empty spaces inside of them.
Also. you can assemble some items in space that would collapse under normal Earth gravity. Building in space, means that the object only needs to be able to stay together in micro-gravity, which gives you a bit more freedom in structural designs.
The current problem with mining materials in space is, we simply do not have the infrastructure in place to mine, purify and process minerals into finished metals in space. Sure it would be nice to see this some day, but in the mean time it's cheaper to launch your raw materials off Earth, especially if they're in the form of powdered metals, those pack very nicely into rockets. Besides I've heard there is some weird South African guy selling used discount rockets, not sure I'd trust him with my life, but with a pile of titanium powder, sure.
In short, you need to build the salt box pioneer shack in space before you build the steel furnace in space. We're barely past the salt box shack stage.
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>we simply do not have the infrastructure in place to mine, purify and process minerals into finished metals in space
We may not need to. There's considerable evidence to suggest that there's plenty of asteroids out there that are nearly pure iron - as in all we have to do is chop it up, hammer it out, or melt it down and cast/print with it. In fact, there was some research recently suggesting that most, if not all, pre iron-age iron tools were made from meteoric iron. Unlike earth-based iron deposits
Easy as pie (Score:3)
There's considerable evidence to suggest that there's plenty of asteroids out there that are nearly pure iron - as in all we have to do is chop it up, hammer it out, or melt it down and cast/print with it.
Oh is that all?
Do you have even the vaguest idea how hard and expensive what you just proposed actually is? What equipment do you plan to use? Because literally none exists or is even in development to do that. We don't have more than even the vaguest idea how we could possibly do industrial scale mining in the vacuum of space. We don't have the technology and won't for some time to come.
Even if 10% of the material is some sort of vacuum-hardening epoxy bonding agent made on Earth, you can still get 90% of your material from space.
Got any more made up statistics you'd like to cite?
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Got any more made up statistics you'd like to cite?
That you, in particular, will not be going out there. Musk and the Chinese have their own plans.
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I guess the word 'technology' has a quite special meaning for you? ...
We don't have the technology and won't for some time to come.
Yes we have. Since decades, half a century minimum.
There is no 'special technology, that does not exist yet' needed to fly a small craft to an iron asteroid, capture it and mine the iron: it is just extremely time consuming and so expensive it is right now not worth the efford.
Thats all
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No, we haven't had the tech since 1968. In 1968, we could not build an adequate robot miner, nor could we support a human in space that long. We're still trying to figure exactly how to send humans on long journeys outside Earth's magnetosphere, and even with that protection it's bad for the human. In 1968, we could have sent an object to an iron asteroid, and we could have gotten some data from it. That's about the limit.
There's also the question of what we do after we mine the iron to get it somewh
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You aremicing up technology with limits.
If you can put a human into space and land him savely on the moon and bring him back you have that _technology_
Extending that to an 18 month trip is still simply the same technology.
And yes, if we wanted we had robot miners around 1968, we just did not build them that time. What exactly do you think is so compicated about them?
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Nope, it certainly doesn't. And it will continue to not exist until people actually go try to make it - that's kind of the whole point of trying, isn't it? Nobody will ever develop micro-gravity mining or metallurgy processes here on Earth, they'd be completely useless.
As for doing anything on "industrial scale" - the solution is simple: we won't. Not at first. First we figure out how to do it, and then we figure out how to scale up. Just like we did with terrestrial technology. And that will be fine,
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Dude, free your mind. Rollers? Stampers? Molds? Pffft! Totally pointless. All of it.
The machine is in a VACUUM already. All that is necessary is to boil the metal and then spray it into whatever shape makes you happy. Sunlight, collected by mirrors and then focused onto a tiny spot would easily boil off the metal, then magnets would create a virtual "nozzle" to deposit it with micrometer precision.
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It's easy enough to create an oxygen-free atmosphere here on Earth - and yet we don't work metal that way here either. Perhaps there's a good reason?
First I assume you mean *melting* the iron, rather than boiling it - trying to precisely work with a gas tends to be a laboratory exercise, not an industrial one. Moreover, gaseous iron isn't magnetic, in fact the first magnetic gas was only discovered in 2009, and it was lithium cooled to within a billionth of a degree of absolute zero. And actually, molten
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There's considerable evidence to suggest that there's plenty of asteroids out there that are nearly pure iron - as in all we have to do is chop it up, hammer it out, or melt it down and cast/print with it.
And how do you propose to do that in a zero G environment? All those processes here on Earth depend on gravity. If you try to "chop" or "hammer" something in space, it doesn't work given Newton's laws of motions . Melting ore on Earth specifically requires separation of impurities to "float" to the top of the smelt based on densities. Casting requires pouring melt into a cast using gravity, etc.
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Of course it still works - nothing has changed except that you can't rely on gravity to hold your feet to the ground. We don't have decent gecko-grip boots yet, but there's plenty of cruder solutions. And for heavier work: power hammers and wood splitters have their own integrated anvils, it's not a complicated concept to adapt. Similarly, if you want to apply forces against an asteroid, you just have to fasten yourself to the ground first so that you don't just push yourself away instead.
Rule of thumb:
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And how do you propose to do that in a zero G environment? All those processes here on Earth depend on gravity.
What? Who told you that? You're off your nut. For example, the commonest way to cut large pieces of metal for industrial purposes today is the band saw. That in no way requires gravity. Even when the systems currently use gravity, there's no reason why they have to. For example, a hydraulic system might use gravity on earth to settle the contents of a return tank. But in space, you might use a low-pressure accumulator in place of the tank, to force the fluid into the pump inlet. Industrial hammering process
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What? Who told you that? You're off your nut. For example, the commonest way to cut large pieces of metal for industrial purposes today is the band saw.
Where in my post did I say anything about the most common way to cut metal. What I did say specifically is that in processing ore as the OP said "chop it up, hammer it out, or melt it down and cast/print with it" here on Earth requires gravity. Please show how none of those processes on Earth depends on gravity.
That in no way requires gravity. Even when the systems currently use gravity, there's no reason why they have to. For example, a hydraulic system might use gravity on earth to settle the contents of a return tank
A hydraulic system that handles molten metals. Sure that's very practical in zero G.
But in space, you might use a low-pressure accumulator in place of the tank, to force the fluid into the pump inlet.
Again for fluids at room temperature it's not a problem. We are talking about molten metals here.
. Industrial hammering processes use far more force than is provided by gravity; they are done with steam, or hydraulic force. Gravity is old hat, nobody has time to wait for hammers to fall.
How would hydrauli
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The machine is in a VACUUM already. Build anything you want with vacuum casting. All that is necessary is to boil the metal and then spray it into whatever shape makes you happy. Sunlight, collected by mirrors and then focused onto a tiny spot would easily boil off the metal, then magnets would create a virtual "nozzle" to deposit it with micrometer precision.
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All that is necessary is to boil the metal and then spray it into whatever shape makes you happy.
The problem is not that you can't heat ore. The problem with processing ore is separating out the impurities. In the exact example, chopping, hammering, smelting are ways here on Earth to remove impurities from metals like iron. They rely on the fact that gravity is assumed. Can you devise other processes which do they same thing but do not rely on gravity, yes. But you can't rely on those processes.
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And how do you propose to do that in a zero G environment? All those processes here on Earth depend on gravity. If you try to "chop" or "hammer" something in space, it doesn't work given Newton's laws of motions . Melting ore on Earth specifically requires separation of impurities to "float" to the top of the smelt based on densities. Casting requires pouring melt into a cast using gravity, etc.
As far as chopping up, there are multiple ways it might be done. Centrifugal force or held in place by blowers as incarcerating said asteroid inside a structure would probably be a requirement, although they might just attach a hard point to place such digging equipment on the item to be worked into smaller bits itself. Still, most ideas go more towards the smelting process which the leading proponent is the Mond process where using heated carbon dioxide can turn nickel and iron (IIRC) into gasses at variou
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That's right. been a while since I've looked into it. Energy practicality depends on how solar panels are looking in that time frame. ( Perhaps 50-100 years for testing prototype systems if we're lucky by my reckoning. ) If construction of a suitable window is possible, just direct sunlight concentration by a mirror array. My thinking was the target is contained, floating in the middle, kept in place by several possible methods, and first outgassed by heating it up. Then Mond process forms the liquid witch
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This presumes that you want to make EVERYTHING out of iron, and not steel(which needs further processing, you know). I'm not even sure if most of our modern steelmaking techniques would work in zero-g. Pure iron on its own isn't really all that useful, generally its too brittle witho
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Not at all. All it assumes is that making things out of iron would be useful. More sophisticated alloys and manufacturing techniques would undoubtedly be developed too - but we have to start somewhere, and iron is an incredibly useful material just as it is, and far easier to work with when we're just starting out.
As we expand into space, it makes sense to pick the low-hanging fruit first. Bulk construction using iron, radiation shielding using "cemented" dust and gravel, and rocket fuel from water - the
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They're talking about size. 100,000 tons of material can be sent in multiple launches but a 100,000 ton machine is too big to send. Of course at 10,000 dollars per pound it's too expensive to send too at current costs to send a payload into orbit. Of course they're working on that. Most Sci-Fi authors envision using asteroids to mine for materials instead of boosting it out of a gravity well. Maybe my great grand children will live to see it.
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Some people think SpaceX's BFR may get costs to LEO down to $10/kg.
If my math works out, that gets your 100,000 tons of material in LEO for $900 million (transport costs only). Using BFR's estimated 165 tons/launch to LEO, that's about 600 trips.
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Because, like TFA says, you can build things out there that couldn't even support their own weight on earth - that opens the possibility of radical designs that might limit the usefulness of pre-assembled parts. It's an optimization problem with different trade-offs depending on what the capabilities and inefficiencies are of building things in space versus building things planet-side and launching them. For instance, I could imagine that building a giant antenna or solar array would likely benefit from us
Flexibility and cost (Score:5, Insightful)
I fail to see what's the gain between launching a rocket with 1 ton of preassembled componned or 1 ton of materia used by a space 3D printer to build those component.
The 3D printer doesn't require you to decide what to make with it prior to launch and it allows you to skip the delivery lead time for a product which could be substantial. Otherwise you are correct. You probably would need some sort of 3D printer like technology to manufacture a lot of stuff in space simply because a lot of the manufacturing techniques we use on earth simply wouldn't be viable due to supply chain issues and the need for compact and flexible production equipment.
The only way I can see a real gain is if most of the materia weight come directly from space. For instance, asteriod mining.
Asteroid mining is an idea that won't happen for a very long time. There are several huge obstacles to it including: 1) The fact that we don't have any mining or refining equipment that is space worthy nor any reasonable prospects of getting such equipment anytime soon. 2) The extravagant cost of getting the equipment (which again we don't have) to the asteroid and doing useful work with it. 3) Most useful products require multiple materials/components which cannot be sourced from a single asteroid even if it were financially viable to do so. For a long time to come it's going to be a lot cheaper to launch stuff from earth than to mine it from an asteroid.
Also the biggest obstacles actually are not material weight. We just haven't addressed the hard issues because it's SO expensive to get to orbit that they haven't been worth worrying about. But even if you drop cost to orbit to zero, the cost of building the technology and infrastructure to manufacture in space will likely dwarf even the current launch costs. Think of it this way. Ford builds cars and one of its assembly plants costs north of a billion dollars to create. That is just for final assembly. The cost of the production facilities and parts to build the product in its supply chain easily costs 100 times more than that (there are about 30,000 parts in a typical car). And we have proven and well developed sources of raw materials. All that to build a product we know how to make with proven technology we can manufacture with economies of scale. Making something the cost and complexity of cars in space at any sort of scale would cost a large fraction of the world GDP for the foreseeable future.
Space based manufacturing is arguably a worthwhile goal but we need to be realistic about how long it will take to make it economically viable.
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So getting enough materials into LEO to duplicate the largest machine currently built would cost (100,000 tons)*(1000 kg/ton)*($4000/kg) = $400 billion. Never mind the cost of fabrication and assembly.
There are many silly ways to look at this nonsense (Score:2)
If we stick to ships, the Prelude [wikipedia.org] is six times larger than the Allure of the Seas in displacement at 600,000 tons and covers an area around 5 times that of the International Space Station at 450 tons.
This mismatch in weight vs size is the somewhat lame point the article's premise is based on.
I could change the equation dramatically by talking about the size of a blimp versus the ISS. The Hindenburg had a footprint larger than the ISS, weighed half as much, and enclosed more than 200 times the volume.
Also, c
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The largest ship [wikipedia.org] has a displacement (weight empty) of 100,000 tons. I'll ignore buildings since TFA is talking about machines. Current launch costs to LEO [quora.com] bottom out at about $4000/kg, though it could drop to $2000/kg in the near future (have to see if Falcon Heavy's costs hold up). So getting enough materials into LEO to duplicate the largest machine currently built would cost (100,000 tons)*(1000 kg/ton)*($4000/kg) = $400 billion. Never mind the cost of fabrication and assembly.
By my impression, when they mean largest machine, they are talking dimensionally rather than mass. They are talking about building a cube out of truss that is 5 kilometers to a side. Even adding diagonal crossbeams for support, it might only be a fraction of the mass of that ship.
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Why would you want to build cars in orbit? You'd start with structural materials. Likely that would involve scooping up lunar regolith and smelting it to make iron, aluminum and magnesium (and oxygen, which you want too). Electric bulldozers and solar smelters should work fine on the moon. You'd use those to make structural beams, hulls, whatever you can, shipping up everything else from Earth.
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Space mining and ore processing has major advantageous over earth bound processing. The first is the ore's aren't all oxygenated from earth's atmosphere, this means iron can be found in its raw form rather than the iron oxide that exists on earth. One of the biggest challenges in processing ore on earth is getting all the oxygen out and getting back to the raw metal.
Another major advantage is that you can melt that ore with essentially a big magnifying glass and you have much longer to shape it because you
Hideously expensive and hard (Score:2)
Space mining and ore processing has major advantageous over earth bound processing.
It POTENTIALLY has advantages. It also has a lot of disadvantages. We know some of each and there undoubtedly are a lot of advantages and disadvantages we have yet to learn about. Most of the conjecture I read here on slashdot is the sort of uninformed musings you get from a science fiction story rather than evidence based engineering. What is 100% clear however is the economics of doing this which are hideously expensive and will remain so for a long time to come. There are technical obstacles that pr
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The key part for TFS is:-
"We can manufacture a structure that couldn't support its own mass if it were on Earth"
In such a case, it couldn't be preassembled on Earth as it would collapse.
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structures that would not survive launch G's would be the obvious answer. You can 3D print something that is 80% empty that is perfectly acceptable as a beam or truss for space construction.
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I fail to see what's the gain between launching a rocket with 1 ton of preassembled componned or 1 ton of materia used by a space 3D printer to build those component.
The major gain is self sufficiency. What is the current process today if a part breaks on a station like the ISS? The best case scenario is that there is a spare part already on the station and that it can be replaced right away. However, the station doesn't keep a spare of every single part and they have to wait until the next launch to replace it. That could be a minor inconvenience or a major problem depending what part needs to be replaced.
The second gain is that some parts can be fabricated that are to
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Actually, the CHEAPEST and best long-term supply of base-materials is from the moon . . . using a mass-driver system (electric driven from solar power) to deliver as much material as needed ANYWHERE in the earth-moon system.
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The James Webb telescope isn't much bigger than the 1948 Hale telescope. One of the things that makes it remarkable (and expensive) is that it folds up small enough to fit in a fairing for launch. If you could build one in space from raw materials you could make it enormous.
Living volume in space is pretty cheap in terms of materials. So why is it so cramped in the ISS? Because all those modules had to fit into fairings for launch. There are proposals to manufacture enormous stations in orbit basically
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Anything built on earth needs to be able to cope with 9.8m/s^2 acceleration.
Their premise is that building in space allows for sparser construction.
You may be able to reduce the overall amount shipped from Earth to space and save money overall (not saying it will work, but that seems to be their premise).
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Pretty much this. Stupid idea other than as a partial proof of concept in vacuum. Mass is mass.
Though I suppose if the 3D printer were designed in such a way as to use a dense mass as material, then inject gas to create essentially foam extrusions of such dimensions it would be unwieldy to launch. Anyway you'd still have to get the gas up there as there is literally nothing to work with.
Now if you could get a 3D printer to the moon, that is able to mine material, convert it to usable printing material, and
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Nope. Drop your socket, and it slowly starts do drift away from where you let it go. As long as you don't actually throw it away from you, it will remain nearby for quite some time. And since you can't throw fast enough to appreciably change its orbit, the only way it's on a decay orbit to Scotland is if you were already on that path yourself.
Heck, it doesn't even have any differential in gravitational acceleration to power it's rolling underneath to the exact center of your space-car like it inevitably
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Nope, but a good impact wrench already does a better job anyway. Just need to make sure you fasten yourself to the car first, so that it doesn't just send you spinning instead. Gravity is really convenient, but it's not irreplaceable.
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WORSE CASE - drop my 10mm socket . . . and watch it return in a couple of years in a drift/altered gravitational differential, magnetic bias, solar wind offset, etc.) orbit at 10K(+) MPH to blow through my habitat like a micro-nuke ! ! !
Our Greatest Achievements (Score:2)
Makes sense (Score:4, Funny)
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No duh. Where are we going to build our first dyson sphere? In the middle of Kansas?
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It is always easier to build things in space.
Obviously not. But, at some point it will become easier to build some things in space, especially things that can't be built in a gravity well at all. Automated orbital factories are a long way off, but an orbiting 3D printer is a big first step down that long road.
Just like living on Mars. It is so much easier than living on Earth.
Now you're just making shit up. No one with half a brain has ever made that claim.
And now we have AI which makes it even easier.
The sort of AI we have now probably does make some things easier, though I don't claim to know what. The sort of AI we will eventually build will definitely make th
1) Build 3D printer, 2)..., 3) Profit! (Score:2)
When rockets can no longer hold oversize payloads, building in space might be the best way to go.
Naturally but kind of skipping an important step there. You also have to be able to supply materials in space including raw materials and the production equipment and the power source(s). Whether shipped from earth or mined from other planets/asteroids, you don't get to skip the step of having rockets deliver the machines and power source and the materials to be able to manufacture in space. It's going to be a lot more complicated than shipping even a very clever 3D printer. Actual assembly work is the
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Or they're just working on one part of the overall problem - the printer.
Which is fine but then don't give me a bunch of ridiculous PR about building giant structures in space when that isn't likely to happen within the lifetime of anyone reading this. Just say they are working on 3D printers in space which is sufficiently cool by itself.
How it gets supplied with raw material is another issue for someone else to solve, but there are multiple options there.
No there are not. There is precisely one option currently and for the reasonably foreseeable future which is to supply from Earth via rockets. The notion of mining resources that didn't come from Earth simply isn't going to happen for many de
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The notion of mining resources that didn't come from Earth simply isn't going to happen for many decades to come even under the most optimistic of assumptions. I'd love to see it happen but I don't honestly expect to see it before I die.
People said the same thing about putting people on the moon in the years prior.
They were wrong then too.
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"Persevered for centuries. It literally took centuries for our technology to get where it is. There is no rational reason to believe it will not take more centuries to get to the point where space based manufacturing is economically viable."
Yes, there is. Technology development has been exponential, not linear.
In terms of mining in space, you don't even really need to invent that much. There are some engineering problems to work out, but nothing that really looks like it would be terribly difficult. It r
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Hmmm, I know that we currently have no materials or processes for making a material strong enough for an Earth "space elevator" - it would need something like a fibre with the tensile strength of diamond, in a really light high-strength epoxy. And we don't have a process for making diamond-strength fibre in millimetre lengths, let alone multi-kilometre lengths.
But a lunar "space elevator" - with abou
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Seems like I'm always talking to the deaf, but GO TO THE MOON - LOTS of silicon ===> LOTS of solar cells ===> LOTS of power.
A basic rail/mass-driver can deliver any amount of raw materials (or even REFINED materials) anywhere in the earth/moon system (and BEYOND). The most rudimentary crude AI-driven scoop/heat/refine machinery can be turned into a quasi-von neuman solar cell factory - - - placing power-generating panels end-to-end, side-by-side, EVERYWHERE, and providing the energy needed to power a
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There's just as much iron in regolith as there is aluminum, so you get iron too. And also loads of magnesium, which is itself a pretty useful material.
As every Star Trek fan knows... (Score:2)
Big space stations and starships would have to be built in space due to the gravitational benefits. That also would tend to leave them unable to land without massive damage entering the atmosphere, unless they are able to separate into distinct sections, one of which could have the necessary size and shielding.
To me, the real question is whether or not our species will destroy itself, or get stuck in a cyberpunk-style corporate dystopia, before getting a chance to create a society like the Federation.
Space catapult (Score:2)
One of the big arguments against the use of a rail-gun like space catapult is that cargo and humans would not survive the acceleration needed. Raw materials, on the other hand, could.
Just how far can you chuck a pumpkin?
Space Elevator (Score:3)
Use the moon for materials. (Score:2)
On smaller scale projects in earth orbit, the raw materials could be rocketed and orbited to the manufacturing site as we do now. Sooner or later though, the cost of hoisting large megastructure masses to orbit could be prohibitive. If the raw materials were to come from space, then asteroid mining is a hypothetical idea, but it seems to me to have too many practical and economical limitations in this nascent concept stage. So, what about the moon? Here is a vision for the not too distant future.
Whateve
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yes use the moon but why waste time printing? big things can be built with sheets and beams of metal smelted with solar energy.
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Good point, and true. But as others have also pointed out, some things are best manufactured on orbit, such as a mile long lightweight truss that would not do so well at the surface with gravity induced bending moments.
in space, isn't cooling a larger problem? (Score:2)
Given the vacuum insulation around everything, isn't cooling a much larger problem in space than on earth? Given the problems of heat dissipation on earth, wouldn't they be worse in space?
Second issue is speed. Speed of light is an issue for signal propagation across circuits in today's computer design -- if the idea is to create larger machines in space, won't that get worse?
Biggest machines in space (Score:2)
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This would also be a good way to control how much radiation from the Sun reaches Earth's surface.
If you really need to that quickly and cheaply sulphate aerosols seem like a very promising option.
https://www.ted.com/talks/david_keith_s_surprising_ideas_on_climate_change [ted.com]
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Fun getting that right as large releases of sulphate aerosols have often resulted in a few years of famine due to the global cooling. One example I came across the other day, https://en.wikipedia.org/wiki/... [wikipedia.org]
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If they come from a volcano you've got no control over them. If you're pumping the sulphates with technology you can just turn down the flow rate.
You'd have some sort of international body which decided on what the flow rate would be. Kind of the Fed sets interest rates, except it would global and deciding whether to pump more or less.
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Oh, it's possible and worth considering. The problem is that climate science deals a lot with chaotic systems. Sorta like hydrology (or whatever you call studying river flows or ocean currents). You can dump rubber ducks in a river and have a high confidence that most will end up downstream, but it is hard or maybe impossible to predict the route of an individual duck or whether it'll even arrive. Ocean currents are even harder, look at the friendly floatees, https://en.wikipedia.org/wiki/... [wikipedia.org] climate scienc
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Oh, it's possible and worth considering. The problem is that climate science deals a lot with chaotic systems.
Like the economy. In the UK there's a Monetary Policy Committee which sets interest rates based on looking at all the data.
https://en.wikipedia.org/wiki/... [wikipedia.org]
If you had something analogous for climate control they'd look at all the data for he last year, try to work out what events might alter climate for the coming one (El Nino) and set the flow rate. If there was a volcanic eruption they could decide to change things at the next meeting.
In fact that's one advantage to controlling temperature via a sulphate
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Interesting, thanks. I am surprised they are talking about so little aerosols. And they would have to be maintained or increased as industry cleans up.
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Even if you solve the 'Mr Burns blots out the Sun' problem (make most of it out of glass maybe) you run into at least two biggest problems of a Dyson sphere
Gravity, not Thermodynamics is the Problem (Score:1)
The laws of thermodynamics prevent this from happening.
No, they do not: they just require that the system to do build such a sphere expends energy. The rate of expenditure will determine how rapidly you can build the structure. something this large would require a huge amount of energy to construct but, if you are willing to let the process take long enough the actual power required can be small.
However, beyond the impracticality of construction on a human timescale with current technology a planetary dyson sphere is an absoutely appalling idea for the Earth be
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The ringworld is unstable!
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We'll just retcon some thrusters and for good measure, a laser propulsion for the Sun, I mean Earth.
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There are a LOT of potential energy sources in space that simply cannot be found and/or utilized on earth. Most are still out of our technical grasp, but solar isn't, and is pretty damn effective in space... even more so closer to the sun.
Re:Planetary Dyson Sphere (Score:5, Informative)
Energy storage alone would eat up most of the bonus you get from zero-G.
Why would you need to store energy? The lack of atmosphere means the sun is twice as bright, and it doesn't set. There is no "night" in space.
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Never heard of an eclipse?
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You are aware that 'the laws of thermodynamics' are to describe steam engines and other heat machines and have no application in space travel? ...
The rest of your post is completely bollocks
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The laws of thermodynamics apply everywhere. There are indeed energy requirements for what is proposed, and I would recommend staying within a few AU of, say, a G-class star in order to gather the energy.
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I suggest to google "law of thermodynamics" and read the relevant wikipedia articles before you make even more an idiot about your self.
Hint: thermo! What does thermo mean? hu?
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Space is big, dude. Do you know how many paperclips you can make out there?
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You don't want to build large structures in near Earth orbit anyway. Tidal forces would require substantially stronger structures than would be necessary farther from a gravity well. Also, even the small amount of atmospheric friction there would require you to periodically boost your structure back into a higher orbit, and the fuel cost for large structures would be prohibitive.
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It's already a junkyard in near earth orbit.
We can clean up LEO with a laser broom [wikipedia.org].
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I've wondered about the possibility of launching giant expanding foam cans into LEO and squirting it out. The foam is low density, high cross-sectional area - perfect for objects to collide with, altering their velocity in a way that will probably result in burn-up. Then the foam, being highly susceptible to even the tiniest atmospheric drag, de-orbits in weeks to months. It'd be silly to try to sweep all of LEO that way, but still curious just how infeasible it is.
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NASA has used aerogel to capture micrometeorites.
Your foam idea would require a spaceship to rendezvous with each object. Fuel consumption would be uneconomical. A ground based laser would be way cheaper.
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I wasn't thinking big objects. I was thinking the tens of thousands of tiny paint flecks and metal shavings.
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Or a giant bat-shaped structure that centers itself in front of a full moon.