Asteroid Mining; Is it necessary?

[FenrirWolf]

If water's the main objective, might as well mine a comet. They are big chunks of ice flying around the Solar system, after all.

It's probably easier to catch up with a near-earth asteroid vs a comet. Those suckers are plummeting towards the sun from the Oort cloud and matching orbits with it would be pretty fuel-intensive

[Langkard]

rare earths aren't as rare as you think they are. pretty much every rock on the planet has them. its just a matter of at which concentrations are most valuable (most material for the least cost). when the rich deposits are gone we will just move along to the less rich ones, start reclaiming landfills, employ extreme recycling means. all this stuff will happen long before getting them from asteroids becomes cheaper.

I didn't say rare earth elements are rare. That is just their name. You do understand that, right? They are, however, expensive because of the processes needed to extract them. Finding deposits that can be readily extracted is difficult and, in the case of the heavier rare earths like dysprosium, are produced entirely in China. Other sources around the world produce the lighter rare earths like praesodymium. China still produces 90% of all rare earths and 100% of the heavier ones. China also periodically attempts to limit their export, which then causes prices to rise. As demand increases, other sources need to be found. A current prospect is ocean sediments, particularly near ocean vents. Mine tailings from the old mining of heavier elements like uranium also are a source of rare earths, as well as possible recycling of things like old electronics. But, for now, those sources are all for the lighter rare earths - relatively abundant. The heavier rare earths remain a Chinese monopoly unless someone finds another source. That means that asteroid mining may indeed end up being cheaper than any earthly prospects. And still safer, when the environmental costs of rare earth extraction and recycling are factored into the price.

[Nuke]

my main point is that the high yield deposits will last a really long time. even the moderate yield deposits will be more economical than asteroid mining. the only reason china dominates right now is that they severely undercut the market back in the 90s. but china started getting greedy and limited export to artificially inflate the prices. as a result it is now economically viable to open mines elsewhere. there are a lot of rocks on the earth.

[p331083]

Are we actually running out of any elements or compounds which are abundant in asteroids?

Doubt it. As the prices of raw materials increase it opens up new previously unprofitable sources up. Combine that with advances in technology of resource collection and we wont be running out of the vast majority of raw material for a long time.

[Seret]

As the price rises it also becomes profitable to do more clever recycling. Apparently it's already viable to extract metals from catalytic converters out of road sweepings, for example. So much of what we've already mined will go around again. It'll have to really.

[RuBisCO]

I don't agree that the choice is either asteroid mining or a stagnant economy, if that's what you're saying.

No no that is not what I'm saying, Its stagnant economy, there is no other option, asteroid mining is not a solution.

[Seret]

No no that is not what I'm saying, Its stagnant economy, there is no other option, asteroid mining is not a solution.

Why do you think a stagnant economy is inevitable?

[magnemoe]

my main point is that the high yield deposits will last a really long time. even the moderate yield deposits will be more economical than asteroid mining. the only reason china dominates right now is that they severely undercut the market back in the 90s. but china started getting greedy and limited export to artificially inflate the prices. as a result it is now economically viable to open mines elsewhere. there are a lot of rocks on the earth.

This, one problem with raw materials is that its not economical to have mines who are too expensive to be competitive running and it takes time to open mines.

Asteroid mining require far more space infrastructure. I belive it will come but from the other direction, first you start mining asteroids for water who can be made into fuel.

This is very valuable in orbit and is used for the LEO to GEO run, Moon and later asteroid missions. next you want minerals for use in space for structure and shielding, at this point it might be interesting to extract expensive minerals for return to earth.

[sgt_flyer]

Well, if they can set up automated factories and mining bots, (maybe in the asteroid belt) they should be able to build some crude return vessel to return the raw materials. (They might even not need parachutes - just a shield to survive reentry, as raw materials won't be annoyed as much as humans / delicate electronics by an impact at terminal velocity after maybe several aerobrakes)

Once they can make regular shipments, it's not really a problem if the trip back to earth takes two years - when you send the return vehicles every 6 month or year while the others are in transit.

Nevertheless, i think they might try to set up sooner mining ops on the moon before than asteroids. (Lots of lithium and other elements there, + gravity and a means to dissipate heat more easily (through the ground itself)

From there, you might just need a fixed mass driver to send the shipments back to earth, in a container capable of surviving reentry. (The return vehicle might even not need electronics)

Edited March 30, 2014 by sgt_flyer

[Seret]

I wonder how much processing would need to be done at all in the asteroid belt? It might be cheaper to move them to Earth and process here. The difficulty here is that it's all down to practical decisions, but we don't have any data for what the actual variables would be at some random point in the future. So it's impossible to say anything particularly coherent IMO.

[sgt_flyer]

Well, the mining systems / spacecrafts would need to process at least enough to keep them running - eventually scale up, without needing to send up new mining spacecrafts directly from earth. (If they use unmanned mining systems) this would make things much cheaper if all you need to send from earth would be a regular shipment of the control circuits for the mining systems built there

[CaptainKipard]

Well, if they can set up automated factories and mining bots, (maybe in the asteroid belt) they should be able to build some crude return vessel to return the raw materials. (They might even not need parachutes - just a shield to survive reentry, as raw materials won't be annoyed as much as humans / delicate electronics by an impact at terminal velocity after maybe several aerobrakes)

Lol I imagine special impact zones for that kind of stuff. They'd need very good mathematicians to make this work safely.

[jwenting]

Well, the mining systems / spacecrafts would need to process at least enough to keep them running - eventually scale up, without needing to send up new mining spacecrafts directly from earth. (If they use unmanned mining systems) this would make things much cheaper if all you need to send from earth would be a regular shipment of the control circuits for the mining systems built there

and when there's a decent number of those circuit boards needed it'll be cheaper to build a factory in orbit. Can also make other boards and ship those back to the surface.

[RuBisCO]

Why do you think a stagnant economy is inevitable?

aah do you want me to go over the numbers again on how silly it is to expect use to keep growing? 300 years until we consume more more energy then sunlight hitting the earth, 1000 years until we consume more energy then the sun outputs, ~2000 years until we consume more energy then every star in the galaxy, you want me to keep going? Eventually the growth rate has to go to zero because we won't be able to physically grow anymore.

Edited March 30, 2014 by RuBisCO

[drakesdoom]

Once you can manufacture in space why ship anything back to earth? There is plenty of rock down here already, and as soon as the first self sufficient space colony is up planet surfaces become backwater.

[Seret]

aah do you want me to go over the numbers again on how silly it is to expect use to keep growing? 300 years until we consume more more energy then sunlight hitting the earth, 1000 years until we consume more energy then the sun outputs, ~2000 years until we consume more energy then every star in the galaxy, you want me to keep going? Eventually the growth rate has to go to zero because we won't be able to physically grow anymore.

Right, I see you're equating economic growth with energy demand growth in a strictly linear fashion. That's not an entirely unreasonable simplification, but it turns out that reality is a bit less straightforward. As I mentioned back in my original reply to you energy use does decouple somewhat from economic growth in industrialised economies.

At the very least what happens is that countries get more efficient at squeezing more economic growth out of small increases in energy use. For example the UK (the first country to industrialise) managed to improve their Energy/GDP ratio by a factor of three between 1880 and 1990. So they were getting three times more economic growth out of the same rise in energy demand. And growth can indeed be had completely for "free", Denmark's GDP increased by 50% between 1977 and 1999, but primary energy consumption didn't rise at all. Efficiency is a good thing!

Generally what happens is that energy intensity (ie: energy demand per unit GDP) does rise sharply as nations industrialise, but the biggest peak was the UK and every nation since has showed a smaller peak (they benefit from improvements in efficiency). After that the trend starts to reverse due to a lot of complicated factors (de-materialisation of industry, growth of a service sector, etc) and completely decoupled economic growth can and does occur.

So no, projecting a flat ever-increasing energy use due to economic growth isn't really realistic. Energy demand just doesn't track economic growth like that.

[Nuke]

I wonder how much processing would need to be done at all in the asteroid belt? It might be cheaper to move them to Earth and process here. The difficulty here is that it's all down to practical decisions, but we don't have any data for what the actual variables would be at some random point in the future. So it's impossible to say anything particularly coherent IMO.

since only a small fraction of the mass of the ore is useful, it would be more efficient to do the ore processing in place, and ship back the refined materials. unless of course you somehow find a way to use the useless material for propellant.

[Seret]

since only a small fraction of the mass of the ore is useful, it would be more efficient to do the ore processing in place, and ship back the refined materials. unless of course you somehow find a way to use the useless material for propellant.

Fuel efficient yes, but economical? Who knows?

I was just thinking out loud really. Yes, moving lots of useless mass is expensive, but so is sending processing infrastructure into space. Like I said, we don't have enough information to say how the numbers actually add up.

[CaptainKipard]

Right, I see you're equating economic growth with energy demand growth in a strictly linear fashion.

Don't forget that the kind of economic growth we've seen so far is not sustainable, since by it's very nature it relies on population growth and loans being taken out.

Who knows that money is being made out of thin air, by simply creating a loan?

[Stargate525]

unless of course you somehow find a way to use the useless material for propellant.

Pretty easy: Fire it off the back of your ship.

[Seret]

Don't forget that the kind of economic growth we've seen so far is not sustainable, since by it's very nature it relies on population growth and loans being taken out.

Lot's of things we do today aren't sustainable long-term. That doesn't mean that economic growth itself is unsustainable, just that future growth would have to be derived from different things.

Economic growth does not rely on population growth btw. The richest countries in the world all have the lowest rates of population growth.

Who knows that money is being made out of thin air, by simply creating a loan?

Money is made of thin air. It's an idea, not a real object. We attribute value to things for entirely arbitrary reasons sometimes. It's about attitudes, emotions and even fashions as much as any kind of intrinsic value.

[Nuke]

and when there's a decent number of those circuit boards needed it'll be cheaper to build a factory in orbit. Can also make other boards and ship those back to the surface.

i kinda have a pcb lab in my room. it really doesnt take that much stuff. its going to be the raw materials thats the problem. copper being the big one (ceramics, glass, polymers, lead, tin, and alluminum production help too).

pcbs are just copper fiberglass and epoxy (i just buy un-etched stock, in space you need to manufacture this). an etch resist mask is applied and the unmasked areas are dissolved in ferric chloride. the board is then silk screened with an epoxy resin. vias are created with an electroplating process. pads are then tinned. after that you can do reflow soldering to attach all the parts. many of these steps can be done by hand, but machines exist to speed things up. you need lots of water and several chemicals (the number of which depends on your process, i get by with just 4). components need more sophisticated factories to manufacture. but many of them are tiny and so light it might just be one of those things thats economical to fly up from earth. 10 pounds of parts can build a lot of stuff.

id worry about basic materials production at first. blacksmiths on the moon would be a good place to start.

[Seret]

i kinda have a pcb lab in my room.

Real chip foundries are somewhat more complicated than this though. You're not exactly sputtering and doping your own silicon at home I assume? They're large factories with billions of dollars worth of extremely complicated precision machines. The cost and complexity of chip foundries is the main force that is working against further advances in processor speed. Basically we only get faster chips if the eyewatering cost of their production can be overcome enough to make them viable economically.

You'd never build electronics in space. Like you say, they're small and light but they do require huge infrastructure to fabricate. You'd just build them on Earth and ship them up.

Edited March 30, 2014 by Seret

[Nuke]

fabs are a different matter entirely. even the passive components are less than trivial to manufacture. i can make the boards but i still have to buy the parts. but you are still right. we need the basic materials before we even think about doing more complex production. we cant even build structures without landing a bunch of prefabs buildings yet. ye ole moon smithe shop needs to be built out of bricks (one of those regolith sintering bots would do fine).

Edited March 30, 2014 by Nuke

[vger]

Lot's of things we do today aren't sustainable long-term. That doesn't mean that economic growth itself is unsustainable, just that future growth would have to be derived from different things.

It is when you consider that no corporation is happy unless it always sees an upward slope on a graph. Making profit is never good enough. One must always profit more in one quarter than the previous one. This kind of desperation for squeezing every last buck out of something, has a way of leading to destructive practices.