Mining Asteroids. How Would you do it?

Discussion in 'Architecture & Engineering' started by ISDAMan, Apr 30, 2015.

  1. ISDAMan Thank You Jesus! Registered Senior Member

    Messages:
    378
    It is well known that asteroids are a potential treasure trove of valuable products such as gold, nickle, iridium, and iron. Some have theorized that it may be possible to capture an asteroid and put it into orbit around our moon for easy access. How wise do you think that would be to do and, how would you overcome the challenges of attempting to dig into extremely hard substances while in extremely low gravity?

    For my answer:

    I wouldn't want to put anything in orbit around our moon. Human error will occur. The question is only, to what extent would the damage be? Such a venture would produce inordinate risk to most with all the wealth being filtered to a few. Even if everyone shared the money (which would essentially devalue the money making the venture economically useless), it's not worth the risk of a potential unforeseen chain of events disturbing our moon's orbit or, something even worse.

    I would choose to put asteroids in orbit around Jupiter. That system can accept far more fluctuation and, there's not a planet full of humans to be placed at risk there. Jupiter's gravity would assist in mining asteroids if we drill into the side of the asteroid facing the planet. Still, that would not be enough.

    We would actually need to create our own moon first. This really wouldn't be all that hard though. It's more time an resource consuming than anything. We'd start with two smaller asteroids. We'd place them in orbit around Jupiter in a perforated bag. The bag would then be filled with a foaming product able to cement the two asteroids together. The cement would need to be strong but, something we could drill into in low gravity. We'd repeat the basic joining process a few times until we had enough sets to fill the biggest bag we could ever produce. We'd fill the biggest bag with the sets and cement them all together. The perforations, having allowed cement to harden beyond the boundary of the bags, would allow for the second stage cementing to bond the sets together more securely. This would still not be enough though.

    From there, small asteroids could be lowered to make aggregate contact with our artificial moon's surface. They would then be covered in a perforated tarp and cemented in place. This third stage cementing is how we would get our artificial moon's mass to whatever we wanted. Throughout the entire process of construction, we would need to control the rotation and orbital behavior of our moon. Once constructed and subsequent to any settling, the artificial moon would be covered with a special ballistic treatment designed to reduce the transfer of energy in the event of any surface impact. Since much of the earlier stage cement would remain only nominally compressed, it would also assist in dissipating the energy of impacts. A track could be placed around the moon allowing us to orient the main facility so as to keep it located between our surface and Jupiter. In that way, we could make the most out of the gravity of our artificial moon and the gravity of Jupiter pulling against it as well as reduce the possibility of damage to our facility due to impact. The main facility is where we would bring other asteroids to be broken up and processed. We could always add more tracks to do work at other facilities and to bring the lowered asteroids to the main facility. With the radiation in that area being just a touch unfriendly, shielding technology would need to be advanced and adjustable. Most of all the facilities would need to be automated.
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. youreyes amorphous ocean Valued Senior Member

    Messages:
    2,826
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. paddoboy Valued Senior Member

    Messages:
    21,448
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. ISDAMan Thank You Jesus! Registered Senior Member

    Messages:
    378
    I considered further the great expense and danger of my previous idea and came up with an on site harvesting idea. I guess, in reality, it would still be resource intensive but, it would save time and have a lower radiation risk.

    A smaller asteroid would be captured and bagged so as to control its motions. From there, it would be loaded and tethered within the center of a larger container. That container would be filled with a suitably dense concrete. Once hardened, the new form would be cylindrical and have specially shaped ends to allow a machine to grapple it. The product would be loaded into a mill, spun up to high speed and, divided in two by a set of scissor-like diamond tipped retching hydraulic chainsaws. The chainsaws would go around their tracks at high speed when wanted and at very slow speed when wanted. This would allow for diamond bits to be easily replaced while maximizing cutting speed and not bringing the cut to a halt since the cylinder would still be rotating. Once divided, the two halves could be reformed and redivided again and again until they could fit into cargo vessels and flown back to Earth for processing. Divisions would only be by halves because only the ends of cylinders could be grappled.

    The nice thing about this system is that, once you've collected enough resources, you'll be able to more quickly bring other mills online. The size of your mills could grow from there.
     
  8. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    There is nothing that exists on any asteroid that can not be gotten or made here on Earth for less than one percent of the cost of going to the asteroid, extracting it, and returning just what you want to Earth.

    If you disagree what is it? and what is a realistic cost per kg of it returned to Earth?
     
  9. ISDAMan Thank You Jesus! Registered Senior Member

    Messages:
    378
    I think you're likely correct with that until the demand goes through the roof and the applications for our resources shift to off world. If we want to build a long term manned observatory outside of the heliopolis as a crazy example, we'd want ridiculously thick shielding and absurd quantities of reserve raw materials on site so as to perform repairs and allow for new construction. Mining asteroids and not allowing any of the material to feed the open market would mean that there would be no market collapses associated with the project.

    There could be less likely Earth based applications I suppose. If on some outside chance we detected a vast meteoroid field out in deep space that would eventually rain meteors down on the Earth for a period of several decades, we might become hungry for iridium. We could build a vast network of domes and subterranean structures.

    Anyone still chilling out on this planet when our sun starts to expand might want to make finding a way to shift the planet's orbit a priority. Iridium might come to the rescue again. If we build up a huge stockpile and stash it all over the planet, once we have enough, we can quickly bring it all together into one place making a super mountain of mass. Once we've got a nice warble, we spread it back out just as quickly as we made it flinging us off into a wider orbit. This, of course, would be the ultimate action movie scene of outrunning a fireball.
     
  10. paddoboy Valued Senior Member

    Messages:
    21,448

    Asteroids in the future will be mined. They will probably be in either lunar or Earth orbit, and would not in anyway perturb the orbit of either.


    The company I have linked to are planning to mine and recover/re-orbit Asteroids, and they are not full of Idiots.
     
  11. paddoboy Valued Senior Member

    Messages:
    21,448

    Yep, all true, still one day it will be undertaken.
    What is mined from asteroids would probably in the first instant be used for a future potential lunar base, so it may not need to be returned to Earth.
    http://www.planetaryresources.com/#home-company
     
  12. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    Not much different. Any lunar base will get most of its needs from the moon. Electrical energy via the sun but with conversion efficiency at least 3 times greater than single layer solar cells can achieve. - Using a thermal engine with high Carnot limit due to extreme cold of dark side surface with both heat and cold, stored 14 days a few meters deep in the ground. (Parallel but separated thermal strips with aluminized foil insulation cover that slides from the hot storage strip to the cold one at sunrise and then reverses 14 days later as the sun sets keeping the thermal engine's hot source at nearly 500K)*

    With much less gravity for mining equipment to work against, and electric power that is less than half the cost on it is on earth, the argument I made about cheaper to get locally any thing needed, is even more valid on the moon. Remember the moon is a piece of earth's crust, blasted off earth into orbit, millions of years ago. What is in the Earth's crust is on the moon too - just easier and cheaper to take; however, H2O is rare and in hydrated crystals, mainly.

    Thus, it is not clear which is cheaper - transport water from earth or make it there. In any case it must be nearly 100% recycled and there is NONE to be had from an asteroid of the metallic type or any reason to think the "stony ones" hold even as much per ton as the moon does.

    * If the cold source "looks" for 14 days at <10K black sky, then the thermal engine's cold sink might be 100 K or so at local sun rise. The hot storage strip is at its peak temperature at local sun set. When hot is hottest and cold is coldest, the Carnot limit on conversion efficiency is about: (500 -100)/ 500 = 80% but 14 days later may be only (400- 200)/400 = 50% , but no real engine gets the Carnot limit, so the average conversion efficiency may be "only" 60%. AFAIK, no single layer solar cell can get 1/4 of that and of course they cost much more than some buried tubes for the "working fluid" and a sliding aluminized insulation cover.

    To protect from the occasional lethal solar storms, that last for a few earth days, the moon base will be mostly a few meters below the moon's surface too. I. e. excavation robots will need to do a lot of digging before the first human inhabitants arrive.
     
    Last edited by a moderator: May 1, 2015
  13. GeoffP Caput gerat lupinum Valued Senior Member

    Messages:
    22,087
    Well, I'd send space-dwarves, obviously.

    Please Register or Log in to view the hidden image!

     
  14. cosmictraveler Be kind to yourself always. Valued Senior Member

    Messages:
    33,264
    Just think about the cost to do any mining. It would cost so much to do it that it wouldn't be prudent to even think about it. A pound of anything on Earth would cost a thousand times less than mining on a asteroid.
     
  15. paddoboy Valued Senior Member

    Messages:
    21,448

    Don't tell me, tell the Planetary Resources people.
    Let me again make myself clear. Without putting any time frame on it, and assuming humanity can survive, we will eventually mine Asteroids instead of Earth, we will have a Lunar base, we will walk on Mars and have a base there too, and we will undertake inter stellar travel.
     
  16. billvon Valued Senior Member

    Messages:
    12,755
    True. And a pound of anything in Great Britain circa 1700 cost much, much less than mining in the Americas and shipping it back via dangerous, expensive and unreliable sailing ships. Yet here we are, mining in the Americas. Even shipping finished goods to the UK.
     

Share This Page