4 ms·

I agree with you on the issues regarding the orbital mechanics of getting to the asteroid and getting the goods back to Earth, but I think you've missed one imp

by donw 15y ago

I agree with you on the issues regarding the orbital mechanics of getting to the asteroid and getting the goods back to Earth, but I think you've missed one important idea regarding how these materials could be used. Assume $1k/kg for LEO insertion. That means a metric ton of iron, in space, would cost a million dollars if you had to ship it from Earth. Let's now say that you wanted to build a large space-based manufacturing facility, focused on producing high-value goods like zero-gravity metals and pharmaceuticals. Shipping the raw materials from Earth to build the facility would cost around a half-billion dollars, and then afterwards, you'd need to ship them the additional materials from which to produce the goods. Or, you can do something crazily ambitious -- figure out how to get the materials from somewhere in near-earth-orbit, and use that to bootstrap both interplanetary travel and space-based industry. It's crazy. I know. It's crazy enough that it just might work. Personally, I'm excited. This kind of ambition is what we need as a species right now, and I'd rather see the money spent on this than on yet another collection of mega-yachts.

michaelbuckbee 15y ago
Honestly asking here, are zero-gravity metals and pharmaceuticals 'real'? As in things that can't be made much cheaper (or at all on Earth) and that companies would jump to create if there was a platform for them?
- daeken 15y ago
  So, I don't know about zero-gravity metals and pharma, but space-based mining and manufacturing is absolutely essential for producing large-scale stations, spacecraft, and other things. It costs a ton to put things into space and during that time they're subjected to a considerable amount of force. By building in space, you don't have to build for gravity (look ma, no support structures!) and don't have to concern yourself with the cost of launches. Imagine building a massive spacecraft for long distance travel. It'd never land on a planet, just go between them; you'd take a shuttle from your planet up to the craft and leave from there. This is possible with space-based manufacturing.
  - brazzy 15y ago
    Putting millions of tonnes of material into orbit is an absolutely trivial problem compared to actually making that massive spacecraft travel anywhere meaningful.
    - wtracy 15y ago
      Well, once you're already in space, you can use nuclear pulse propulsion without leaving a giant radioactive crater on the earth's surface: http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion
  - mattmanser 15y ago
    You're missing his point entirely. If there's no real market for zero-gravity metals and pharmaceuticals, the whole venture will fail fast because it can't make money. If all you can do is build more space stuff but the stuff is more expensive than earth stuff then it's not going to work.
    - DanBC 15y ago
      Platinum is about $1500 usd per troy ounce. There are 32 troy ounces in a kg. People are estimating £1000 per kg to get stuff into LEO. It costs less to get stuff back to Earth. Surely they only have to beat $50,000 per kg to get the mining equipment up there and get the stuff back and they're in profit. And they amortise the cost of getting the mining equipment up there over all the kg they mine and return. Since they're talking about 16000000000 kg of asteroid that's a lot of amortising. And even if it doesn't have direct commercial value it has many other benefits - it is inspiring. Perhaps some children are seeing this and wanting to get into science. That's great. But maybe I'm wrong, and I really welcome better information.
      - Retric 15y ago
        That only holds up until you start shipping a lot of Platinum down at which point the market crashes. Also, it's £620 or 1,000$ to LEO right now and 100$ /lb to LEO is possible if we scale things up far enough. What NASA found out from the shuttle program is we just don't need that much stuff in space, because once stuff is up there it can stay there for a long time.
- AutoCorrect 15y ago
  reduced and zero-gravity environments allow crystals to grow faster, and in more perfect configuration than gravity-bound locations. This could lead to some really interesting metal alloys.
brazzy 15y ago
Um... why is moving the stuff from Earth to orbit so expensive? Because it takes an absurd amount of energy. What does it take to move stuff from the asteroid belt to near-Earth orbit? An even more absurd amount of energy. Absent of some breakthrough in technology that would make orbital factories seem child's play, it's not crazily ambitious, just unrealistic.
- drostie 15y ago
  Well, let's be cautious. The constraint of moving from the asteroid belt to near-Earth orbit is less "absurd amounts of energy" and more, "how fast do you want to get there?". More importantly, we're not necessarily going to choose the asteroid belt for our source, due to these time constraints. Measuring in terms of Earth's orbital radius ("astronomic units" or AU), the Moon is 2.5 mAU away, Mars and the asteroids are 1000+ mAU away, and the metallic asteroid (6178) 1986 DA approaches Earth's orbit within 161 mAU, which is to say nothing of Earth-crossing asteroids. It's true that moving an asteroid would require a lot of energy simply because they're unbelievably massive; the space shuttle propulsion system might dish out something like 10^14 joules, but a typical mining asteroid is 10^13 kg or so. But apart from that, space is frictionless, and so moving a longer distance does not require much more energy, just much more time. Sending ships to and from asteroids shouldn't require an energy cost except to cut down the travel times, in principle.
  - rphlx 15y ago
    Space does not have air friction, but it still has gravity, which you still need a large amount of energy to counter, if you want to move a massive object to a specific spot.
- abecedarius 15y ago
  Low Earth orbit is proverbially "halfway to anywhere". That is, it's not an even more absurd amount of energy to get from elsewhere in space to LEO. (Also the idea is to mine asteroids with nearer orbits, not out in the belt.) Which isn't to say I expect large-scale returns anytime soon.

by donw 15y ago

michaelbuckbee 15y ago

Honestly asking here, are zero-gravity metals and pharmaceuticals 'real'? As in things that can't be made much cheaper (or at all on Earth) and that companies would jump to create if there was a platform for them?

daeken 15y ago
So, I don't know about zero-gravity metals and pharma, but space-based mining and manufacturing is absolutely essential for producing large-scale stations, spacecraft, and other things. It costs a ton to put things into space and during that time they're subjected to a considerable amount of force. By building in space, you don't have to build for gravity (look ma, no support structures!) and don't have to concern yourself with the cost of launches. Imagine building a massive spacecraft for long distance travel. It'd never land on a planet, just go between them; you'd take a shuttle from your planet up to the craft and leave from there. This is possible with space-based manufacturing.
- brazzy 15y ago
  Putting millions of tonnes of material into orbit is an absolutely trivial problem compared to actually making that massive spacecraft travel anywhere meaningful.
  - wtracy 15y ago
    Well, once you're already in space, you can use nuclear pulse propulsion without leaving a giant radioactive crater on the earth's surface: http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion
- mattmanser 15y ago
  You're missing his point entirely. If there's no real market for zero-gravity metals and pharmaceuticals, the whole venture will fail fast because it can't make money. If all you can do is build more space stuff but the stuff is more expensive than earth stuff then it's not going to work.
  - DanBC 15y ago
    Platinum is about $1500 usd per troy ounce. There are 32 troy ounces in a kg. People are estimating £1000 per kg to get stuff into LEO. It costs less to get stuff back to Earth. Surely they only have to beat $50,000 per kg to get the mining equipment up there and get the stuff back and they're in profit. And they amortise the cost of getting the mining equipment up there over all the kg they mine and return. Since they're talking about 16000000000 kg of asteroid that's a lot of amortising. And even if it doesn't have direct commercial value it has many other benefits - it is inspiring. Perhaps some children are seeing this and wanting to get into science. That's great. But maybe I'm wrong, and I really welcome better information.
    - Retric 15y ago
      That only holds up until you start shipping a lot of Platinum down at which point the market crashes. Also, it's £620 or 1,000$ to LEO right now and 100$ /lb to LEO is possible if we scale things up far enough. What NASA found out from the shuttle program is we just don't need that much stuff in space, because once stuff is up there it can stay there for a long time.
AutoCorrect 15y ago
reduced and zero-gravity environments allow crystals to grow faster, and in more perfect configuration than gravity-bound locations. This could lead to some really interesting metal alloys.

brazzy 15y ago

Um... why is moving the stuff from Earth to orbit so expensive? Because it takes an absurd amount of energy. What does it take to move stuff from the asteroid belt to near-Earth orbit? An even more absurd amount of energy. Absent of some breakthrough in technology that would make orbital factories seem child's play, it's not crazily ambitious, just unrealistic.

drostie 15y ago
Well, let's be cautious. The constraint of moving from the asteroid belt to near-Earth orbit is less "absurd amounts of energy" and more, "how fast do you want to get there?". More importantly, we're not necessarily going to choose the asteroid belt for our source, due to these time constraints. Measuring in terms of Earth's orbital radius ("astronomic units" or AU), the Moon is 2.5 mAU away, Mars and the asteroids are 1000+ mAU away, and the metallic asteroid (6178) 1986 DA approaches Earth's orbit within 161 mAU, which is to say nothing of Earth-crossing asteroids. It's true that moving an asteroid would require a lot of energy simply because they're unbelievably massive; the space shuttle propulsion system might dish out something like 10^14 joules, but a typical mining asteroid is 10^13 kg or so. But apart from that, space is frictionless, and so moving a longer distance does not require much more energy, just much more time. Sending ships to and from asteroids shouldn't require an energy cost except to cut down the travel times, in principle.
- rphlx 15y ago
  Space does not have air friction, but it still has gravity, which you still need a large amount of energy to counter, if you want to move a massive object to a specific spot.
abecedarius 15y ago
Low Earth orbit is proverbially "halfway to anywhere". That is, it's not an even more absurd amount of energy to get from elsewhere in space to LEO. (Also the idea is to mine asteroids with nearer orbits, not out in the belt.) Which isn't to say I expect large-scale returns anytime soon.