4 ms·

Indeed, the start of extra-terrestrial mining ( the exploration part - no exploitation ATM ). Altough this is mining on a planet ( with gravity and atmosphere

by ccozan 14y ago

Indeed, the start of extra-terrestrial mining ( the exploration part - no exploitation ATM ). Altough this is mining on a planet ( with gravity and atmosphere) , I am keen on asteroid mining, physics could be quite different there. Even the Moon could be quite difficult to mine ( due to the dust ).

JoeAltmaier 14y ago
Indeed, different. No gravity or wind to blow away dust - it will just hang there, for 10,000 years, a growing problem as mining activities continue. Gripping a rock to drill becomes a major problem - no weight to press the drill into the surface. Then, when a chuck of material is gotten loose, it will just drift away - how to tether it, guide it into a smelter? How does the smelter keep the material contained, how does it separate metal from slag in zero gravity? There are half a dozen major engineering hurdles before asteroid mining can be attempted. Add to that transportation and energy hurdles - also unprecedented in mining history. Finally, control delay of minutes make remote operation impossible - will have to be completely automated. Right now asteroid mining is a pipe dream. It would be far easier to do deep-core mining right here on Earth for instance - none of those issue apply. I don't say it would be easy - just easier than asteroid mining.
- muyuu 14y ago
  Wouldn't the dust just slowly deposit itself? 10,000 years sounds a bit much. The moon does have some gravitational pull, and there being no air resistance or viscosity, my guess would be much shorter than 10,000 years... maybe just hours or days. (Talking about the moon, not small asteroids - for these I guess dust can even escape them).
  - JoeAltmaier 14y ago
    Asteroids have negligible gravity. Solar wind is miniscule so far from the Sun (twice as far as the Earth, 1/10 the radiant effects). Mining generates prodigious amounts of dust. It would grow linearly until you were operating essentially in a dense field of dust. It would stay - maybe not 10,000 years, but forever for mining purposes.
    - willismichael 14y ago
      My first reaction to this conversation was to imagine some kind of vacuum hose attachment. My second thought was "oh yeah... that won't work at all" :)
      - S4M 14y ago
        I had the same reaction - actually, I was thinking in some sort of spatial hoover - but I am still trying to work out in my mind if it would work. Can you explain how you came to the conclusion it wouldn't?
        pranjalv123 14y ago
        There's no air.
        willismichael 14y ago
        Exactly, I almost facepalmed when I realized the absurdity of a vacuum hose... although I do wonder if something along the lines of a CO2 compression canister would work to blow away dust. I'm assuming that it would be prohibitively expensive to have to constantly ship compressed gas to the mining site though.
        pavel_lishin 14y ago
        That's why you'd just ship an asteroid that's already made of gas and liquid, and mine that for your gas. "Evaporate some more nitrogen off that asteroid, Joe, we need to blow this dust away."
        B-Con 14y ago
        And to be specific, vaccums work by creating a low pressure locality inside of a gas. Same principle behind a backwards fan. Push the gas one way, you create a small low pressure point that other gas then fills. In a vaccume-cleaner the region of gas that can rush in to fill the low pressure point is at the end of a nozzle. Really, you're not vacuuming up objects, they're just along for the ride in their immediate atmosphere. (...And in space, you have no atmosphere to manipulate.)
- lutusp 14y ago
  > No gravity or wind to blow away dust - it will just hang there, for 10,000 years, a growing problem as mining activities continue. Not without an atmosphere. Even a small asteroid has enough gravity to cause dust to settle to the surface rather quickly -- or move away if the dust particles have escape velocity or greater. > Then, when a chuck of material is gotten loose, it will just drift away ... Yes, if the object is given an initial velocity greater than escape velocity. Otherwise it will return to the surface, but it won't just drift about.
- abdullahkhalids 14y ago
  Earth density ~ 1g/cm^3 = 1000kg/m^3 ~ Asteriod density Asteroid Radius = 1km. Asteroid mass = 4/3piR^3density = 4.2x10^12kg acceleration = G M/R^2 = 280 micrometers/second if initial velocity is zero, a dust particle will settle in about 300 seconds from a height of 10m at this acceleration. They can always escape if initial speed is high, but if not, they will settle down pretty fast. Use science!
  - Scaevolus 14y ago
    Earth's density is 5.5g/cm^3. Asteroid densities vary, averaging maybe 2.5g/cm^3. Metallic asteroids are about 5g/cm^3.
- JoeAltmaier 14y ago
  Lovely responses, I'm gratified to see so much interest in this topic. Have to observe though, its pretty easy to make things work out by assuming a planetoid or large asteroid. Yet the vast majority of objects in the asteroid belt are under half a km in radius. Prospectors don't get to pick where the metals are. And by mass, or count, or chance, its overwhelmingly likely to find it in one of the small asteroids. If you assume towing an asteroid into orbit and then mining, now we know its a tiny asteroid and the dust is still a problem. However it seems foolish in the extreme to haul gigatons of slag to orbit and then mine it, instead of just hauling back the valuable stuff. The energy costs are going to make or break the feasibility of any space mining project.
  - pavel_lishin 14y ago
    If the mining isn't automated - that is, if mining requires a human presence - it hauling the gigatons to Earth orbit might not seem to foolish. Aside from the cost of having to ship people, equipment, air, water and food to the asteroid belt, an accident in Earth orbit is much easier to deal with than one past Mars orbit. "Don't worry, Miner Mike - a Space Ambulance is on its way! Just hang in there for four or five more months."

by ccozan 14y ago

JoeAltmaier 14y ago

Indeed, different. No gravity or wind to blow away dust - it will just hang there, for 10,000 years, a growing problem as mining activities continue. Gripping a rock to drill becomes a major problem - no weight to press the drill into the surface. Then, when a chuck of material is gotten loose, it will just drift away - how to tether it, guide it into a smelter? How does the smelter keep the material contained, how does it separate metal from slag in zero gravity? There are half a dozen major engineering hurdles before asteroid mining can be attempted. Add to that transportation and energy hurdles - also unprecedented in mining history. Finally, control delay of minutes make remote operation impossible - will have to be completely automated. Right now asteroid mining is a pipe dream. It would be far easier to do deep-core mining right here on Earth for instance - none of those issue apply. I don't say it would be easy - just easier than asteroid mining.

muyuu 14y ago
Wouldn't the dust just slowly deposit itself? 10,000 years sounds a bit much. The moon does have some gravitational pull, and there being no air resistance or viscosity, my guess would be much shorter than 10,000 years... maybe just hours or days. (Talking about the moon, not small asteroids - for these I guess dust can even escape them).
- JoeAltmaier 14y ago
  Asteroids have negligible gravity. Solar wind is miniscule so far from the Sun (twice as far as the Earth, 1/10 the radiant effects). Mining generates prodigious amounts of dust. It would grow linearly until you were operating essentially in a dense field of dust. It would stay - maybe not 10,000 years, but forever for mining purposes.
  - willismichael 14y ago
    My first reaction to this conversation was to imagine some kind of vacuum hose attachment. My second thought was "oh yeah... that won't work at all" :)
    - S4M 14y ago
      I had the same reaction - actually, I was thinking in some sort of spatial hoover - but I am still trying to work out in my mind if it would work. Can you explain how you came to the conclusion it wouldn't?
      - pranjalv123 14y ago
        There's no air.
        willismichael 14y ago
        Exactly, I almost facepalmed when I realized the absurdity of a vacuum hose... although I do wonder if something along the lines of a CO2 compression canister would work to blow away dust. I'm assuming that it would be prohibitively expensive to have to constantly ship compressed gas to the mining site though.
        pavel_lishin 14y ago
        That's why you'd just ship an asteroid that's already made of gas and liquid, and mine that for your gas. "Evaporate some more nitrogen off that asteroid, Joe, we need to blow this dust away."
        B-Con 14y ago
        And to be specific, vaccums work by creating a low pressure locality inside of a gas. Same principle behind a backwards fan. Push the gas one way, you create a small low pressure point that other gas then fills. In a vaccume-cleaner the region of gas that can rush in to fill the low pressure point is at the end of a nozzle. Really, you're not vacuuming up objects, they're just along for the ride in their immediate atmosphere. (...And in space, you have no atmosphere to manipulate.)
lutusp 14y ago
> No gravity or wind to blow away dust - it will just hang there, for 10,000 years, a growing problem as mining activities continue. Not without an atmosphere. Even a small asteroid has enough gravity to cause dust to settle to the surface rather quickly -- or move away if the dust particles have escape velocity or greater. > Then, when a chuck of material is gotten loose, it will just drift away ... Yes, if the object is given an initial velocity greater than escape velocity. Otherwise it will return to the surface, but it won't just drift about.
abdullahkhalids 14y ago
Earth density ~ 1g/cm^3 = 1000kg/m^3 ~ Asteriod density Asteroid Radius = 1km. Asteroid mass = 4/3piR^3density = 4.2x10^12kg acceleration = G M/R^2 = 280 micrometers/second if initial velocity is zero, a dust particle will settle in about 300 seconds from a height of 10m at this acceleration. They can always escape if initial speed is high, but if not, they will settle down pretty fast. Use science!
- Scaevolus 14y ago
  Earth's density is 5.5g/cm^3. Asteroid densities vary, averaging maybe 2.5g/cm^3. Metallic asteroids are about 5g/cm^3.
JoeAltmaier 14y ago
Lovely responses, I'm gratified to see so much interest in this topic. Have to observe though, its pretty easy to make things work out by assuming a planetoid or large asteroid. Yet the vast majority of objects in the asteroid belt are under half a km in radius. Prospectors don't get to pick where the metals are. And by mass, or count, or chance, its overwhelmingly likely to find it in one of the small asteroids. If you assume towing an asteroid into orbit and then mining, now we know its a tiny asteroid and the dust is still a problem. However it seems foolish in the extreme to haul gigatons of slag to orbit and then mine it, instead of just hauling back the valuable stuff. The energy costs are going to make or break the feasibility of any space mining project.
- pavel_lishin 14y ago
  If the mining isn't automated - that is, if mining requires a human presence - it hauling the gigatons to Earth orbit might not seem to foolish. Aside from the cost of having to ship people, equipment, air, water and food to the asteroid belt, an accident in Earth orbit is much easier to deal with than one past Mars orbit. "Don't worry, Miner Mike - a Space Ambulance is on its way! Just hang in there for four or five more months."