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Getting large-scale mining operations in space, or any kind of industrial base for that matter, would require us to start fabricating things in space. Getting

Getting large-scale mining operations in space, or any kind of industrial base for that matter, would require us to start fabricating things in space. Getting something in orbit will always be expensive and prohibitive, even when space elevators are built, so there will be enough incentive to start building things in space.

TeMPOraL 7y ago
And then you realize that sending material upwell to support orbital fabrication is uneconomical, while suddenly mining those materials from asteroids makes double-plus sense. Orbital fabrication and mining are intertwined, but together they're the key to any long-term human presence outside Earth.
moneytide1 7y ago
I've wondered how interstellar smelting would work. There would need to be centripetal force on the foundry station to keep metals flowing. Nearby ice could provide hydrogen and oxygen for propulsion and even heat for steam turbine electricity for the plant. Certainly there would be uranium present as well so fission would be an option, albeit more complicated. Four/eight year military service spent policing/polluting the world could be replaced by short "tours" in asteroid belt operations. The key to all of this would be constant launches and flow of material/labor, ideally with international cooperation. The high frequency of launches in itself is a safety feature - stranded crews would be able to expect fly-bys. It would be expensive at first because we would essentially be ejecting many resources away from the planet. But the promise of heavy-industry eventually zoned outside of our natural atmosphere could be the [non-classical] incentive.
- JoeAltmaier 7y ago
  Rotation might be done with magnetic fields instead of ejecting ionized gas (water etc). And dirty fission power is very practical in space, where the inverse-square law can make it quite harmless.
  - moneytide1 7y ago
    Would the magnetic field be provided by an auxiliary station adjacent to the rotating foundry? Or could the structure propel it's own smelting vats somehow via the field on arms attached to a central bearing? It would seem more efficient with a field rather than constantly ejecting usable material. How is the inverse squared law applied to space fission? Ease of cooling?
    - ben_w 7y ago
      > How is the inverse squared law applied to space fission? Ease of cooling? If you double the distance, the radiation hazard reduces by a factor of four. This is why the Sun — an unshielded fusion reactor — hasn’t already killed everyone.

TeMPOraL 7y ago

And then you realize that sending material upwell to support orbital fabrication is uneconomical, while suddenly mining those materials from asteroids makes double-plus sense. Orbital fabrication and mining are intertwined, but together they're the key to any long-term human presence outside Earth.

moneytide1 7y ago

I've wondered how interstellar smelting would work. There would need to be centripetal force on the foundry station to keep metals flowing. Nearby ice could provide hydrogen and oxygen for propulsion and even heat for steam turbine electricity for the plant. Certainly there would be uranium present as well so fission would be an option, albeit more complicated. Four/eight year military service spent policing/polluting the world could be replaced by short "tours" in asteroid belt operations. The key to all of this would be constant launches and flow of material/labor, ideally with international cooperation. The high frequency of launches in itself is a safety feature - stranded crews would be able to expect fly-bys. It would be expensive at first because we would essentially be ejecting many resources away from the planet. But the promise of heavy-industry eventually zoned outside of our natural atmosphere could be the [non-classical] incentive.

JoeAltmaier 7y ago
Rotation might be done with magnetic fields instead of ejecting ionized gas (water etc). And dirty fission power is very practical in space, where the inverse-square law can make it quite harmless.
- moneytide1 7y ago
  Would the magnetic field be provided by an auxiliary station adjacent to the rotating foundry? Or could the structure propel it's own smelting vats somehow via the field on arms attached to a central bearing? It would seem more efficient with a field rather than constantly ejecting usable material. How is the inverse squared law applied to space fission? Ease of cooling?
  - ben_w 7y ago
    > How is the inverse squared law applied to space fission? Ease of cooling? If you double the distance, the radiation hazard reduces by a factor of four. This is why the Sun — an unshielded fusion reactor — hasn’t already killed everyone.