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> any planetary colony has to be almost-entirely self-sufficient. Is this even remotely possible anywhere with current technology? Can we even make completely

> any planetary colony has to be almost-entirely self-sufficient. Is this even remotely possible anywhere with current technology? Can we even make completely self-sufficient colonies on Earth (like the technologically advanced kind we want to make in space, not just people living in the woods.)

lmm 12y ago
In Biosphere 2 the human volunteers ended up IIRC needing a few millilitres of liquid oxygen injected every 6 months or so. Perfect? No, and we'll probably never get to 100% perfection. But it's pretty damn close; if that was all you needed you could ship a big supply from Earth every decade or so, and it starts to look relatively affordable. (Of course most parts of space are much more hostile than an Earth desert)
- onnoonno 12y ago
  > [...] the human volunteers ended up IIRC needing a few millilitres of liquid oxygen injected [...] Citation urgently needed.
  - lmm 12y ago
    I don't have one, hence the IIRC; I'm remembering a television documentary (I think BBC's Horizon) from years ago.
- dalke 12y ago
  http://www.nytimes.com/1993/01/05/science/the-environment-oxygen-loss-causing-concern-in-biosphere-2.html http://www.nytimes.com/1993/01/05/science/the-environment-ox... says "Project leaders, expecting the decline to continue, have made arrangements to pump tons of pure oxygen into the 3.15 acres of glass domes. ... "If we decided to raise the level by 2 percent, that would be 100,000 cubic feet of gaseous oxygen,"" A short ton (907.2 kg) of oxygen is 635 cubic meters or 24160 cubic feet as a gas and 794.5 liters as a liquid ( http://www.uigi.com/o2_conv.html http://www.uigi.com/o2_conv.html ) so they would have needed 5 tons to raise the O2 levels by 2%. For what it's worth, the concrete depleted the O2 levels from 21% to 15%, so about 30 tons would have been need to fully restore the O2 levels. 800,000 mL/ton means that it was not the case that it needed "a few millilitres of liquid oxygen injected every 6 months or so." More like a few thousand liters every 6 months.
  - lmm 12y ago
    I was talking about the direct injections into the participants' lungs; I wasn't aware they'd also needed to pump oxygen into the whole thing. Thanks for the correction.
    - dalke 12y ago
      Direct injection of LOX into the lungs is dangerous. That's -180C. It will freeze lung tissue. You must have been mistaken.
- maxerickson 12y ago
  Self contained is also different than self sufficient. With a lot of carbon dioxide in the atmosphere, all you need is a good energy supply, then oxygen is easy. (A similar example, some submarines use electrolysis for oxygen)
  - userulluipeste 12y ago
    As far as I knew, the submarine air "metabolism" was chemical in nature: http://en.wikipedia.org/wiki/Chemical_oxygen_generator#Uses http://en.wikipedia.org/wiki/Chemical_oxygen_generator#Uses
    - maxerickson 12y ago
      (At least some) Nuclear subs use electrolysis: http://www.defenseindustrydaily.com/treadwell-supplies-oxygen-generator-components-for-nuclear-subs-2-04690/ http://www.defenseindustrydaily.com/treadwell-supplies-oxyge...
gambiting 12y ago
We probably could, but even in the most hostile and remote places on Earth it's easier to air-drop food and other resources than it is to grow and mine them. So there is no financial incentive to do so.
- TeMPOraL 12y ago
  Maybe we'll get a pilot colony as a part of Mars/Venus mission preparations?
jccooper 12y ago
I don't think anyone's really tried, outside the Gingery books and such. (And even Gingery bootstrapping is just a machine shop, much less modern technological civilization.) Here on Earth we have to trade long distances to get raw materials anyway, so we might a well trade other things. Even in the most isolated areas, outside goods tend to leak in. A new planetary economy would certainly have to be very tightly circumscribed in terms of materials and techniques, and even then I think it would be dismayingly huge, though modern techniques like 3D printing would help. It would be a worthwhile exercise just to plan such a thing on paper. Might make an interesting if overly-complicated game with sort of a Dwarf Fortress feel.

lmm 12y ago

In Biosphere 2 the human volunteers ended up IIRC needing a few millilitres of liquid oxygen injected every 6 months or so. Perfect? No, and we'll probably never get to 100% perfection. But it's pretty damn close; if that was all you needed you could ship a big supply from Earth every decade or so, and it starts to look relatively affordable. (Of course most parts of space are much more hostile than an Earth desert)

onnoonno 12y ago
> [...] the human volunteers ended up IIRC needing a few millilitres of liquid oxygen injected [...] Citation urgently needed.
- lmm 12y ago
  I don't have one, hence the IIRC; I'm remembering a television documentary (I think BBC's Horizon) from years ago.
dalke 12y ago
http://www.nytimes.com/1993/01/05/science/the-environment-oxygen-loss-causing-concern-in-biosphere-2.html http://www.nytimes.com/1993/01/05/science/the-environment-ox... says "Project leaders, expecting the decline to continue, have made arrangements to pump tons of pure oxygen into the 3.15 acres of glass domes. ... "If we decided to raise the level by 2 percent, that would be 100,000 cubic feet of gaseous oxygen,"" A short ton (907.2 kg) of oxygen is 635 cubic meters or 24160 cubic feet as a gas and 794.5 liters as a liquid ( http://www.uigi.com/o2_conv.html http://www.uigi.com/o2_conv.html ) so they would have needed 5 tons to raise the O2 levels by 2%. For what it's worth, the concrete depleted the O2 levels from 21% to 15%, so about 30 tons would have been need to fully restore the O2 levels. 800,000 mL/ton means that it was not the case that it needed "a few millilitres of liquid oxygen injected every 6 months or so." More like a few thousand liters every 6 months.
- lmm 12y ago
  I was talking about the direct injections into the participants' lungs; I wasn't aware they'd also needed to pump oxygen into the whole thing. Thanks for the correction.
  - dalke 12y ago
    Direct injection of LOX into the lungs is dangerous. That's -180C. It will freeze lung tissue. You must have been mistaken.
maxerickson 12y ago
Self contained is also different than self sufficient. With a lot of carbon dioxide in the atmosphere, all you need is a good energy supply, then oxygen is easy. (A similar example, some submarines use electrolysis for oxygen)
- userulluipeste 12y ago
  As far as I knew, the submarine air "metabolism" was chemical in nature: http://en.wikipedia.org/wiki/Chemical_oxygen_generator#Uses http://en.wikipedia.org/wiki/Chemical_oxygen_generator#Uses
  - maxerickson 12y ago
    (At least some) Nuclear subs use electrolysis: http://www.defenseindustrydaily.com/treadwell-supplies-oxygen-generator-components-for-nuclear-subs-2-04690/ http://www.defenseindustrydaily.com/treadwell-supplies-oxyge...

gambiting 12y ago

We probably could, but even in the most hostile and remote places on Earth it's easier to air-drop food and other resources than it is to grow and mine them. So there is no financial incentive to do so.

TeMPOraL 12y ago
Maybe we'll get a pilot colony as a part of Mars/Venus mission preparations?

jccooper 12y ago

I don't think anyone's really tried, outside the Gingery books and such. (And even Gingery bootstrapping is just a machine shop, much less modern technological civilization.) Here on Earth we have to trade long distances to get raw materials anyway, so we might a well trade other things. Even in the most isolated areas, outside goods tend to leak in. A new planetary economy would certainly have to be very tightly circumscribed in terms of materials and techniques, and even then I think it would be dismayingly huge, though modern techniques like 3D printing would help. It would be a worthwhile exercise just to plan such a thing on paper. Might make an interesting if overly-complicated game with sort of a Dwarf Fortress feel.