6 ms·

Pressurised natural caves could offer a home from home on the Moon

22 points by MoSattler 4y ago

MoSattler 4y ago
https://archive.ph/ZvgbT https://archive.ph/ZvgbT
Animats 4y ago
But why? The Moon will probably be colonized by robots. Robots can be built to operate in vacuum. Off earth, humans are stuck indoors except for occasional excursions in space suits.
- delecti 4y ago
  If we ever have any sort of base on the moon, even an automated one, inevitably humans will want to move there too. Might as well think about how that might work with time to plan ahead.
  - _dain_ 4y ago
    Nobody lives in Antarctica for its own sake, and that's a lot closer to home. You can breathe the air there. If we could replace McMurdo base with robots, nobody would weep.
    - anoonmoose 4y ago
      Wouldn't expect that to change until/unless we find some natural resources worth exploiting down there.
    - swagasaurus-rex 4y ago
      Plenty of people go to Antarctica for its own sake. You can buy a cruise ship ticket to Antarctica for $30,000.
- jjoonathan 4y ago
  To fix the robots. Moon dust is evil -- unweathered, sharp, and electrostatically suspended in clouds due to solar wind charging it up. Until robots get good at repair work, some poor humans are probably going to get stuck with this job. To do repacking/refueling logistics for more ambitious manned missions. To unpack and deploy infrastructure. To shoot at people who try to jack the infrastructure :)
dvh 4y ago
What is a "home from home"? I'm not familiar with this phrase.
- zamadatix 4y ago
  The British version of "home away from home" if you've ever heard it said like that. Basically a place that's not home but you can feel comfortable/familiar as if it were anyways.
  - rob74 4y ago
    "home away from home" makes sense, but if you take away the away, I personally can't make sense of it anymore - if it's "from home", you are doing it (whatever "home" may mean when used as a verb) while you're at home, like in "work from home", so... ?!
    - kmill 4y ago
      I think it's the same 'from' as 'far from home', but I'm not British so take that with a grain of salt. Even 'work from home' is weird. The only way I can read it if I really think about it is your work is coming from home.
- flangola7 4y ago
  Pretty clearly a typo
BigCryo 4y ago
I recommend the Heinlein short story entitled gentleman be seated
- anoonmoose 4y ago
  The Heinlein novel "The Moon Is A Harsh Mistress" also features pressurized living spaces on the moon heavily.
ortusdux 4y ago
I still think this was part of Elon's motivation for investing in his Boring Company. Those machines could be used to create subsurface chambers for both habitation and transportation, while generating plenty of crushed rock for surface construction.
- kulahan 4y ago
  Elon only gets into industries with medium-hanging fruit and huge payoffs. The best ground drillers in the world moved at something like 3"/hr. It's hard to go faster than that, but if you could, the payoff (building tunnels for trains, construction projects, mining, etc.) would be insane.
  - tessierashpool 4y ago
    > Elon only gets into industries with medium-hanging fruit and huge payoffs. what's the huge payoff with Tesla supposed to be? or Twitter?
    - umeshunni 4y ago
      > what's the huge payoff with Tesla supposed to be? Huh? It's few hundred billion dollar company that's the biggest EV company and by some metrics the largest car company.
      - tessierashpool 4y ago
        OK, it's true that its stock price is high enough that the market has priced it above the rest of the entire automotive industry. but that price will undoubtedly crash, and it's not the biggest car company by any realistic or stable metric. they've been slashing their prices and they make cars which catch fire. they've been around a decade and they still haven't turned a profit. and again, what's the huge payoff going to be with Twitter?
        burkaman 4y ago
neontomo 4y ago
Going full circle back to cavemen.
- throwayyy479087 4y ago
  I get this is a joke but the reason we find stuff in caves isn't that they _lived there full time_ it's that stuff was only preserved there. Try building a wood house on the shores of the ancient Mississippi and seeing if you can find a trace of it in 30,000 years.
- 1970-01-01 4y ago
  Astrocavemen will need to first create air, water, and food. Then they will be able to create fire. Now we've gone full circle.
credit_guy 4y ago
The big problem with Moon colonies is that the Moon lacks carbon and nitrogen. Hydrogen is also hard to come by. Let's say we find a lava tube that is 15 meters in diameter and 100 meters long. That is about 70 thousand cubic meters, and would require about 70 tons of nitrogen to create an artificial atmosphere similar to the one we have here (we can ignore the oxygen, or which there is plenty in the lunar regolith). Bringing 70 tons of stuff from Earth is not impossible, but far from easy, even given Musk's Starship. It is much more likely that initially we'll build something similar in volume to the International Space Station, where we were able to keep a breathable atmosphere for 20+ years. Which, by the way, has a volume of only about 1000 cubic meters (out of which only about 400 m3 habitable).
- patall 4y ago
  My impression was that it's mostly about particle pressure and 100% O_2 at 0.2 atmospheres would also be possible. ISS keeps with the normal atmospheric pressure and 80% nitrogen but from what one reads on the internet, that is more for compatibility reasons and not because we humans cannot sustain a pure oxygen, low pressure environment, once you go all in (and stay there for prolonged times).
  - credit_guy 4y ago
    A 100% O2 atmosphere would produce oxygen toxicity in the human body. Plus, it would create a huge fire hazard. Now, it's possible that we could be ok with a gas mix that's different from the traditional 21% oxygen 78% nitrogen we have here. But we don't like to experiment on humans. A different gax mix would need a lot of long term testing on animals before we'd ever consider using it.
    - dahdum 4y ago
      I believe you may be incorrect, the fraction is not the problem [1]. Apollo also ran with pure O2, even after an early accident under higher pressure [2]. > In such applications as extra-vehicular activity, high-fraction oxygen is non-toxic, even at breathing mixture fractions approaching 100%, because the oxygen partial pressure is not allowed to chronically exceed 0.3 bar (4.4 psi). 1. https://en.m.wikipedia.org/wiki/Oxygen_toxicity https://en.m.wikipedia.org/wiki/Oxygen_toxicity 2. https://www.popsci.com/why-did-nasa-still-use-pure-oxygen-after-apollo-1-fire/ https://www.popsci.com/why-did-nasa-still-use-pure-oxygen-af...
driggs 4y ago
This idea is unlikely to work unless the entirety of the pressurized volume is encased in a giant "balloon" or some sort of sealant coating the entirety of the cave's surface. Lava tubes are formed from flowing molten basalt, and basalt shrinks when it cools, forming contraction cracks. If we're producing breathable atmosphere and pumping it into lava tubes, it's destined to leak from innumerable cracks in the cave walls. And it'd presumably leak out faster than we can produce new breathable atmosphere. This differs from proposed deep "carbon capture" strategies, where we'd pump large amounts of CO2 underground for storage; in that case, the depth provides an airtight seal due to significant overburden, impermeable clays/shales, and perched aquifers above it. But lava tubes, by their very nature, are always very near the surface. That's because lava tubes - unlike other types of caves - form on the surface as molten basalt flows over it. They generally don't survive for long (geologically speaking) nor survive significant sedimentation which would bury them deeply. Lava tube caves can certainly provide shelter, and can significantly buffer temperature changes. But it would be extremely difficult to use them as an airtight biosphere. Source: I'm former cave resource manager for the National Park Service at an NPS unit with 700+ lava tube caves which was used by NASA for training and ongoing research.
- more_corn 4y ago
  Yeah, that’s likely the idea. The rock is more to protect from radiation, cosmic rays and punctures than to capture the atmosphere. I’d probably build it in multiple layers too. Low pressure on the outside and mounting pressure in internal domes.
falsaberN1 4y ago
Isn't lunar dust an absolute nightmare made of sharp shards of material melted/compressed from large object impacts, or something of the sort? That has to be a nightmare on the skin or soft body tissues. And devices. The idea is fun, but I'm definitely not moving there. I mean uuuuh "it is my duty to let the younger generations populate the new frontiers while I hold the fort in their absence". Yeah, let's roll with that. Knowing my luck I'd be the first Selenite to die from lung lacerations infected from recycled air because the single live native bacterium of the moon decided to get cozy in my air filter, just the day the neighbor decided to clean the rugs. Or I'd get the only non-functioning internet connection in the planet. "Satellite's fried, kid, can't do nothin' until next rocket comes with da spare!". Jokes aside, is there some sort of good reference about the internals of the Moon? I never gave it a lot of thought but it makes sense it'd have some internal structure. While I don't think there's a lot of lunar spelunkers on the job, maybe we got something with scanning or something. I don't even know where to look.
- more_corn 4y ago
  Correct. Moon dust is also terrible for rubber seals and other things used to create airtight environments.

22 points by MoSattler 4y ago

https://archive.ph/ZvgbT https://archive.ph/ZvgbT

But why? The Moon will probably be colonized by robots. Robots can be built to operate in vacuum. Off earth, humans are stuck indoors except for occasional excursions in space suits.

delecti 4y ago
If we ever have any sort of base on the moon, even an automated one, inevitably humans will want to move there too. Might as well think about how that might work with time to plan ahead.
- _dain_ 4y ago
  Nobody lives in Antarctica for its own sake, and that's a lot closer to home. You can breathe the air there. If we could replace McMurdo base with robots, nobody would weep.
  - anoonmoose 4y ago
    Wouldn't expect that to change until/unless we find some natural resources worth exploiting down there.
  - swagasaurus-rex 4y ago
    Plenty of people go to Antarctica for its own sake. You can buy a cruise ship ticket to Antarctica for $30,000.
jjoonathan 4y ago
To fix the robots. Moon dust is evil -- unweathered, sharp, and electrostatically suspended in clouds due to solar wind charging it up. Until robots get good at repair work, some poor humans are probably going to get stuck with this job. To do repacking/refueling logistics for more ambitious manned missions. To unpack and deploy infrastructure. To shoot at people who try to jack the infrastructure :)

dvh 4y ago

What is a "home from home"? I'm not familiar with this phrase.

zamadatix 4y ago
The British version of "home away from home" if you've ever heard it said like that. Basically a place that's not home but you can feel comfortable/familiar as if it were anyways.
- rob74 4y ago
  "home away from home" makes sense, but if you take away the away, I personally can't make sense of it anymore - if it's "from home", you are doing it (whatever "home" may mean when used as a verb) while you're at home, like in "work from home", so... ?!
  - kmill 4y ago
    I think it's the same 'from' as 'far from home', but I'm not British so take that with a grain of salt. Even 'work from home' is weird. The only way I can read it if I really think about it is your work is coming from home.
flangola7 4y ago
Pretty clearly a typo

BigCryo 4y ago

I recommend the Heinlein short story entitled gentleman be seated

anoonmoose 4y ago
The Heinlein novel "The Moon Is A Harsh Mistress" also features pressurized living spaces on the moon heavily.

ortusdux 4y ago

I still think this was part of Elon's motivation for investing in his Boring Company. Those machines could be used to create subsurface chambers for both habitation and transportation, while generating plenty of crushed rock for surface construction.

kulahan 4y ago
Elon only gets into industries with medium-hanging fruit and huge payoffs. The best ground drillers in the world moved at something like 3"/hr. It's hard to go faster than that, but if you could, the payoff (building tunnels for trains, construction projects, mining, etc.) would be insane.
- tessierashpool 4y ago
  > Elon only gets into industries with medium-hanging fruit and huge payoffs. what's the huge payoff with Tesla supposed to be? or Twitter?
  - umeshunni 4y ago
    > what's the huge payoff with Tesla supposed to be? Huh? It's few hundred billion dollar company that's the biggest EV company and by some metrics the largest car company.
    - tessierashpool 4y ago
      OK, it's true that its stock price is high enough that the market has priced it above the rest of the entire automotive industry. but that price will undoubtedly crash, and it's not the biggest car company by any realistic or stable metric. they've been slashing their prices and they make cars which catch fire. they've been around a decade and they still haven't turned a profit. and again, what's the huge payoff going to be with Twitter?
      - burkaman 4y ago

neontomo 4y ago

Going full circle back to cavemen.

throwayyy479087 4y ago
I get this is a joke but the reason we find stuff in caves isn't that they _lived there full time_ it's that stuff was only preserved there. Try building a wood house on the shores of the ancient Mississippi and seeing if you can find a trace of it in 30,000 years.
1970-01-01 4y ago
Astrocavemen will need to first create air, water, and food. Then they will be able to create fire. Now we've gone full circle.

credit_guy 4y ago

The big problem with Moon colonies is that the Moon lacks carbon and nitrogen. Hydrogen is also hard to come by. Let's say we find a lava tube that is 15 meters in diameter and 100 meters long. That is about 70 thousand cubic meters, and would require about 70 tons of nitrogen to create an artificial atmosphere similar to the one we have here (we can ignore the oxygen, or which there is plenty in the lunar regolith). Bringing 70 tons of stuff from Earth is not impossible, but far from easy, even given Musk's Starship. It is much more likely that initially we'll build something similar in volume to the International Space Station, where we were able to keep a breathable atmosphere for 20+ years. Which, by the way, has a volume of only about 1000 cubic meters (out of which only about 400 m3 habitable).

patall 4y ago
My impression was that it's mostly about particle pressure and 100% O_2 at 0.2 atmospheres would also be possible. ISS keeps with the normal atmospheric pressure and 80% nitrogen but from what one reads on the internet, that is more for compatibility reasons and not because we humans cannot sustain a pure oxygen, low pressure environment, once you go all in (and stay there for prolonged times).
- credit_guy 4y ago
  A 100% O2 atmosphere would produce oxygen toxicity in the human body. Plus, it would create a huge fire hazard. Now, it's possible that we could be ok with a gas mix that's different from the traditional 21% oxygen 78% nitrogen we have here. But we don't like to experiment on humans. A different gax mix would need a lot of long term testing on animals before we'd ever consider using it.
  - dahdum 4y ago
    I believe you may be incorrect, the fraction is not the problem [1]. Apollo also ran with pure O2, even after an early accident under higher pressure [2]. > In such applications as extra-vehicular activity, high-fraction oxygen is non-toxic, even at breathing mixture fractions approaching 100%, because the oxygen partial pressure is not allowed to chronically exceed 0.3 bar (4.4 psi). 1. https://en.m.wikipedia.org/wiki/Oxygen_toxicity https://en.m.wikipedia.org/wiki/Oxygen_toxicity 2. https://www.popsci.com/why-did-nasa-still-use-pure-oxygen-after-apollo-1-fire/ https://www.popsci.com/why-did-nasa-still-use-pure-oxygen-af...

driggs 4y ago

This idea is unlikely to work unless the entirety of the pressurized volume is encased in a giant "balloon" or some sort of sealant coating the entirety of the cave's surface. Lava tubes are formed from flowing molten basalt, and basalt shrinks when it cools, forming contraction cracks. If we're producing breathable atmosphere and pumping it into lava tubes, it's destined to leak from innumerable cracks in the cave walls. And it'd presumably leak out faster than we can produce new breathable atmosphere. This differs from proposed deep "carbon capture" strategies, where we'd pump large amounts of CO2 underground for storage; in that case, the depth provides an airtight seal due to significant overburden, impermeable clays/shales, and perched aquifers above it. But lava tubes, by their very nature, are always very near the surface. That's because lava tubes - unlike other types of caves - form on the surface as molten basalt flows over it. They generally don't survive for long (geologically speaking) nor survive significant sedimentation which would bury them deeply. Lava tube caves can certainly provide shelter, and can significantly buffer temperature changes. But it would be extremely difficult to use them as an airtight biosphere. Source: I'm former cave resource manager for the National Park Service at an NPS unit with 700+ lava tube caves which was used by NASA for training and ongoing research.

more_corn 4y ago
Yeah, that’s likely the idea. The rock is more to protect from radiation, cosmic rays and punctures than to capture the atmosphere. I’d probably build it in multiple layers too. Low pressure on the outside and mounting pressure in internal domes.

falsaberN1 4y ago

Isn't lunar dust an absolute nightmare made of sharp shards of material melted/compressed from large object impacts, or something of the sort? That has to be a nightmare on the skin or soft body tissues. And devices. The idea is fun, but I'm definitely not moving there. I mean uuuuh "it is my duty to let the younger generations populate the new frontiers while I hold the fort in their absence". Yeah, let's roll with that. Knowing my luck I'd be the first Selenite to die from lung lacerations infected from recycled air because the single live native bacterium of the moon decided to get cozy in my air filter, just the day the neighbor decided to clean the rugs. Or I'd get the only non-functioning internet connection in the planet. "Satellite's fried, kid, can't do nothin' until next rocket comes with da spare!". Jokes aside, is there some sort of good reference about the internals of the Moon? I never gave it a lot of thought but it makes sense it'd have some internal structure. While I don't think there's a lot of lunar spelunkers on the job, maybe we got something with scanning or something. I don't even know where to look.

more_corn 4y ago
Correct. Moon dust is also terrible for rubber seals and other things used to create airtight environments.