If we colonize the moon, why wouldn't we build underground?

Question

As I read about the planned 2020 return to the moon, no one ever suggests creating our habitat underground. This seems to be a logical option: we'd get shielding from radiation, we'd need less building material, there's less risk of decompression (you can't poke a hole in 50 ft. of lunar rock), and we'd be closer to the core where we can tap into geothermal energy. Fellow geeks: what am I missing? Why isn't this a good option?

Answer 1

We would build underground eventually ... but where would we live while we were digging our new homes/cities? I doubt we'd want to live in a spaceship for the months and years it would take to build underground ... so we'd still need a good, easily transportable 'temporary shelter' like tents to live in above ground while we 'dig' our new places to live. After all, that 'commute' back to earth is really too far to make daily ...

Answer 2

Here's a better idea, build it on the surface, but cover it with Moon dust and so on. It's more simpler than digging underground.


There are plenty of design concepts on underground Moon settlements, it even already suggested since the 1960's (you can see the designs in 2001: A Space Odyssey).

However the problems are similiar on why we don't see many underground settlements, they are:
- it cost more than above ground settlements
- most people don't like to live in underground settlements


You're correct that it provide shielding from radiation and need less building material for shielding radiation.

However, the Moon rocks aren't airtight and there's no indication of any useful geothermal energy.

Answer 3

I think it would be a blend of both strategies. I mean if you are going to excavate you need to do something with the tailings.

The big question is "Why would we colonize the moon?"
To justify such a venture there has to be some economic, political or military advantage to it. The moon is almost entirely the same rock as we find in the Earth's crust, and we have plenty of places more hospitable that we have not bothered to colonize on our own planet.

If all we are doing is going there to collect a few samples and brag the habitat is nothing more than a high tech prospector's tent.

Answer 4

Good question. I would guess that the advantages, as NASA sees it, would not outweigh the cost of the effort. For one thing, the rock is full of fissures and would not be air tight, so they would still have to transport all the materials necessary to build an airtight enclosure. And cutting into the surface would have a significant cost both in terms of heavy-duty equipment and energy to run it. Your point about radiation shielding is a good one, but reflective, air-tight, metallic domes for living quarters are going to have a lot of inherent shielding already, and that can be further enhanced by placing them in a deep crater where they will be in permanent shadow and thus shielded from direct solar radiation. As for geothermal (I believe that would be "lunarthermal" energy) the moon's core is solid and retains little useful latent heat -- they would have to go down many miles at great cost to reach useful temperatures. Certainly going underground would offer safety from meteoroid strikes, but that may not be a major concern, given their relative rarity.

Answer 5

Maybe it's a good option, if the wars on this planet don't stop any time soon. But otherwise I don't think that I want to live on the moon or in the underground of the moon. All I want to do is look up and see the moon. The idea is interesting though.

Answer 6

Going underground has all sorts of huge advantages.

As for why it's not in the planning stage yet, I would guess that at this stage of the game they are not yet planning on having the excavating equipment. Or on having equipment for any large construction project. That'll come later.

The Orion spacecraft and equipment will really be little more than what the Apollo spacecraft had. More advanced, yes. But not much bigger.

Answer 7

Because it is easier, cheaper to build a lunar base on the ground that under the ground, however, I wouldn´t discard that option once the first human base it´s there. Surely once established, they would want to do a lot of new and better things, like digging the ground and building underground bases.

Answer 8

It's said that building a 1m underground costs building a 10m on the ground. That explains why people prefer to go up but not down - simply because it's too expensive to do underground.

Answer 9

I think it is a good idea, but any equipment for digging such as tractors or whatever would be extremely difficult to transport to the moon because of their weight.

Answer 10

I don't think there is any geothermal activity on the moon.