Lunar Dome Question

From: "mgellis2"
To:
Sent: Sunday, January 27, 2002 2:36 PM
Subject: [spacesettlers] Lunar Dome Question

[snikt]
> How large could such domes be? I imagine it would not be too hard to
> build domes a couple of kilometers across, especially in the lunar
> gravity, but could we actually dome over craters fifty or a hundred
> kilometers across (and several kilometers high)? Any engineers out
> there want to tackle this one?
>

I think that the main factor limiting the size of the domes is not gravity,
but rather internal atmospheric pressure - at least, that is surely the main
factor limiting the size of free-floating space colonies. In fact, the
tendency of a very large dome would be to blow up rather to crumble down.

However, if you provide a "counterweight" for the internal pressure - for
instance, by doing your dome *extremely* heavy in order to make a downward
pressure equal to the upward pressure from the air - then you could have
domes of theoretically unlimited size. Of course they would not be "domes"
in the geometrical sense of the word; instead, they would be flat lids
covering the craters. As for lateral air pressure, I think that the thick
rock walls of a crater rim would suffice, though of course I'm no civil
engineer/geologist and each case should be analyzed by that kind of
specialist.

The "extremely heavy domes" perhaps could be made with 1 or 2-meter thick
lunar glass plates. (Assuming that glass so thick can still be made
transparent.) Incidentally, that would also work as a radiation shield.

[snikt]
> Thanks.
>

You're welcome.

> Mark
[snikt]

Lucio