Space habs buried under the moon's surface

One problem: Even in 1/6 G, a habitat sized for any decent population at all would require truly massive and strong bearings. Even an orbital habitat the mass of Island 3 would have very small and flimsy bearings in comparison (and that's with the assumption of a despun section; we might could get along without one), since under normal circumstances they would come under little to no load.

I got into this discussion with someone on Usenet who insisted that his lunar design had no bearings at all. I told him that since he had posited a "maglev" type of approach, he was simply assuming magnetic bearings, and had not eliminated the need for bearings from his design.

Second problem: If something ever went wrong with the systems which made up for frictional losses in the bearings, in the orbital case the gravity would become less and less in a asymptotic fashion. In the lunar case, same, only past a point, things would start sliding down to a "wall" that eventually becomes the new "floor", with catastrophic consequences for interior furnishings.

Read O'Neill's list of advantages of orbital habitats over habitats built on celestial bodies:
http://space.mike-combs.com/spacsetl.htm#advantages

The only way lunar habitats would be better than O'Neill habitats (even assuming the same "gravity") was if the cost savings in not having to lift materials out of the lunar gravity well were so great that they overcame the economic disadvantages of being on the surface. Given the lunar mass-driver assumption, I don't expect that to be the case.

I can see a revolving lunar gymnasium, useful for people fixing to head back to Earth. But nothing on the scale of even the more modest habitats O'Neill envisioned for orbit.

Regards,

Mike Combs

From: spacesettlers@yahoogroups.com [mailto:spacesettlers@yahoogroups.com] On Behalf Of sraj
Sent: Wednesday, June 23, 2010 1:06 PM
To: spacesettlers@yahoogroups.com
Subject: [spacesettlers] : Space habs buried under the moon's surface

A major problem in designing space habs orbiting the Earth/Moon system is
the amount of shielding material that has to be launched into space. Why not
start with rotating space habs buried under the Moon's surface? The 'ground'
will have to be tilted by about 10 degrees to counter the Moon's gravity.
Illumination will be through electric lighting.