Different type of habitat

From: spacesettlers@yahoogroups.com
[mailto:spacesettlers@yahoogroups.com] On Behalf Of Darren

> http://www.analogsf.com/0603/SunofSuns.shtml
>
> The idea is an intriguing one, a habitat thousands of kilometres
> wide with hundreds of smaller (down to house sized) structures
> in it that spin to provide custom spin-grav to the inhabitants
> or not if you are in need of micro-g.

snip

> ... the spin would need to be maintained because of drag

That's the problem that I have with the idea. I don't know what the air
drag would be on a rotating cylinder 4 miles in diameter and 20 miles
long, but I imagine it would be tremendous and that the energy
requirements to overcome it every second of the structure's existence
would probably not be economically sustainable. I think the only reason
why keeping such structures rotating in space is considered at all
viable is because of the assumption that this rotation is taking place
in vacuum.

But if one wants to talk about mega-habitats made from Buckytubes or
diamondoid, I think there are other more viable designs. Here's one:

http://www.iase.cc/openair.htm

http://www.orionsarm.com/whitepapers/SpaceRings.pdf

Of course I'm known for the position that reflecting natural sunlight
with mirrors for illumination is better than artificial illumination, so
I would replace the central light source and its associated optics with
a mirror arrangement much like that for the Stanford Torus. But with a
twist which takes us to a situation SF fans might find interesting.

The Stanford Torus has two rings of mirrors which reflect light from the
primary mirror out to the interior of the torus.
(http://members.aol.com/sandycombs/torus1.jpg) The rings are about half
the diameter of the torus, so two rings of mirrors are needed, with the
mirror segments staggered in such a way that the beams of sunlight
coming down from them dovetail.

Now in this mega space-ring design, we'll need to have a day/night
cycle. That could be accomplished by swiveling the mirrors, but there's
something else we could do which would eliminate the need for moving
parts. We could have one ring of mirrors instead of two. Now we have
gaps in the beams of sunlight projecting outward, and 50% coverage. We
arrange for the ring of mirrors to rotate slightly more slowly than the
floor of the habitat, so that sunlight and shadow passes by a given
point in a 24-hour cycle.

This winds up looking very much like Larry Niven's Ringworld, with its
shadow-squares. Such a structure, while at a much smaller scale than
what Niven proposed, would scarcely be visually distinguishable from it,
if standing on its surface. Such a structure might be a good deal more
realistic, though, since it only requires materials beyond our present
ability to create, instead of ones totally beyond present scientific
knowledge.

Regards,

Mike Combs