The Gravity Option

--- Dan Wylie-Sears wrote:

> High-g is likely to be expensive. You need stronger
> structures to
> support more weight. To be stronger, those
> structures are then more
> massive, so they have more of their own weight to
> support. High-g will
> be found where there's a purpose for it, or if it's
> popular it will be
> found where there's the wealth for it.

I'm not so sure of this. If we assume standard
temperature and pressure for a space habitat rather
than low-pressure oxygen rich atmosphere, then the
tensile strength required to hold atmosphere inside
will probably exceed the tensile strength required to
hold the hull together under centripetal acceleration
by rather a large margin.

I suppose it would depend on the construction
technique used on the hull; for a fairly large space
station (ie large enough to rotate and give 1g
centripetal acceleration, say a radius of 895 meters
for a one-minute spin duration) it sure would be nice
to have five layers of lunarcrete, made of blocks 5m x
10m x 1m thick, overlapping and cinched together with
steel or kevlar cables. The airtightness part of the
hull could then be one or several very thin layers
interspersed with the lunarcrete. The lunarcrete
would have compressive strength and the cables tensile
strength. The combination would result in a hull
capable of holding in a normal atmosphere, provide
radiation shielding in all directions, support itself
under centripetal acceleration, be flexible enough to
absorb some fairly energetic impacts, and be
repairable. The questions then become: is there some
combination of "brick" design, materials strengths,
and overall space colony design that would easily hold
in the air and do the other things mentioned above?
and just how much acceleration could such a
combination handle before it began to exceed the
safety margin of the materials and design?

>
> Low-g will always be available just by going
> upstairs. So people well
> may commute between different gravity levels.
>
> --- In spacesettlers@yahoogroups.com,
> "sailor.barsoom"
> wrote:
> >
> > --- In spacesettlers, "Ian Woollard" wrote:
> >
> > > 0-g is just for sex!
> >
> > And sports!
> >

If the urban legends about sex in space are correct,
then 0-g sex is a team sport. ;)

Ed