Radiation Fatigue?

Actually, I'm currently thinking a cylindrical or cone-shaped
window running down the central axis of a island 3 shape might
be a good design.

That way, the radiation shielding of the metal/ground is all
around you, and the glass is in a compressive loading rather
than tensile loading (I think it would like that better; then
any cracks will probably hold together, whereas with O'Neills
concept of having it around the edge- it tends to explode
outwards- tends to, although you try to stop it of course.) The
air pressure keeps it in place rather like a huge glass arch-
and the rotation forces are negligable anyway.

You'd let the sunlight in through one end- probably a parabolic
mirror outside would give you a controlled amount of light.

Gains you lots of land, and helps with the radiation problems
too.

Ed Schonert wrote:

> Our problem is that we haven't settled on a basic shape for the first
> few colonies. Will they be spheres, toroids, dumb-bells or cylinders?
>
> If we go right to the large cylinder for first colonies I believe the soil
> for
> the land area can provide the shield. Circumferential tension cables
> can contain the atomosphere & the centrifugal force tending to make
> whole thing fly apart. This is analogous to how suspension bridges
> use far less steel than truss bridges for the same span.
>
> If the radiation turns out to cause metal fatigue in the cables they could
> be put "above" ground with radial cables thru soil to outer skin every
> few meters.
>
> Beauty of this approach is that we can forget that 1 kg of regolith shield
> per square cm skin area in Al Globus's 7-18 forwarded message.

Still, air pressure is atleast twice that... And it might be
easier to just put the habitat in a radiation-shield 'cave'
that doesn't rotate.

> I hate to see waste & if we build toroid, sphere or dumb-bell shaped
> colonies with all that radiation shield then switch to cylindrical with no
> radiation shield wouldn't it have been a great waste?

Not necessarily greatly so. Always melt it all down and start
again. The automation to do this is a wonderful thing.

> Hallelujah - Praise Spacesettlers ! ! ! Ed S.
>

--
- Ian Woollard (ian.woollard@...)

"Is a planetary surface the right place for an expanding
technological civilization?"
- Gerard O'Neill