Radiation Fatigue?

On Monday, July 22, 2002, at 12:05 PM, Ed Schonert wrote:

> 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.
>
The biggest problem, in my mind, with cylinders is that rotation around
the long axis is unstable. A rotating cylinder with more-or-less
uniform mass distribution wants to rotate around the short axis -- this
is not good. One way around this is to hang weights on long cables so
the mass balance favors rotation around the long axis, but don't let
your spacecraft run into these! The could be used as a transportation
system though -- you go out along one to the right place, let go at the
right time, and you've got a lot of velocity in the (hopefully) desired
direction.

The dinosaurs were destroyed by an asteroid because they weren't
space-faring. It's almost as if Gaia then thought "Well, dinosaurs
worked pretty well, but space-faring is necessary. Maybe I'll should
try mammals this time." Humanity is now developing systems to detect and
deflect asteroids, and could build orbital space colonies to spread
beyond Earth to insure life would survive a planetary catastrophe.

Al Globus
CSC at NASA Ames Research Center
http://www.nas.nasa.gov/~globus/home.html