A Science Vision report about living on the Moon - how it can be done.

From: Chris Smyth

Thanks to you and Ed for that clarification. Your responses confirm
my intuitive understanding of gyroscopic behavior. This understanding
is the reason I felt that a Stanford Torus with its axis oriented
along the plane of the elliptic could be actively repositioned to
always present one side to the sun. This would require an adjustment
of 360 degrees every 365 days (slightly less than one degree per day).

But one of the things you should get out of this is that the gyroscopic
effect will make that ~1 degree per day turn problematic. It would
require the continuous application of force, which would result in an
exorbitant bill for the required reaction thrusters.

O'Neill gets around this problem with his Island 2 and Island 3 designs
by making them 2 linked cylinders rotating in opposite directions so
that the net angular momentum is 0. I've never seen it proposed, but I
suppose one could link two Stanford Tori together and do the same thing.
The Bernal Sphere rotates its radiation shield in the opposite direction
to accomplish the same thing, and I also suppose that same solution
could be applied to the Stanford Torus (although now the shield would
have to be stronger since it would come under at least 1/10 G of
centrifugal force.

But I'm not sure that the elimination of that oval, 45degree angle
mirror would pay for such additional engineering complexities. Bear in
mind that its construction would be neither complicated (due to its
structural simplicity) nor expensive of materials (due to its
flimsiness).

I still wonder whether such an orientation would be advantageous in
terms of both having a solar panel shield to provide copious and
continuous amounts of electrical power for the Torus (and possible
transmission to Earth) as well as allowing for internally generated
heat to be bled off through the structure of the Torus itself, since
it would forever be in the shadow of the solar panel.

But remember that the Stanford Torus would be edge-on to the sun, which
is pretty favorable from a heat-dissipation standpoint.

I don't believe the proposals for using sunlight (directly or via
mirrors) to illuminate the Torus interior are practical due to the
need for radiation shielding and concerns about the structural
integrity and air-tightness of a Torus with large glass skylights. I'm
strictly an amateur when it comes to space station design so if anyone
has any thoughts on this please let me know.

The original researchers certainly seemed to feel that use of natural
sunlight could be practical. Bear in mind that the complications of
chevron shields will only exist for smaller space habitats. Larger ones
will not require any shielding separate from the structure itself. The
only alternative to natural sunlight for things like agriculture is
much-larger solar PV panels and artificial illumination (sometimes red
LEDs are proposed for the sake of efficiency). But I have a hard time
seeing PV panels and artificial illumination by the square mile as not
being a lot more expensive than aluminized Mylar and glass by the square
mile.

Regards,

Mike Combs