Asteroid use

--- tntucker@... wrote:
> --- In spacesettlers@egroups.com, Marcel Williams
>
> wrote:
> > MW: No one has ever produce 1G similated gravity
> > habitats in space either-- but physics is physics.
> And
> > building a light sail would be a trillion times
> > easier than building a fusion rocket, or even a
> mass
> > driver, IMO. And in an earlier post, I proposed a
> 1
> > billion dollar annual NASA research program over
> the
> > next ten years to test and to build lightsails in
> > space.
> > But if you want to learn more about the light sail
> > concept, you can visit my lightsail webpage at the
> > following URL:
> >
> http://members.telocity.com/~hydra9/lightsails.html
> >
> > Marcel F. Williams
> > 1/6/00
> >
> Marcel,
>
> Have you considered how light or solar sails could
> be constructed out
> of durable materials such a glass and aluminum that
> we could find on
> the moon?
>
> I believe that NASA studies of hydrocarbon materials
> limits their
> life to less than 5 years due to atomic oxygen from
> the sun.
>
> Regards,
>
> Tom Tucker
>
MW: Drexler light sails are made out of aluminum that
is only 0.1 micron thick. However, aluminum could be
made as thin as 0.02 microns thick before light would
begin to pass through it. And Drexler believed that
his sails would last somewhere between 30 to 300
years.