"Ross A. Finlayson" wrote:
> Solar sails are good. When they are far from the sun (a towed sun?
> elliptical speculation...) then they could shed or fold the sails, deploy
> Bussard ramjet, and then scoop interstellar hydrogen.
>
> It would be better to have some kind of "warp" drive, some time or other
> dimensional travel based thing to simply automatically move from point a to
> point b, for interstellar travel.
>
> In terms of intra-solar travel, solar sails are great because they require no
> reaction mass. This means they could maneuver indefinitely around, barring
> space junk collision or other regular or irregular space travel dangers.
> Satellites with solar sails and gyrodynes could have very very long
> lifespans. Things should be built to last thousands of years.
>
> Spike Jones wrote:
>
> > >...He suggested star sailing was not only impossible, but absurd,
> > since solar gravity is stronger than light pressure, assuming a
> > single atom thick layer of aluminum, and furthermore, solar
> > gravity stays stronger than light pressure, regardless of the
> > distance from the sun, since both drop off as the square of the
> > distance.
> >
>
> Hmm... solar sails. These kinds of things are easier said than done.
>
> Ross Finlayson
If light powered spacecraft interest you, you might try this url for a system
which looks like it might actually be implemented due to its several orders of
magnitude decrease in launch costs.
http://www-aero.meche.rpi.edu/curriculum/tavd/
Dennis Roberts
droberts@a-o.com