Technotranscendence wrote:
>
> On Friday, July 23, 1999 10:22 PM Ross A. Finlayson <raf@tiki-lounge.com>
> wrote:
> >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.
>
> If my memory's correct, NASA already did have at least one satellite with
> panels on it that used light pressure to maneuver. This was in Earth orbit.
> Anybody else recall this?
>
> It's too bad no one has yet placed one in space. (A few groups have come
> close.)
>
No, they've had several satellites that MEASURED light pressure, including the Pegasus satellites. None have used solar sails for propulsion. They've tested some solar powered ion and plasma propusion systems for station keeping use.
Mike Lorrey