Re: starship-design: Sail types

[Kelly St <KellySt@aol.com>]

In a message dated 5/10/98 6:43:46 PM, lindberg@olywa.net wrote:

>I have a question about starships using some kind of sail for
>propulsion.  All of the sail proposals i have seen rely on direct
>pressure for their drive.  Although i realize that what i'm about to ask
>wouldn't work for light, could a directed relatavistic particle beam (or
>solar wind) be used to create an "aerodynamic" form of thrust?  This has
>several advantages, at least at sea on earth, which is where i'm taking
>this from.  A modern sailboat sails fastest when the wind is on its
>beam.  It will sail much faster than a square rigged boat of similar
>hull, sail area, and waterline length running before the wind.
>Furthermore it is easier to control. Also, modern sailboats can sail up
>to 45 degrees (appx) into the wind.  If this could be translated to
>space it could help fix the "return" problem for star sail trips. 
>Anyway, all this is very nice, but i have no idea if it is even
>theoretically possible in space using charged particles instead of air.
>Nels Lindberg

Sail bosts can only do it because they use the leverage between the wind and
the keel to force them forward.  NO space keel, your out of luck.

Kelly