Re: Retro sailing difficulties

[KellySt@aol.com]

>> if anyone can figure out how to bounce the maser beam back
>> toward TC after it hits the plasma, I'll gladly scrap the 
>> accelerating-the-plasma  with-the-converted-energy idea. 
>> which would save us from having to use microwaves, and 
>> help out with our heat load.

Arange the catcher mirror so that it focuses the reflected maser beam (from
the ring sail) on the plasma, but does not inact with the maser reflected
back from the plasma.  If that reflected maser beam hits a flat mirror (or a
curved or conical mirror) that doesn't reflect it onto the ring sail.  The
reflection from the plasma will push backwards toward Sol.

I thought of a problem with the ring sail thou.  It would focus the maser
ahead of the ship.  To realize this think of the thrust vectors on the sail
from the reflections, vs the vectors from the cables from the ship.  If the
thrust vector angles are angled more forward than the cables, they would pull
the sail forward.  Which would colapse the sail.  Since the reflected maser
beams would be angled ahead of the normal vector at the point of reflection
(equal angles of incidence and reflection) They would focus even farther
ahead of the ship.

I had thought of a was of using another sail to reflect the masers back
outward for collection behind the ship, but that would probably not work due
to beam reflections off the plasma stream.

I suppose you could have the beam interact with the injected plasma in front
of the ship.  This would blow the high energy plasma stream backwards toward
the ship.  For later reflection off a magnetically or electrostatically
charged forward shield/pusher plate.

Kelly