Engineering newsletter

[T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)]

ReplyTo   : Kevin
ReplyFrom : Timothy
Subject   : Dragonfly?

>I think this is what Kelly was trying to get at with his plasma mirror, 
>but this puts the mirror inside the ship.  I realize that I'm talking 
>about some very very complicated twists and turns, but just answer the 
>following question.  is this system physically possible?  does it 
>preserve momenergy, and does the ship slow down.  we can worry about the 
>merely difficult engineering tasks later.

Yes, it looks much like it, and I have the same comment, why not use a
simple massive mirror that works according to the dragon-fly principle.

>here's how I see it breaking down,
>
>1 photons reflecting off RM:
>
>Momenergy (very dangerous of me to toss a word around that I don't fully 
>understand.) conserved by acceleration of RM.  Ship slows down a little or 
>not at all  (photons momentum equals RM momentum and ship stays the 
>same???  but ship now has less mass  <very confusing>)
>
>2 reflected photons absorbed:
>Momenergy conserved by ship slowing down.
>
>3 electricity used to further accelerate RM.  ship slows down even more.

It would be better not to absorb the photons, but reflect them right away.
Steve showed that a long time ago.