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Path: utzoo!watmath!clyde!cbosgd!ihnp4!hplabs!oliveb!3comvax!michaelm
From: michaelm@3comvax.UUCP (Michael McNeil)
Newsgroups: net.space
Subject: Re: Fusion for Rockets (actually, Lasers for Rockets)
Message-ID: <455@3comvax.UUCP>
Date: Fri, 21-Mar-86 00:57:21 EST
Article-I.D.: 3comvax.455
Posted: Fri Mar 21 00:57:21 1986
Date-Received: Sat, 22-Mar-86 22:17:50 EST
References: <[MC.LCS.MIT.EDU].848824.860312.KFL>
Reply-To: michaelm@3comvax.UUCP (Michael McNeil)
Organization: 3Com Corp; Mountain View, CA
Lines: 32

In article <[MC.LCS.MIT.EDU].848824.860312.KFL> KFL@MC.LCS.MIT.EDU
("Keith F. Lynch") writes:
>
>>Interstellar ships could be beam powered (laser sails) ...
>
>  Perhaps a laser could be used to vaporize the reaction mass, as I
>assume you meant in the previous paragraph, but as for laser sails,
>how would the starship decelerate as it approaches its destination?

I've heard of a proposal (sorry, I don't recall the reference) by
which a stationary-laser-powered sailship would extrude a long wire as
it entered interstellar space, then use a particle emitter to build up
an electric charge.  The ship would then interact with the galactic
magnetic field, and swing around in a very large circle.  Eventually,
it would approach the destination star *from the other direction*.  
At the appointed moment, Earth would turn on its lasers again, and
decelerate the ship as it enters the target system.  (Of course,
civilization better not have fallen in the meantime! :-) )

-- 

Michael McNeil
3Com Corporation     "All disclaimers including this one apply"
(415) 960-9367
..!ucbvax!hplabs!oliveb!3comvax!michaelm

	What a wonderful and amazing Scheme have we here of the
	magnificent Vastness of the Universe!  So many Suns, so
	many Earths ... !  
		Christianus Huygens, *New Conjectures Concerning the
		Planetary Worlds, Their Inhabitants and Productions*,
		c. 1670