KFL@MC.LCS.MIT.EDU ("Keith F. Lynch") (03/13/86)
Power can be supplied to all points in the solar
system by kilometer-size lasers.
Since it takes hours for a signal to travel to or from the outer
solar system, any such laser would have to know just where the target
will be. This would make any sort of interplanetary travel except
prearranged computer controlled travel quite difficult. This is the
trolley-car approach. Perhaps this is the way to go, but it has a lot
of restrictions.
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?
Fusion limits you to about 10% of the speed of light.
The starship could pick up fuel, i.e. interstellar hydrogen, en
route. As such, it can get a close to the speed of light as you like.
...Keithmichaelm@3comvax.UUCP (Michael McNeil) (03/21/86)
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