Re: RE: New idea Laser launcher/scoop systems

[KellySt@aol.com]

Brian 3:00 PM CT 3/6/96

>Kelly
>Laser launcher
>Assume the average fuel canister is the size of a 6 meter in diameter
>cylinder about 5 meters long.  I think that should hold about a hundred
>tons of fusion fuel (6Li?) but of course that would vary.

Brian
What is the density of Li?

Kelly
Don't know, don't have ref material near me.

>Kelly
>This canister is
>heavily reinforced (you'll see why), and the ends are covered in a thick
>plug of reaction mass (could be anything from fiber reinforced ice, to
>solid kevlar).  A floating laser 'tug' fires a laser at this plug of
>reaction mass.  One quick pulse to vaporise a layer off the bottom.  Then a
>heavy pulse to turn the vapor to super heated plasma.  I'E. a pulsed
>rocket.  Keep this cycle up a couple hundred times a secound.  You now have
>a laser rocket.

Brian
Cutting in here a second.  How about we make the reaction mass out of maser 
sails (many heavy (kg weight) starwisps?).  Problem is how to ionize them 
since they are design to reflect light.

Kelly
Are you proposeing the laser launcher be replaced with a maser sail system?
 That is not my intention for various reasons.

Brian
About your idea in the preceding paragraphs.  Am I understanding that the
this plasma vaporizing is used to launch the canister or does it disperse 
the fuel (good idea I think in second case).  Reading further I think you 
are trying to do both.  I don't know that you'd get the canister up to even 
a %c and the exhaust would be going in the wrong direction.  Unless, of 
course, if you were reversing the direction of the canister so that the 
exhaust would head toward TC.  Am I following you?

Kelly
No.  As I showed you should be able to get up to a good % of C.  The
canisters dock with the ship and offload fuel and are consumed for reaction
mass.  Thou during return to Sol the canisters are dethonated ahead of the
ship.

Why would you think the exaust would go toward T.C.?  It couldn't go away
from the laser.

Oh, the Explorer Class is not intented for a T.C. flight.  With a top speed
of maybe 1/3rd C its too slow.

>Kelly
>Note the canister has no internal systems.  Steering is handeled by aiming
>the beam off to one side of the base.  The uneven thrust will turn the
>canister, and subsequent pulses will thrust along the new vector.  Range is
>limited by the optical precision of the laser.  Given what a Hubble
>telescop can do over interstellar ranges.  I'll assume the system can do
>this out to 100,000 miles.

>So, if you station a laser tug every 100,000 miles or so.  They can take
>turns boosting a string of canisters.  Given orbital mechanics.  They will
>have to be continuously boosting themselves around to stay acceptably close
>to the 'Launcher' track.  (No stable orbits.)  Note that the exact
>possition of the tugs isn't important, but they must know exactly where
>they and the canisters are.  Given this system the launcher can be as long
>as you need at the moment.  If you space them out every 60,000 miles for
>100,000,000 kilometers (about a 1,000 tugs spaced from here to Mars.)  The
>average G load on a canister exiting at a speed of 1/3rd C, is E5 m/s^2, or
>about 100,000 gs.  Which seems reasonably possible for a solid block of
>reinforced metal and whatever.

Brian
What happens to the canister casing (I just looked down the page).  Instead 
of letting  the ship push the pieces to the side, can we somehow vaporize 
the casings with the plasma?


Kelly
Throw nails ahead of the ship.  They'ld hit at 100,000 k/s.  The casing and
everything else would think it hit a nuclear bomb.


>Kelly
>Laser scoop
>The ship uses a variation of this to catch the fuel canisters.  The ship
>has bow lasers that fire on the back of the canister to boost it forward
>and stear it onto the ships course vector.  Assuming the laser booster can
>function hiting the base at over 60 degrees from the center line, and can
>hit the target at 100,000 km.  The ship can 'catch' a fuel canister over
>80,000 km off to the side.  Far better than the scoop systems we were
>considering.  Which could increase the the range at which the ship can be
>externally fueled.  (Hopefully out to about 3,000 au's, since it would take
>that far for the ship to boost to 1/3rd c.)

Equations and text deleted.

Brian
I don't see how you are going to catch the canister (I admit that I'm 
skimming some of this since I have to do work very soon here).  I'll have to 
reread this idea some more but at least its a new idea.  I still don't see a 
solution for slowing down into TC though.

Kelly
The Explorer class slows down using fuel carried on board.