[net.space] Nuclear pumped gas lasers

@S1-A.ARPA,@MIT-MC.ARPA:DIETZ@RUTGERS.ARPA (06/22/85)

From: DIETZ@RUTGERS.ARPA

I just sent a message on this subject to ARMS-D; it has applications to
civilian space, too, so I'd thought I'd reiterate here.

The idea is to make a compact, high power space based laser using nuclear
power.  I don't want to use nuclear reactions to boil water to make
electricity to drive a laser; that's horribly bulky and inefficient.
Instead, mix U-235 hexafluoride gas with some lasing medium and let the
fission fragments directly excite laser action.  We can potentially
discard waste heat at very high temperatures, allowing a very compact
high power laser.

Some applications:  (1) we can beam power to spacecraft.  (2) we can beam power to the moon.  A good orbit to use for this application is a polar orbit aligned 
perpendicular to the earth-moon axis; the orbit can be made to precess with
a period of 1 lunar month.  (3) we can fly laser powered aircraft (over
oceans!) (4) weather modification (5) pulsed UV lasers could be used to
prospect on the moon from earth orbit (maybe on asteroids too).  A pulsed
laser would need a pulsed reactor; these beasts have been built on earth
and have achieved very high instantaneous power levels (I'm not counting
pulsed reactors that make mushroom clouds).

This is potentially a near term technology, since nuclear power sources are
so lightweight (and because SDI is getting billions of dollars).

These lasers would also make, of course, frightening weapons.  Combined with
large telescopes in orbit they would allow the destruction of exposed
personnel at any give point on the Earth's surface, in seconds.  A 1 gigawatt
laser could deliver ~100x solar intensity to an area 100 meters across.
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