Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!att!cbnews!military
From: cerebus@bucsf.bu.edu (Tim Miller)
Newsgroups: sci.military
Subject: Some comments and questions on SDI
Message-ID: <10326@cbnews.ATT.COM>
Date: 18 Oct 89 02:49:46 GMT
Sender: military@cbnews.ATT.COM
Organization: Boston University
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From: cerebus@bucsf.bu.edu (Tim Miller)


	On the subject of SDI, there is one thing that bothers me.

	Why is it that 90% of the media's attention is focused on the use
of lasers ar beam weapons instead of (IMHO, more feasable) 'kinetic energy'
(KE) weapons?

	I have also seen this tendancy toward ignoring KE weapons in the
scientists that are researching the weapons as well as those that are
criticizing the initiative.  Research _is_ being done in KE weapons, but
_my_ impression of the work is that it is taking a back seat to beam weapon
research. 

	Is there something so attractive about a laser weapons system that
scientists and laymen alike ignore the possiblility of the so-called 'smart
rocks' and 'orbiting machine-guns' (sattelite linear accelerators throwing
plastic pellets at about 7-10 miles per sec)?

	Beam weapons are a problem.  The eat power; they break down easily
(ask the guys with the NOVA laser-- it fires once, maybe twice a day); and
are expensive to repair and maintain.  Does this sound like a good defense
system?  On the other hand, a smart rock only has to be launched,
preferrably in bursts, like a shotgun blast; yeilding a much better chance
of striking the target (and the rock need only graze the missile; I read
that it had been calculated that even a grazing impact at 10 mps [an
average orbital collision velocity] is like setting off a hand grenade
strapped to the stressed aluminum skin of an ICBM).  

	Smart rocks could operate as a first line, taking out ICBMs at the
end of their boost phase; linear accelerators could operate as a second
line, pinpointing and shotgunning individual warheads.  Even light plastic
pellets 1cm in diameter gouge out craters in blocks of aluminum that are
inches deep in tests carried out at 4mps-- much slower than what would be
implemented. 

	Ask anyone who hunts any kind of bird; they'll tell you that a
shotgun is a better weapon for a flying target than _any_ rifle, no matter
how good your aim.

	So why does the design philosophy of SDI seem to lean toward beam
weapons at the near exclusion of all else?

					Timothy J. Miller
					cerebus@bucsf.bu.edu