ARMS-D-Request@MIT-MC.ARPA (Moderator) (11/21/85)
Arms-Discussion Digest Wednesday, November 20, 1985 4:49PM
Volume 5, Issue 26
Today's Topics:
SDI Evolution
SDI Feasibility
Cartoons of SDI
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Date: Tue, 19 Nov 85 23:10:20 PST
From: Richard K. Jennings <jennings@AEROSPACE.ARPA>
Subject: SDI Evolution
Re comments that SDI will evolve -- I was under the impression
that that was the idea. SDI funds are being spent upon feasibility
research. My (personal) opinion is that the end SDI system (when is
*end*?) will *not* be scaled down at all, because of the HUGE commercial
inverstment about to be made by commercial companies in Space.
Nobody foresaw how integrated circuits would take off, once
they, engineered into products, ignited the desires of consumers with
plastic cards. SDI is priming the pump -- essentially funding the
military-INDUSTRIAL complex of this country to get used to the idea
of *routine* space operations.
People have a habit of learning from mistakes, and DoD (as usual)
is subsidizing its contractors (who also sell commercially) to make
some big ones. If I ran the USSR, whether I belived in 'Star Wars' or
not, I would be quite concerned.
To say that SDI will degenerate into an antisatellite program
does not seem to be based upon recent technological trends.
In another note, one point of agreement we might have with the
Soviets is to design all our weapons to defend against 1) errant asteroids,
or 2) enraged aliens. The latter might be a consequence of the
violence on television which should now be about 2 light decades out.
Depending on you views of ETI, it is only a matter of time before our
beacon is detected, and the decision is made to contain us for the
benefit of the Galaxy/Universe/? If we wait until the ships show up,
it may be too late. After watching all our TV, I don't think they will
want to reason with us.
Rich.
(I have been working very hard today, and these views may not even be
my own, much less of anybody else).
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Date: Wed 20 Nov 85 12:51:46-AST
From: Don Chiasson <CHIASSON@DREA-XX.ARPA>
Subject: SDI Feasibility
A recent article in Science (8-Nov-85, vol. 230, no 4726, pp.
646-648) casts doubt on the feasibility of x-ray lasers as weapons for
the boost phase portion of SDI for a number of reasons: inadequate
range and power, impracticality of pop-up systems, and others. It is
noted that some of the problems could be eased if there were x-ray
lasers powerful enough to blast through the atmosphere by the process
known as 'Bleaching'. The author then notes that '... some experts
say that this can be accomplished only if the brightness of present
x-ray laser beams is increased by more than ten orders of magnitude -
an extremely daunting scientific challenge.' Ten orders of magnitude
is indeed challenging!!!
I do recommend the article. Indeed, anyone interested in arms
discussion should read Science regularly. It frequently has relevant
information. For example, the topic of using aircraft to carry ICBMs
recently came up in ARMS-D. About the time of the MX basing debate,
Science had a discussion of this possibility. (Sorry, I don't know the
exact issue and page. If anyone is interested, I can look up the
series of articles.)
On the topic of SDI, the IEEE magazine Spectrum, has a special
report consisting of a series of three articles: 'Mind-Boggling
Complexity', 'Exotic Weaponry', and 'Debating the Issues' (September,
1985, pages 34-64). These give excellent discussions of many aspects
of SDI, both technical and policy. I particularly enjoyed the
back-of-the-envelope calculations.
Donald Chiasson
(Note: I am not an employee of DREA, nor are these comments presented
as the opinions of DREA or my employer.)
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Date: Wed, 20 Nov 85 15:59:02 EST
From: Will Martin <wmartin@BRL.ARPA>
Subject: Cartoons of SDI
I watched part of a PBS show last night that was tacked on to the end of the
excellent series "WAR", but was not part of that series, and which was a
review of the SDI pro and con arguments. It was illustrated with the animated
depictions of SDI we have seen now a hundred times or so, at least in
excerpts. I have a few questions about these cartoons, and I hope ARMS-D
readers can inform me about them:
1) Who made these, anyway?
2) One scene depicts a flight of Soviet missles rising up out of the
atmosphere. They are shown as full-size rockets, with exhaust flames
coming out of the tail. I thought that these were staged missles, and
by the time they got out of atmosphere, they were purely ballistic, with
no propulsion engines going any longer, and also that they'd be just
an upper stage or MIRVed warhead unit (maybe with small attitude
thrusters?). Am I wrong? How much of the original missle gets how far
on the trajectory, anyhow? (Use the common or major Soviet land-based
missles for examples here, please. It would be interesting to know
the equivalent info for the MX and Minuteman, though.)
3) The scene showing lasers hitting the missles also shows them blowing up
in a flash of light, and no debris left. (I believe I am remembering this
correctly, but I might have it confused with the next example.) The
scene showing the impact-defense units shows the projectiles hitting
Soviet missles (again, complete missles, not just warheads), and,
interestingly, does not depict a fireball or explosion, but a
star-shaped burst pattern coming out of the middle of the target. I
was not sure if this was meant to be unexpended fuel coming out of a
hole and freezing into a crystalline pattern, or just was a stylized
version of an explosion.
Anyway, both of these seem to be wrong to me, for several reasons:
a) The targets, at these stages of intercept, should be warheads alone,
right? Would they be still clustered in the single warhead, or already
separated into individual MIRV warheads? [What's the correct terminology
here? I think I'm using the term "warhead" incorrectly somewhere.]
b) It was my impression that the laser hits would NOT cause any
explosions, but merely burn a hole or several into the warheads and
damage them so that they would not explode if they reached their
intended targets, or so that their guidance and/or stabilization systems
would fail and they would either burn up on reentry or hit some random
point (again without exploding?).
c) I thought that the impact-defense munitions were non-explosive
projectiles that would work by striking the incoming warheads, thus
causing physical damage and the warhead's failure as above. This WOULD
cause debris, but the impact would not be that dramatic, I would think.
They shouldn't be shown hitting complete missles, should they?
Am I right in these suppositions and interpretations of the proposed SDI
system operation? If so, why would these "sort-of-semi-official"
animated representations of the systems show them so wrongly? It doesn't
cost any more to draw something right than to draw it wrong, after all!
And a couple follow-on queries: Let's assume a working SDI in place, and
an attack. The first stage of defense is the lasers, right? They put out
of action a certain number of warheads, but these warheads still keep
coming along their trajectories, since the laser beam cannot actually
deflect them off course, but damages them by burning, if I have this
right. So how do the later stages of the defense distinguish between the
inactivated or "destroyed" warheads and the ones the lasers missed? Or
do we have to hit ALL the warheads with impact projectiles just to make
sure that a working one doesn't get through? This seems to make the
laser stage sort of useless, doesn't it? It increases the computer load
and capability requirement of the impact-defense stage enormously,
because the initial defense doesn't "filter" or "attrit" out what it
really succeeded in hitting. It just doesn't sound right. Maybe I have
this all screwed up in my mind...
What about the damaged warheads? They still hit amosphere and burn up,
right, even if they are in tiny pieces by then? So there is an amount of
radioactive material spread out across the upper atmosphere. What is the
projected radiation dose expected to result from this? (I'm sure it is
far less than what would result from nuclear explosions at the targets,
so I'm not saying that this is a good anti-SDI argument. It is just that
nobody ever seemed to mention this, that I know of. People seem to think
that stuff zapped in space disappears magically, instead of realizing
that it rains back eventually.)
I'd like to hear discussions and be enlightened on any of this I am
wrong about. There just seemed to be a lot subtly wrong with that
animated depiction, and I'd like to know if it really was wrong or if I
just am off-base in my impression.
Regards,
Will Martin
UUCP/USENET: seismo!brl-bmd!wmartin or ARPA/MILNET: wmartin@almsa-1.ARPA
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End of Arms-Discussion Digest
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