Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU Path: utzoo!decvax!bellcore!ulysses!cbosgd!ucbvax!XX.LCS.MIT.EDU!ARMS-D-Request From: ARMS-D-Request@XX.LCS.MIT.EDU (Moderator) Newsgroups: mod.politics.arms-d Subject: Arms-Discussion Digest V6 #102 Message-ID: <8606092042.AA17171@ucbvax.Berkeley.EDU> Date: Mon, 9-Jun-86 15:30:00 EDT Article-I.D.: ucbvax.8606092042.AA17171 Posted: Mon Jun 9 15:30:00 1986 Date-Received: Mon, 9-Jun-86 21:41:42 EDT Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: ARMS-D@XX.LCS.MIT.EDU Organization: The ARPA Internet Lines: 221 Approved: arms-d@xx.lcs.mit.edu Arms-Discussion Digest Monday, June 9, 1986 3:30PM Volume 6, Issue 102 Today's Topics: Re: A Star Wars Query "A Star Wars Query - Alfred Beebe " SDI countermeasures Basis for SDI Assumptions? ---------------------------------------------------------------------- Date: Thu, 5 Jun 86 22:45 EDT From: "J. Spencer Love" Re: A Star Wars Query The mirrors on our satellites might work because they are larger, or several satallites simultaneously focus on a single target. (The former seems likely; the latter unreasonably complex.) Ground based lasers that can shoot down satellites have to be in phased arrays. Sufficient energy density (in Watts per square meter, or joules per second per meter squared) can overcome any mirror that could protect a warhead, but such high energy densities can turn the atmosphere to plasma, blocking the beam, or destroy the lasers that are generating the beam. The trick is to put lots of units in parallel, and point them all at the same target. A laser farm tens of meters square could focus on an orbiting mirror several meters in diameter, and if the aiming system is good enough, focus on a small area, perhaps a square centimeter, on the actual target. If the mirror is to do significant aiming, perhaps it also would be an array in the manner of the fresnel lens: a large grid of aimable mirrors, or some more esoteric technology such as the special reflectors discussed in Scientific American recently which can unscatter light, and which might be steerable by electric fields in a manner similar to liquid crystals. (If anyone actually knows about this technology and can talk about it, please do.) The massively cooled mirror approach can't tell the whole story because power densities sufficient to disable the warhead in a small fraction of a second may be needed to prevent the warhead from being able to take evasive action (an obvious countermeasure improvement to warheads, with all kinds of interesting ramifications). Energy densities high enough to cause a part of a possibly mirror-coated surface to explode and kill the warhead with the shock wave are not going to be impressed by fancy colling systems. ------------------------------ Date: Fri, 6 Jun 1986 01:57 EDT From: LIN@XX.LCS.MIT.EDU Subject: "A Star Wars Query - Alfred Beebe " From: DonSmith.PA at Xerox.COM ... there are so many weaknesses of this sort in the SDI systems proposed thus far... that one can't help but wonder what are the real motives and goals of the promoters of SDI. In my view, the real goal of SDI promoters is the achievement of a leak-proof defense against arms control. ------------------------------ Date: Friday, 6 June 1986 00:29-EDT From: decwrl!sun!peregrine!falk at ucbvax.Berkeley.EDU (Ed Falk) To: ucbvax!XX.LCS.MIT.EDU!ARMS-D-Request at ucbvax.Berkeley.EDU re: SDI Countermeasures > > There is an aspect of the SDI plan that I have never heard > mentioned, that seems as though it would be a fatal flaw. ... If we assume that we can > (among all our other priorities) create mirrors that render our > vehicles safe, then we should assume that they can create mirror > surfaces that render THEIR vehicles safe. > No, you're not missing anything. Dr. Robert Bowman is an alumnus of my alma mater (RPI) and was at one time the director of "star wars" research back in the days when it was a reasonably-priced research project. When Reagan latched onto the idea, and started pouring billions (or is it trillions?) into the project, Dr. Bowman quit in disgust and now tours the country lecturing AGAINST SDI. He came to RPI about a year ago and gave a talk on the subject. This is the gist of what I can remember. Some think-tank or another came up with a very cheap, reliable system of stopping russians missiles before they reach the U.S.: What you do is deploy a soldier with a machine gun next to each Russian missile silo. When the soldiers see missiles being launched, they empty their machine guns into the boosters, causing them to explode. The problems with this scheme are obvious. You can only deploy it if the Russians let you, and they can take it out any time they want to. Dr. Bowman says that SDI has the same disadvantages -- you can only deploy it if the Russians let you, and they can take it out any time they want to. The main difference is in expense. Dr. Bowman then went on for an hour and a half explaining how the Russians can stop SDI and how hard it is to implement in the first place. For SDI to work, you can hit a Russian missile while it's being boosted, while it's in flight and while it re-enters. Boost-phase intercept is the most desireable, as the rocket is most visible at that point and you get the warheads before they mirv -- one target instead of ten. The problem with boost-phase intercept is that you need to penetrate the atmosphere where the boost takes place. You need to keep a steady laser beam on the booster for long enough to burn through the side of the rocket and ignite the propellant. It costs billions to build a laser that can do this. It is far cheaper for the Russians to build the boosters out of some shiny material which will reflect the laser and/or rotate the booster as it flies so that the heat is dispersed around its perimeter instead of being concentrated in one spot. SDI space mirrors must be optically perfect in order to keep a beam focused properly. They must be on the order of 99.9% reflective so that the laser will not destroy them. Making a booster shiny enough to not be destroyed is a much easier task. Also, space mirrors are extremely easy to destroy. A handfull of sand or a thimble-full of sewing machine oil put into a retrograde orbit with the mirror will destroy it's reflective properties enough so that the laser will destroy the mirror instead of bouncing off. Another thing Dr. Bowman pointed out was that although SDI weapons will be marginally effective against enemy rockets, they are very effective against enemy SDI systems. This means that if the Russians have an SDI of their own, they could take ours out at a moment's notice. Reagan is either confused or lying when he says he'll share the technolog with the Russians. Dr. Bowman also feels that SDI is destabilizing in that it will encourage the Russians to launch a preemptive strike if they think we are about to deploy a working SDI system, and a violation of the ABM treaty. He also feels that even if it is installed, it will actually INCREASE the damage done in a nuke war. He reasons thus: Assume that a "best case" SDI system can get 50% of the incoming missiles. For the Russians, this is a "worst case", and military planners always try to allow for the worst case. Thus, the Russians will double the number of missiles shot at the U.S. in order to maintain the same damage. If we stop less than 50% (likely case), then we wind up worse than before. I won't take up space by discussing the rest of what Dr. Bowman said, as much of it has already been discussed here. -- -ed falk, sun microsystems ------------------------------ Date: Tuesday, 3 June 1986 10:56-EDT From: bcsaic!douglas at uw-june To: arms-d, RISKS@sri-csl Re: Basis for SDI Assumptions? I have to question two statements that were made by Bob Estell in relation to SDI software. The first one, "A missile defense is worth having if it is good enough to save only 5% of the USA population in an all-out nuclear attack" is oft-heard. The phrase "worth having" could be applied to a number of things that aren't being had by many people (things like food, shelter, medical care, or safer cars). The question of whether something is "worth having" irrespective of costs, as if one could snap his fingers and have that thing is fine for idle conversation but of little use realistically. The question of what is worth pursuing and to what degree must be taken up by society at large. The magnitude of SDI costs as well as admitted technical dubiousness must be compared with alternatives. We can't have everything that anybody says is "worth having." The second quote, "That shield might save 75% of the population in a terrorist attack, launched by an irresponsible source" deserves some comment. The "terrorist" argument is used fairly often also to garner support for SDI, as terrorism is a popular topic on television, etc. I am prompted to ask from what quarter this terrorist attack would arise. England? France? Also, I would expect that SDI would fail miserably in the event of anything less than the full-scale attack that it was billed as deflecting. How does this apply to Risks? The rationale and the requirements are the basis for a system. If these are invalid, the system will probably be invalid. As Herb Lin said, "Politics are just requirements at the top level." POSTING NUMBER 2: [Re Bob Estell's posting] I am not sure of the facts on this but I think it is pertinent to RISKS. What is the story on the software for the Sargent York gun? Was a "high level" language used. If so, and the complexity still defeated the project, it bodes ill for SDI which consists of [the logical equivalent of?] thousands (hundreds?) of Sargent York guns launched into space. If a high-level language was used, there is still life in the "historical" argument described by Bob Estell. ** MY VIEWS MAY NOT BE IDENTICAL TO THOSE OF THE BOEING COMPANY ** Doug Schuler (206) 865-3228 {allegra,ihnp4,decvax}uw-beaver!uw-june!bcsaic!douglas bcsaic!douglas@uw-june.arpa [The use of a high-level programming language is only part of the problem. In many cases, deep flaws exist in the design, and the implementation makes things only a little bit worse. In those rare cases where the design is actually sound, the programming language -- whether high-level or low-level -- introduces the possibility of additional flaws, such as loss of encapsulation, lack of strong typing, lack of consistent exception handling, improper sequencing or atomic actions particularly in distributed systems, lack of adequate control transfers and domain changes, and so on. But such problems exist in ALL of the commonly used programming languages. PGN] ------------------------------ End of Arms-Discussion Digest *****************************