Arms Control Wonk

30 Responses to “A Serious Russian Space Proposal”

1. 

   Captain Ned | February 9, 2011

   Excuse my cynicism, but extending the Kellogg-Briand pact to space will be just as effective as its original enactment.
2. 

   Allen Thomson | February 9, 2011

   I downloaded the Russian version of the document and, in Oznobishchev’s part (Chapter 5), found this interesting passage, which I think goes to a major problem in discussions of ASATs: at least the US and likely other countries can’t actually say what their concerns are because of considerations of secrecy and classification. Anyway, I’d be interested if you could comment on the “contentious question.”

   My fairly free translation:

   “In the opinion of the Russian experts, the Code of Conduct should first of all define the objects in space systems which are subject to actions which would disrupt their functionality. Second, the methods and means of those actions should be defined and, finally, the types of weapons which could be introduced into space or used from Earth against spacecraft should be defined. The Russian proposals included detailed proposals for such definitions.

   “Such a formulation of the problem is completely justified. In any legally meaningful document there should be an initial definition of the subject of the agreement or of the scope of limitations. However, inasmuch as even the subject (scope) of the limitations is a contentious question, in the end the authors of the draft Code avoided even descriptive definitions of the subject of the agreement, emphasizing ‘rights’ and ‘responsibilities’ of space-capable countries.”

   Original:

   “По мнению российских экспертов, Кодекс поведения прежде всего должен определить объекты космических систем, воздействие на которые приводит к нарушению их работоспособности. Во-вторых, должны быть определены способы и средства воздействия и, наконец, виды (типы) оружия, которое может быть выведено в космос или применено с Земли против космических аппаратов. В российских предложениях были даны развернутые предложения по этим определениям.

   “Такая постановка вопроса вполне оправданна. В любом юридически значимом документе вначале должен быть определен предмет договоренности или сформулировано определение области ограничений. Однако, поскольку даже предмет (область) ограничений является спорным вопросом, в конечном счете авторы данного проекта Кодекса ушли от каких-либо даже описательных определений предмета договоренности, сделав упор на «правах» и «ответственности» стран, обладающих космическим потенциалом.”
3. 

   Mark Gubrud | February 9, 2011

   Arbatov proposes to trade a ban on ground-based ASAT tests for a ban on space-based BMD tests. I’m not sure what makes this particularly realistic, although there is a lot more realism in this paper and others in the same volume than there is in many piles of American papers on space weapons and space security.

   A (test) ban on space-based BMD is a non-starter for the US as long as there are no American political forces (even among professional arms control advocates) calling for America to give up this foolish and dangerous pipe dream once and for all and to agree to do so under a binding treaty regime.

   In fact, the space warriors (the smarter ones, anyway) are even more opposed to restrictions on ASATs, despite the strong argument that the US has most to lose in space. So even that side of the deal needs a lot more work on our side of the table.

   But what makes Arbatov’s proposal really nonsensical is that, as you point out, ground based BMD tests can “serve as surrogates for ASAT testing, thereby defeating the purpose of a test ban.”

   Here I want to point out that even saying BMD tests are “surrogates” maintains the pretense that there is some meaningful distinction between a weapon that can intercept an ICBM warhead (when unprotected by simple countermeasures) at 300-1000 km altitude and 5-15 km/s relative (closing) velocity, and one that can intercept a satellite in the same altitude and closing velocity range. In reality, tests that establish that a given weapon system has the former capability establish that it has the latter with complete certainty.

   If a gun can kill an elephant, you may call it an “elephant gun,” but you know it can kill a rhinoceros, too.

   In order for a test ban to be effective in providing a meaningful security guarantee it must ban not only “ASAT” tests against “orbital” targets but also “BMD” tests against “suborbital” targets as well.

   You may say this is a non-starter for the US, but only because US policy is held hostage by an insanity which denies the well-established fact that midcourse BMD against long-range missiles, particularly with WMD warheads, is easily defeated by simple countermeasures and is strategically useless.

   What needs to happen is that the people who know and understand all this need to start saying so out loud and in the face of those who continue to deny it.

   A possible compromise would be to limit BMD tests to low altitudes and velocities, effectively limiting the BMD to short-range and theatre missile defense and boost- and terminal-phase intercepts. Although it would be better to abandon BMD altogether, such a compromise would allow a KE test ban that was at least somewhat meaningful while not allowing those forms of missile defense which can have at least some level of effectiveness (where WMD are not involved). For example, it might allow the SM-3 Block IA and IB versions, while not allowing the GMD or the SM-3 Block IIA and IIB versions.

   That would be arms control.
   • 

     Mark Gubrud | February 9, 2011

     Oops, that should have read:

     …such a compromise would allow a KE test ban that was at least somewhat meaningful while not prohibiting those forms of missile defense which can have at least some level of effectiveness (where WMD are not involved).
4. 

   Coyote | February 9, 2011

   Instead of all these obscenely nuanced arguments, why not propose a treaty banning all weapons that would create space debris? There is little short-term value to such attacks in war, but the long-term consequences of such strikes are well understood as being disastrous. Why is the arms control community dragging its feet in proposing such a ban?

   This would exclude ballistic missile defenses, since neither the attacking missile nor the defensive weapon achieve orbital injection speeds. The result of such an impact would not leave a debris field in space, but would stop an nuclear strike on a targeted spot on Earth.

   Is the the arms control community holding out in the hopes of banning all space weapons in one swoop?

   Cheers!

   Coyote
   • 

     Mark Gubrud | February 10, 2011

     One answer to your question, Coyote, is that it is like proposing a ban on rhinoceros guns. Nobody would ever dream of shooting a rhino with an elephant gun, would they?

     A ban on debris-creating ASATs only, understood as a ban on KE-ASATs, while allowing unrestricted development, testing and deployment of KE-BMD, would achieve exactly nothing as arms control, in view of the fact that current US plans call for deploying hundreds of ASAT-capable KE interceptors deployed in numerous locations around the globe and on highly mobile ships.

     What is worse is that a ban on debris-creating ASATs only would be taken as implicit license for non-debris creating weapons for interference with satellites.

     A further question, which is not in principle unanswerable but does point to the fact that your proposal is not as simple as it sounds, is What is the definition of “debris”? How about ground-based high power lasers that don’t shatter the satellite into 10,000 pieces but do render it inoperable, leaving one large inert piece of debris in orbit waiting to collide with another one? Or robotic parasitic ASATs that by deorienting a satellite achieve essentially the same effect? What about low-speed collisions? Some people like to argue that weather satellites could be maneuvered to collide with other satellites. Why doesn’t your idea run into the same issues?
   • 

     Amy | February 10, 2011

     Prof. Coyote says: “The result of such an impact would not leave a debris field in space, but would stop an nuclear strike on a targeted spot on Earth. ”

     This is untrue, based on empirical data.

     The success rate of BMD against incoming warheads with decoys and countermeasures, is exactly 0%.

     Mark has it right: BMD against nuclear tipped missiles is useless and unworkable.

     There are number of published arguments to this effect, as well as the GAO and test data itself.

     Kindly stop wasting taxpayer money.
   • 

     George William Herbert | February 10, 2011

     The result of a skin-skin head-on impact in space is not just two clouds of debris that settle gently on the original warhead and interceptor trajectories, back to earth. You get an explosion and two debris clouds concentrated on those trajectories, but with cloud expansion at up to kms/sec more than the vehicle original velocities in all directions (though expansion is higher in the direction of the vector of the other impactor).

     There’s probably little debris left in stable orbits after such an impact, but if the threshold is none, you can’t meet that. This would effectively as you propose it ban kinetic kill BMD.
   • 

     Jack Pirate | February 11, 2011

     As Mark said:

     Here I want to point out that even saying BMD tests are “surrogates” maintains the pretense that there is some meaningful distinction between a weapon that can intercept an ICBM warhead (when unprotected by simple countermeasures) at 300-1000 km altitude and 5-15 km/s relative (closing) velocity, and one that can intercept a satellite in the same altitude and closing velocity range. In reality, tests that establish that a given weapon system has the former capability establish that it has the latter with complete certainty.
   • 

     John Schilling | February 11, 2011

     The claim that “there is no value to such attacks in time of war”, is one you are going to have to defend rather than simply asserting. Anybody who is on the wrong end of a JDAM, has their life expectancy substantially increased if they have a button they can press to turn the entire GPS constellation into orbital debris. If it’s a Predator-launched Hellfire with your name on it, you might want to take out a few comsats instead, but same principle.

     That adds up to a pretty substantial list of people, and possibly entire regimes, that would stand to gain the short-term benefit of Not Dying Right Now by carrying out such attacks.

     And the flip side of that is, if the threat is posed by coorbital ASATs, there’s another long list of people who would derive a short-term benefit from preemptively fragmenting the ASATs at the onset of hostilities.

     There is real military advantage to being able to make other people’s satellites not work any more, which task is most reliably accomplished in ways that happen to turn them into debris. That this would in the long run be a negative outcome for the world as a whole is largely irrelevant; decisions on whether or not to use a particular weapon are dominated by the local, short-term costs and benefits.

     And, historically, arms-control proposals that involve an outright ban on types of weapons that offer a real military advantage to those who use them, have a very low success rate. I think most of the arms control community would prefer to focus on proposals that have a realistic possibility of success.
   • 

     Mark Gubrud | February 13, 2011

     George,

     Transverse velocities acquired by the bulk of cataloged debris from the FY-1C intercept were less than 200 m/s. This tells you that even at low altitudes an impact of an orbital target will produce a large fraction of persistent debris.

     However, I take your point to be about impact on a ballistic missile. This is an interesting question for more detailed quantitative analysis, but given that some of the cataloged debris from FY-1C had acquired transverse velocities as high at 0.5 km/s and the tail of the distribution for light pieces might extend higher, I would say you are probably right that a zero-debris criterion would ban KE intercept of ICBM targets at apogee, i.e. would ban the very type of midcourse BMD that we already know is easily defeated by simple countermeasures.

     However, zero-debris probably would not ban boost- or terminal-phase intercepts or apogee intercepts of short-range missiles.

     Once again, a reasonable compromise between banning ASATs and not banning forms of BMD that have at least some limited military utility would be to impose an altitude/burnout velocity limit which could reasonably be engineered to allow SM-3 Block I A/B which ruling out SM-3 Block II and requiring the retirement of GMD. The latter weapons do not and cannot provide us any real protection against ICBMs, but would constitute a major KE-ASAT threat that the Chinese and others would match.

     John,

     You do not explain what kind of button anyone could press which would cause the entire GPS constellation to be turned into orbital debris. Nor do you explain how the coorbital ASATs (which presumably are known, both to exist and their actual whereabouts) are to be promptly fragmented at the onset of hostilities.

     You are not talking about the kinds of antisatellite weapons that are easy to do, easy to conceal, and hard to ban, but easy to defend against. You are talking about things that are hard to do, hard to conceal, and hard to defend against but not so hard to verifiably control.

     I don’t think there has ever been a class of weapon that has been banned that somebody hasn’t argued could “offer a real military advantage to those who use them”. I think it is fair to ask what is the real military advantage in strategic war between nuclear-armed states. Or in trying to secretly break out of an arms control regime to prepare and execute, before being detected, what would be the first strike in such a war — at the risk of chaos if such a plan should fail.

     I also think it is fair to ask what the implications are for global and human security, a few decades from now, if we fail to prevent a space arms race.

     For these reasons, I do believe that a serious and comprehensive approach to space arms control has a very realistic possibility of success.

     Mark
5. 

   Andrew Tubbiolo | February 10, 2011

   What does this mean?

   “provocative deployment of destabilizing surveillance and reconnaissance systems in space…”

   I wonder if SPOT would have fallen under that definition in April 1986? Regulating going out and having a look about comes across as rather stark. How to do you treat nations the way nations treat enterprises like Ikonos?
   • 

     Allen Thomson | February 13, 2011

     It would be interesting to see examples of “surveillance and reconnaissance systems in space” that are provocative or destabilizing, and a separate list of ones that aren’t.

     On which list would fall, for example, Ofeq, Helios, IGS, “Lacrosse”, “Crystal”, NOSS, Woldview, GeoEye-1, various Yaogan Weixing, etc.

     BTW, I agree with John Schilling’s post of Feb 11 and believe that the considerations he points out will prevent any comprehensive ASAT ban from getting to the negotiating table, let alone being signed, let alone being honored in time of war. Better to try to come up with a more modest agreement that would limit the more widespread pernicious effects of ASAT and have some chance of being effective.
6. 

   Anon | February 10, 2011

   Coyote, Why midcourse missile defense will not work:

   http://www.youtube.com/watch?v=67KAsQkIzsY
   • 

     Coyote | February 13, 2011

     Anon,

     The Union of Concerned Scientists has a political agenda, but no insight into the missile defines program. They are not a credible source on such matters.

     Cheers!

     Coyote
   • 

     Anon | February 13, 2011

     How about you respond to the content of the video instead of spewing ad hominems?

     What precisely is wrong in what is shown? I would love to know.

     I think you or your friends have or had material or political interests in missile defense, so I tend to doubt whatever you say.
7. 

   Thomas | February 10, 2011

   In addition to kinetic ASAT weapons, we should also be thinking about ground-based lasers. The Chinese (and I assume the Russians and the US) have in the past demonstrated the ability to fire sustained beams on satellites in LEO (and also MEO?). With low energy lasers, one can damage or destroy an imaging satellite’s optics and sensors; with high power one could just slag the whole thing.
   • 

     Anon | February 13, 2011

     Yes, the US leads in this ability.
8. 

   Coyote | February 13, 2011

   Mark: Focus on behaviors and not the weapons. It will be easy for the international community to discriminate a kinetic attack on a satellite from a missile in flight. Punish an offender for debris creation—but remain sensitive to the inherent right of self defense, which cannot be voided.

   Amy: Missile defense tests are incredibly public events that are observed by foreign intelligence collectors. Because of this, the full spreads of pen-aids, countermeasures (CMs), and counter-countermeasures (CCMs) are never employed on such tests in order to preserve secrecy. Such systems are tested elsewhere. We would, in fact, be wasting money if we did such tests in view to the public.

   George: Yes, in some cases an explosive impact between a missile and an interceptor may send minute fragments into an orbital injection… which is one reason why explosive impacts are avoided. Instead, the endgame at impact usually involves the interceptor shooting non-explosive “bird shot,” if you will, at the target missile. This prevents injecting debris.

   John: You raise some interesting questions. One of the reasons why there is no incentive to develop kinetic destruction weapons to strike satellites is because such weapons are tremendously expensive when cheaper and equally effective jammers, lasers, and other directed energy weapons can do the job at a fraction of the cost. As Ambassador Schulte pointed out recently, even Ethiopia has an active satellite jamming program. There is no denying that countries have the inherent right of self-defense, and that this may extend to the space segments in the so-called kill chain. However, there is a deterrence against such attacks on the space segment. If GPS is negated, or if the communications links on precision fire control systems are likewise negated, the result will be less precision in the prosecution of attacks. In other words, more weapons will be expended on targets to achieve the necessary probability of kill (PK) with less ability to control the collateral damage. So, attacking precision services will result in greater brut force against ones self.
   • 

     Amy | February 13, 2011

     Coyote: “Because of this, the full spreads of pen-aids, countermeasures (CMs), and counter-countermeasures (CCMs) are never employed on such tests in order to preserve secrecy. Such systems are tested elsewhere. ”

     Thus they will never be tested realistically.

     Also, you do not know a priori what penaids NK plans to use. So you can use whatever supersecret crap you wish, it does not reflect what will be used against you.

     Further, in the bloody tests where you DO use penaids visible to the whole world — even then the success rate in 0%.

     Unless you are saying that MDA lies that they used countermeasures in FTG 06 and FTG 06a. And neither test worked.

     Are you saying MDA are liars? I mean we have ample proof already but it would be helpful if you weighed in.
   • 

     Mark Gubrud | February 13, 2011

     “Focus on behaviors and not the weapons.”

     Then there is no need for arms control at all, we can just agree never to have a war, right? But wait, behavior changes in crisis and war, doesn’t it?

     “Missile defense tests are incredibly public events…. the full spreads of pen-aids, countermeasures (CMs), and counter-countermeasures (CCMs) are never employed on such tests in order to preserve secrecy. Such systems are tested elsewhere.”

     I see you’ve been working on this argument. But it still boils down to, “Trust us,” against all evidence. And it doesn’t make any sense. How can you possibly test these “counter-countermeasures” if you don’t test them as part of the missile defense? Why are we supposed to believe that they will work? Or even that they exist, when nobody can suggest a plausible solution to the well-known mylar balloon shell game? And why does MDA conduct these “cheap magician’s tricks,” flying mylar balloons whose signatures are known and markedly different from the known signature of the test target warhead, and testing the onboard discrimination capabilities of the interceptors against these fake countermeasures? Why don’t they just tell us what you’re telling us? I thought you were all on the same team.

     “the endgame at impact usually involves the interceptor shooting non-explosive “bird shot,” if you will, at the target missile.”

     Which interceptor is that? Not SM-3, not GMD, not THAAD, not PAC-3.
   • 

     Amy | February 13, 2011

     Coyote: “usually involves the interceptor shooting non-explosive “bird shot,” if you will, at the target missile. ”

     Really?

     So MDA is lying to us and you just let out a classified state secret?

     Who do we believe: you or MDA?

     News story here I would say.
   • 

     George William Herbert | February 14, 2011

     They’re not using “non-explosive birdshot”, they’re doing skin-to-skin impact.

     And you miss the point entirely. Impact kinetic energy is explosive in these velocity ranges. KE = 1/2 M V^2. A 3,000 m/s impact has 4.5 million joules per kilogram, which is more energy than TNT (4.2 Mj/kg). A 6 km/s impact will have 4 times more energy than an equivalent mass of TNT. Merely lofting a brick straight up so that it reaches apogee at the same time as a passing LEO satellite will give you 7,200 m/s impact velocity. Most ABM systems fly a head-on trajectory and give you even higher impact speeds.

     ICBMs are marginally slower than LEO velocity, but it’s still in the 6 km/s range typically, plus whatever the interceptor vector is (which is probably similar, and probably in about the exact opposite direction).

     That there’s no explosive involved doesn’t matter – when you hit something that fast, due to the energy involved the impacting parts explode immediately on contact.
   • 

     Mark Gubrud | February 15, 2011

     George, your discussion is correct, but a bit confusing, since a collision that is head-on in the Earth frame can only be arranged if the interceptor is launched from the missile aimpoint, therefore most intercepts will be at some angle in the Earth frame.

     This doesn’t matter much, since a 90-degree intercept (Earth frame) will still occur at the full speed (Earth frame) of the missile, and in fact even a tailchase at a small angle (Earth frame), or an intercept in which the missile “catches up” with the interceptor, will usually destroy the warhead if the warhead itself is struck.

     More fundamentally, what the intercept looks like in the Earth frame is irrelevant. In the frame of the missile or of the interceptor, or of their center of mass, you just have two objects approaching each other at some high speed. In that sense, all collisions are “head-on.” However, in most engagements, the missile will be struck on its side, and that is preferred since it gives a larger target area.

     The range of intercept geometries is generally the same when the target is a satellite, which is why there is no meaningful distinction between KE-BMD and KE-ASAT. BTW, the Obama administration has just decided to transfer $1.7 Bn from “efficiency savings” in the DoD budget to accelerate development and deployment of the SM-3 IIB kinetic energy ASAT (aka missile defense).
9. 

   Coyote | February 14, 2011

   Amy, Mark, and Anon,

   The missile defense program is neither a conspiracy, nor a deception. It represents a series of decisions made by presidents, senators, and representatives of both political parties over several decades. It is one of the rare programs that enjoys long-standing bipartisan support across multiple administrations. It is not a matter of “trust us,” rather it is a matter of trusting your representatives and President who oversee the Missile Defense Program—each with their own independent scientific and technical advisers. You have the right to vote and to lobby to make your voice heard in the political system.

   That said, the Missile Defense Agency (MDA) undergoes tremendous scrutiny; inspections, investigations, studies, review panels, and inquiries, inter alia. I support the findings of reports that indicate that greater efficiencies in management and budgeting are possible, desirable, and mandated. Ironically, so much oversight is driving up the cost of the program, but it is not an insurmountable problem.

   The MDA deals with considerable technologies and operational methodologies that require management under a rigorous classification system established by executive order. It is fair to debate whether too much is classified, or too little, but for now, the President, the Director of National Intelligence, and those who provide oversight, have decided that most of the information related to missile defenses must be protected. By law, it is their call, and we do appreciate living under the rule of law. So, don’t be offended that MDA cannot tell the whole story to the public (nor display it in a single test flight), but only releases the unclassified bits. The whole story—the good, the bad, and the ugly—is fully disclosed to inspectors and those in political positions among both parties who provide continuous and aggressive oversight.

   The public descriptions of the overall missile defense architectures that are presented to the public—as used by the Union of Concerned Scientists—are vague, general ideas that do not provide sufficient detail to understand what is actually going on. Uninformed analysis immediately goes astray with false assumptions, and yes, given such little information it is reasonable to draw assumptions that missile defenses will not work. It doesn’t matter what the professional pedigree of the person doing the analysis is, when they lack most information about a subject, their conclusions and recommendations are usually wrong and misleading.

   But that’s the way it is supposed to work. We’re not in the business of doing the foreign intelligence analysts’ jobs for them. In fact, we try to entice them into drawing wrong and misleading assessments and recommendations, too. Work by the Union of Concerned Scientists (UCS) and other such analysis think tanks can be quite helpful, because in many cases, they communicate back to us what logical deductions can be drawn from the public message. However, in my opinion, the position of the UCS on missile defense has been overly strident given the limitations of their evidentiary base. In this case, their political agenda speaks louder than their critical analysis.

   So, don’t expect to be given a public demonstration of a missile defense test that shows the full spread of sensors, CMs, or CCMs. Such systems go through complete testing regimes of their own. Surrogate testing is prolific. As an example—although entirely contrived—every time we perform orbital rendezvous at the ISS we learn how to put two objects together in space. We can even use different sensors for acquisition, tracking, and endgame contact that can focus on different shapes or devices on the ISS itself. Perhaps this has relevance to missile defense sensors, CMs, or CCMs and their operation? I don’t know, but maybe it does. Given the incredible speeds of computers these days, it is not a far-fetched extrapolation to condense the drawn-out experience of docking with the much accelerated experience of missile interception. The result could be flight-tested hardware and software that is ready for prime time.

   Sorry to disappoint, but no classified state secrets coming from me. All of this stuff is out there. As for the endgame interceptor using non-explosive birdshot for interception, just look at how we design such weapons for air-to-air interception. The missile gets just so close to the target aircraft and WHAM! It spalls-off thousands of pellets, like birdshot, in the direction of the target. The result is a higher probability of kill even with the deployment of countermeasures. If you really want to learn a great deal about missile defense, a thorough study of air-to-air missiles would be a fabulous place to start.

   The bottom line is that the Obama administration has full control of the Missile Defense Agency. They are careful, thoughtful, and practical.

   Be of good cheer!

   Coyote
   • 

     Amy | February 14, 2011

     Thank you as you exploit the synergies between my pocket and Raytheon.

     You can usually judge the Bovine Scatological content of debaters by how they try to obfuscate via length and MBA terminologies.

     The bottom line is still this: In empirical tests of the system it has 0% success rate against countermeasures. And these are countermeasures whose signatures the intercept team knows ahead of time and where the intercept team knows all the parameters of the incoming missile as well as its exact launch time.

     Thus Coyote and MDA are spewing bunk to the American taxpayer. As they have for decades while spending our $.
   • 

     Mark Gubrud | February 14, 2011

     Those are a lot of nicely-written words, Coyote, with little content that commits you on any substantive, let alone verifiable point.

     Just to be clear, do you claim to be in the know with “sufficient detail to understand what is actually going on”? Or are you being paid out of the public treasury to wage political warfare on behalf of programs that are as opaque to you as you claim they are to us?

     You say you “don’t know” whether information gained in ISS docking maneuvers can be used in missile defense. I believe you.

     You say we should imagine how air interceptors use explosive/fragmenting warheads. Well, we can imagine that. But all publicly available information, including photo images and drawings of the missiles and their kill vehicles, supports the fact that SM-3, GMD, THAAD, and PAC-3 all use direct hit-to-kill warheads, which makes sense if you assume (as MDA appears to) that the precise aimpoint can be identified, since simple missiles generally will not rapidly and unpredictably maneuver to evade interception as aerodynamic vehicles easily can. (Of course, missiles could be equipped with thrusters for evasive maneuvers in space, which is another kind of countermeasure.)

     Given the poor success rate of MDA’s tests without “the full spread of sensors, CMs, or CCMs”, it is pretty hard to have faith in the kind of missile defense system whose visage you are conjuring out of vapor and suggestion, i.e. one which, by your description, has never been tested (I mean, really, actually tested) at all.
10. 

    Mark Gubrud | February 14, 2011

    Followup: Some sources do report that Pac-3 uses a “lethality enhancer” blast/fragmentation warhead, but MDA, LockMart and Boeing all state that it is hit-to-kill with radar terminal guidance; LockMart also explains that “explosively fired” pulse rockets are used in terminal homing, which suggests that the Pac-3 warhead would like to have got rid of all excess mass, i.e. separated from its booster shells and not be carrying a reported 73 kg frag warhead as it tries to home on the incoming missile. In any case, with a ceiling of 15 km, Pac-3 is not quite exoatmospheric; it may designed for dual roles against aerodynamic and ballistic threats.

    The use of fragmentation of “birdshot” is not a solution to the decoy discrimination problem since the “threat cloud” consisting of many decoy balloons and one with a warhead inside will be dispersed over too large an area for fragmentation to be an effective strategy. The “lethality enhancer” on Pac-3, if it is present, would serve only to relax the requirement from hit-to-kill to near-miss of a target that still has to be correctly identified and homed in on.

    Note that at 15 km the balloon decoy countermeasure does not apply, but now we are talking about terminal phase intercept where the interceptor has to be based very close to the defended target, or conversely has a very limited footprint which it can defend. This kind of BMD is of some limited military utility in that it can reduce the number of conventionally-armed missiles that make it to (usually military) targets within the defended area. However, its effectiveness is only fractional, which means it is of no utility in defending population centers against WMD. One nuclear weapon can ruin your whole war.
    • 

      yousaf | February 15, 2011

      “One nuclear weapon can ruin your whole war.”

      Indeed. Something Pavel and I have written on:

      http://www.foreignpolicy.com/articles/2009/10/21/what_missile_defense?page=full

      http://www.thebulletin.org/web-edition/columnists/pavel-podvig/the-false-promise-of-missile-defense