As I understand it, missile defense systems have not been particularly successful. But, as I understand it, these systems mostly work by trying to hit incoming missiles with outgoing ones.
This sounds like trying to kill a fly by grabbing a blow dart instead of a fly swatter.
Have other techniques been tested that use nets, shrapnel, etc. to create a wide mass that disrupts the incoming missiles?
AIUI, the Patriot doesn’t actually try to hit the inbound missile; when it gets close, a proximity fuze detonates the warhead, which propels a rain of fragments. So it may be more accurate to think of the Patriot as an airborne shotgun of sorts rather than a blow dart.
Likewise with Israel’s Iron Dome system.
There are two types of technologies that are used for missile defense, hit-to-kill and those that use an explosive warhead. Each has had good days a bad, to put it mildly.
The Patriot missile system used in the 1991 Gulf War included an explosive warhead, and despite early press claiming how successful it was against Scud missiles (with hundreds of miles of range), it actually wasn’t. It probably hit several incoming warheads, while other incoming warheads simply disintegrated due to poor design.
On the other hand, the Iron Dome missile system, now in use by Israel to defeat small rockets with ranges of dozens of kilometers, seems to have done quite well with its explosive warhead.
The newest Patriot missile, which has been fielded for oh, call it ten years or so now (not sure off the top of my head) is a hit-to-kill missile. It works both on incoming missiles and against aircraft (though not quite as well against aircraft).
For intercontinental ballistic missiles, the US has had decidedly poor test results. However, even if the kill vehicle on the currently-deployed system were changed to have a warhead, that would NOT have any advantage. The main challenge with the current system is that it has a lot of moving pieces: the sensors must be quite accurate, the anti-missile missile has a huge amount of energy, the kill vehicle must maneuver quickly and efficiently, and it is possible for an adversary to throw up chaff and debris to try to confuse the system. Not to be too optimistic about it, but the least of the problems of the current system happens in the last second of the intercept. It’s everything that happens in the ten minutes before that is the challenge.
For what it is worth, the last couple tests on the US’s national missile defense system have been promising, with the caveat that the whole program has moved back to a “crawl-walk-run” strategy, instead of trying (and failing) to achieve realistic scenarios that were the basis of tests for quite some time. There’s a big realistic test scheduled for late this year, the first realistic test in quite some time.
And I can’t go without saying that in the 1970s, both the US and the Soviets were permitted by treaty to set up two anti-missile sites in each of their countries. The basis of these missiles was to detonate a nuclear warhead in space to destroy missiles headed for Washington or Moscow. The US scrapped this program, but it remained operational in the USSR/Russia for a surprising amount of time.
When the anti-missile sites were permitted (2 each for US and USSR,) the Soviets chose to build an anti-missile system around Moscow, while the US decided that maintaining a counterforce ICBM group was more important, and constructed Safeguard sites in North Dakota and a (never completed) site in Montana. A third site in Missouri was scrapped even before the ABM Treaty was signed in 1972.
That’s right, thanks for the correction. I blame poor memory for my mistake.
Yeah, about that,Ted Postol disagrees with that.
“Seems.” One can never quite tell if Ted Postol is a genius or insane.
I’d say the memory’s pretty good, though! Not many people remember that the Safeguard and A-135 ABM systems existed. (actually I guess the A-135 still exists)
One thing about those is that they’re often intending to intercept the warheads in the upper atmosphere, so they’re likely still protected by whatever heat shields they have. So shrapnel might not be nearly as effective as you might think.
Plus to a large degree, guiding the kill vehicle close enough for a reasonably sized warhead to destroy an incoming RV with fragments is probably just as hard as simply hitting it outright. And the hit-to-kill method is more “sure”- no RV is going to withstand that.
Your fly swatter analogy is quite apt. It’s much easier to swat a stationary fly before it takes flight rather than in mid-air. The same is true of missiles. The most effective anti-missile system would be one that destroys the enemy missile before it is launched. Of course, if you build such a system, it could also work amazingly well on airplanes before they take off, or even on cars being driven by generals who have not yet given the order to attack. But it would be an awful example of doublespeak to call such a system “defense”.
The original Patriot missile, originally designed mainly to engage air breathing targets, has a radar proximity fuze. Upgraded versions of the system use upgraded versions of this missile to engaged ballistic missiles. This was the case with so called PAC-1 and PAC-2 upgrades used in the 1991 Gulf War against Iraqi medium range BM’s with debatable results. However the so called PAC-3 system uses a completely different missile purpose designed to intercept ballistic missiles using ‘hit to kill’. It’s confusing because the missiles are only differentiated by a letter version, MIM-104B, C and D are the original missile with various upgrades to engage BM’s, MIM-104F is a totally different missile. The Patriot system as a whole (radar, fire control etc) is a gradual evolution and not completely different in the -3 iteration, the latest systems can fire either type of missile (the MIM-104F is much smaller, four of them fit into the same space as one launch canister of the older missile).
As Ravenman said, there are two general types of ABM warhead. HE/fragmentation with proximity fuze and hit to kill. However as also mentioned ABM’s designed to intercept very fast (ie very long range) BM’s and deployed ca. 1970’s (especially by USSR, the single US Safeguard site completed was fully operational for less than a year in 1975-76) used nuclear warheads.
The limit to a proximity fuze/HE arrangement is closing speed. The longer the range of a ‘pure’ BM, the faster it’s going on its downward trajectory. At certain closing speed it becomes impractical to time the functioning of the fuze and warhead accurately and repeatably enough. Also consider that outside the atmosphere there is no blast pressure wave to use against the target, just the fragments of the warhead’s casing. Regular ground launched antiaircraft missiles with HE/proximity fuze had some capability against relatively slower battlefield tactical BM’s even way back: the HAWK system was successfully tested against a Corporal battlefield nuclear missile (~75 mile range) back in 1960. But for very fast BM targets in those days a nuclear warhead was necessary.
In more recent times advances in guidance electronics made hit to kill feasible for very high speed BM’s (and it’s sometimes even chosen for slower targets, including a/c, because the intercept missile can be smaller). However as is well known, it is still very challenging to get these systems to work, back to front, in a fully reliable way.
Also note that ‘hit to kill’ warheads which operate outside the atmosphere often have an umbrella like device that makes them much bigger than the missile’s diameter, though nothing like as big as the radius of effective fragmentation of an HE/frag warhead.
I recall that. The military said it wasn’t right for the job, there was hype in the press about how effective the Patriot was and when it came out that it wasn’t doing so good after all lots of people blamed the military and conveniently forgot they’d said it was a bad idea from the start.
As I recall a major problem was that that version of the Patriot was designed for defending relatively small targets (like a military base) against precisely targeted missiles; as such, it had a small warhead that was designed to do just enough damage to make the missile miss the target. Not to outright destroy the incoming missile.
The Scuds on the other hand were horribly* inaccurate *missiles being aimed at a very large target, a city; as such they were one of the worst possible things to use that model of Patriot against. If the Patriot managed to knock it off course it generally wouldn’t matter since it wasn’t aimed very precisely in the first place. The Scud just hit in a different random spot than the other random spot it would have otherwise landed on.
Dr. Postol certainly has an axe to grind but for readers who are familiar with the systems and tests which he critiques it is difficult to substantially disagree with his assessment. Some of his detractors argue that he is not an ‘expert’ on missile defense systems and therefore his arguments are uninformed, but in fact he has worked in the ICBM world (on basing methods and survivability assessments for the MX/Peacekeeper system) and clearly has sufficient knowledge to make credible evalutions of the value and purpored success of testing.
There are actually three phases of interception: boost phase while the boost vehicle is still operating, prior to the release of the post-boost vehicle (PBV), mid-course phase while the PBV is targetting and adjusting, and then after RV release around apogee, and the terminal phase where the RVs on their purely ballistic path from apogee to reentry and then to the detontion altitude. The surest kill is during boost, because it will prevent the RVs from achieving the desired throw range and reaching the target; however, it also means an interceptor has to be somewhere close to the downrange ground track and a threat discrimination and intercept order has to be made within a few tens of seconds of launch, essentially requiring automated response and the attendant risks. Mid-course is generally considered the best balance of surety and feasibility, especially if it can be done before RV separation, or against a unitary (non-separating) target. However, it requires a long range boost vehicle (basically an MRBM-class vehicle) and has a number of challenges with target tracking and terminal interception as it is usually well over the horizon from precise target tracking systems. (The notoriously unusable Sea-Based X-Band radar was to provide this capability for the US Ground-Based Mid-Course Defense ABM system, but has never functioned with anything like operational capability and has spent most of its life to date sitting at Pearl Harbor doing exactly jack shit.) Terminal phase interception is really only suitable for point defense of facilities and is a major technical challenge in terms of assuring interception, both because of difficulties in precise tracking and the lack of time for followup interception, essentially requiring mulitple interceptors for high assurance of target termination.
The thermal protection systems on the RV will do little or nothing to protect the vehicle from interception, and in fact, there is no physical shield that could absorb that kind of momentum even in a purely kinetic mode. However, it should be noted that thermal protection systems on a boost vehicle, e.g. the cork or rubber sheathing that protects the motor body or airframe from aerodynamic heating will also protect against directed energy weapons such as the now cancelled Air-Borne Laser, and as such are an almost trivial effective countermeasure. Other countermeasures are to deploy decoys and radar-reflecting chaff by the PBV to prevent accurate threat tracking and discrimination. The problem with fragmenting interceptors is that the frag field still has to be quite dense to assure interception. Although direct hit-to-kill (HTK) intercpetion is technically challenging, it has been demonstrated repeatedly. The bigger problems are discrimination, terminal tracking, and coping with countermeasures.
The SCUD missiles that were deployed and launched by Iraq in the First Gulf War were also modified for extended range without testing or good analysis, and are widely thought to be unstable in terminal flight. Whether or not you believe the PAC-1 missile system was effective or not, the threat vehicles were unlikely to reach their intended targets.
The biggest cockup about missile defense is that we now have several systems which are operationally deployed with very limited and highly orchastrated testing designed to ‘demonstrate’ success under supposedly nominal threat conditions rather than stress the system to see where it is weakest. It is fortunate that most of the threats against which it might be employed are at a similar state of substantial unreliability.
Stranger
I’ve always been irritated about the Patriot thing. Some source will say it’s the best thing ever and it never fails, and others will say it’s a total fraud and never took out a single SCUD. It’s the kind of all-or-nothing thinking you’d expect from people who are not serious scholars and have not actually done their research.
FWIW, I’ve spoken to people who were in Desert Storm and they claimed to have seen Patriots destroy incoming SCUDs first-hand. One guy I met was certain that he would be dead if it hadn’t been for the Patriot protecting his base. Maybe he was right, or wrong, but it seems to me that the Patriots worked at least some of the time.
It might be noted that there’s a similar though less extreme debate about Israeli Iron Dome combat performance. The Israeli forces quote a very high success rate others have questioned.
Patriot had a less controversially successful record against Iraqi BM’s in the 2003 war, but those were shorter ranged hence slower targets than those in 1991. And the interceptors were so called PAC-2 GEM/GEM+ upgrades of the missile type used in 1991 and some PAC-3, which is totally different, hit to kill, missile fired from the same basic system see above.
Anyway the fact that one iteration of one particular system is successful or not does not prove anything about future performance. The interceptors can improve, so can the targets (decoys, maneuver, etc).
What do you think about his specific opinions on the Iron Dome’s purported performance (linked above)?
[QUOTE=Chihuahua]
FWIW, I’ve spoken to people who were in Desert Storm and they claimed to have seen Patriots destroy incoming SCUDs first-hand. One guy I met was certain that he would be dead if it hadn’t been for the Patriot protecting his base. Maybe he was right, or wrong, but it seems to me that the Patriots worked at least some of the time.
[/QUOTE]
Every since the invention of aircraft and then ground-based air defence, claims of kills have been several fold, higher than actual, even those made by serious military professionals trying to do nothing more than estimate enemy losses.
There is absolutely no way a single observer on the ground can assess whether an intercept attempt was successful or not. The PAC-2 has a fragmentation warhead so an observer will see it explode regardless of whether an intercept is successful or not. On the other hand, the Al-Hussein missile, which is a notionally unitary threat (the warhead does not separate) is well known to break up upon atmospheric reentry, and the PAC-2 software will tend to aim for the largest component, which would be the airframe rather than the RV.
The observer on the ground can only see the detonation of the interceptor warhead, which proceeds the intercept and creates a large stationary fireball, and may occur on either side of the trajectory without the observer being able to tell. Unless there is imagery taken from the near on-trajectory aspect (e.g. following the vehicle) it is pretty much impossible to determine whether the target was directly intercepted unless there are two observations from known locations that can be triangulated to calculate the likelihood of a successful intercept. The DoD assessments went from an initial claim of 96% down to less than 60%, while GOA and CRS assessments went down to 40%. Dr. Postol led a review board that evaluated the available objective data (ground and CAST GLANCE imagery) and estimated a maximum possible success rate of 10% and possibly 0 success out of 44 claimed intercepts.
Regardless of what your buddy thinks he saw or his faith in the capability of the Patriot, his anecdotal experience in no way validates claims of success, and an objective look at the as-tested capabilities and objective evidence of operational performance tends to indicate that the PAC-2 is not nearly as capable as the originally advertised capability (hence why it has been replaced by the PAC-3, which has much greater capabilities and has had a 100% test success so far), while the instability and inaccuracy of the Al-Hussein (modified Scud) missiles is well known.
I really have no idea about the performance of Iron Dome, but the criticisms that Postol presents are plausible. I don’t know how much operational test or in-field data exists to evaluate the hypothesis, and there is often a large degree of interpretation in using less-than-high fidelity in-field data (usually grainy visual spectrum video) but there is a substantial tendency by the manufacturer and the operator to overestimate success and effectiveness, both deliberately and unconsciously.
Major General Partridge: I’m not going to sit here and tell you the Paveway never missed.
Madame Chairwoman: It missed by a mean distance of five miles, and nearly fifty percent of the time.
Major General Partridge: You know, in baseball, a guy that hits .400 is considered pretty damned great.
Congressman #1: In baseball, the losing team isn’t killed by their opponents.
Stranger
From what I read on the article, the Israeli claim if true should show more wreckage on the ground than has been shown. Based on the article, it also would indicate that the Iron Dome system, is unable to use a forward hit kill due to the ballistic trajectories, and seems to be engaging in more tail chases.
He seems to believe that the 90% kill rate does not track with civillian casualties, when taken into account the Israeli civil defense measures. Or that the system is not 90%, but due to civil defense, what is getting through is not causing casualties.
What I don’t see, is evidence of higher property damage, if more of the missiles are getting through than indicated, absent the ones that simply fall on unoccupied ground, there should be more houses and buildings damaged, than what he is thinking.
Does Israeli insurance companies, or renovation companies provide any data for that.
Declan
n/m
Similar video analysis methods used on the Patriot PAC-2 have been used to evaluate Israel’s Iron Dome ABM system, and the same analyst claims that just like PAC-2, Iron Dome is only 5% effective. There is some good commentary in this article: http://aviationweek.com/blog/iron-dome-are-critics-target
However some of the Iron Dome videos look much better than 5% effective. In this video showing a massed attack and an apparent steep overhead descent, if most of the interceptions failed you would expect to see surface detonations all around. (Main part starts at about 00:25).