Scorpion wrote:Jeez guys, lighten up! I was honestly under the impression that US ABM efforts had been unsuccessful (due to some news articles I read back in the Bush years). So why the hostility? Can't a guy make an honest mistake without being beaten over the head because of it?
No one insulted you. You didn't get in a heated debate where you argue against the facts, showing everyone that you're a dumbass, or something like that.
When you make a honest mistake, you get called on it. That might include some beating with some facts. No harm done, and no one displayed any hostility to you in person.
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I was friendlier then I could be, but you know it is kind of annoying when people make ridiculous statements that could be checked up on in seconds.
"This cult of special forces is as sensible as to form a Royal Corps of Tree Climbers and say that no soldier who does not wear its green hat with a bunch of oak leaves stuck in it should be expected to climb a tree"
— Field Marshal William Slim 1956
On Lost our production offices were in the Dole Cannery complex, whose refrigerators were pressed into service for morgue purposes after the Pearl Harbor attacks (where civilian casualties were stowed). That was down on the third floor; the security guards like to claim that they 'still hear strange noises' coming from that floor, which had been disused for some time, by the time we moved in.
Even back in the late 1990s there were very impressive technical demonstrators out there. I spent some months working with Dave Scott of Gemini and Apollo fame, developing ideas for converting the USAF's AHIT hit-to-kill technology demos for a return-to-the-Moon project pitch (which was really a sort of stealthy let's-go-to-Mars concept).
I find myself endlessly fascinated by your career - Stark, in a fit of Nerd-Validation, November 3, 2011
Kanastrous wrote:Even back in the late 1990s there were very impressive technical demonstrators out there. I spent some months working with Dave Scott of Gemini and Apollo fame, developing ideas for converting the USAF's AHIT hit-to-kill technology demos for a return-to-the-Moon project pitch (which was really a sort of stealthy let's-go-to-Mars concept).
I think you may have mangled the program acronym, or that's some obscure program I've never heard of.
The US Army did have a HIT programme:
(LTV) HIT (Homing Intercept Technology)
It was developed in the very late 1960s/early 1970s to MIRV the Spartan ABM to provide a non-nuclear multi-target kill capability. The ABM treaty killed any practical implementation of HIT.
Aviation Week & Space Technology. May 6, 1974
The Army's Homing Intercept Technology (HIT) is now in its third stage and will be ground-tested in a chamber under contract with LTV Aerospace Corp. to determine if the small, lightweight (a few pounds) warhead can home on simulated targets and deploy its kill mechanism for point detonation.
Prior to the signing of the anti-ballistic missile treaty and interim offensive ICBM weapons agreement in May, 1972, the Army was developing the Homing Intercept Technology program for use as multiple independently-targetable interceptors.
The ABM treaty prohibits multiple interceptors in a single booster, even if the work is merely a feasibility study of the concept, according to a Pentagon official.
...
The Homing Intercept Technology program developments now under contract are not prohibited by the treaty and are continuing, a Pentagon official said. He added that the final phase originally planned, launching cluster warheads, has been canceled.
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Under the original concept, or if the treaty is abrogated by either party, a large number of the small warheads would be used on an improved Spartan interceptor and they would provide a "cumulative probability" of detecting, tracking and destroying reentry vehicles, a Pentagon official said. Because the treaty prohibits multiple warheads on a single booster, "they could be developed for use on a much smaller booster and HIT will likely be tested with a single warhead on a small booster," the official added.
Under the Homing Intercept Technology concept, the interceptor would be command-guided by ground-based radar until reaching a high altitude.
Under the multiple concept, which officials' stress is not being developed, a large optical sensor would be operated on the Spartan to detect targets at very long ranges. On command the smaller warheads would be deployed with their smaller optical sensors used for terminal homing. The large electro-optical system is designed to have the capability of discriminating reentry vehicles from chaff, penetration aids or decoys, officials said. They added that the technology could also be used in an anti-satellite mission.
HIT did not die a sad death.
LTV kept on developing it, and a direct descendant of it was used in the famous Reagan era ASM-135 ASAT tests.
Later, LTV asked "what if we made it a radar guided missile instead of an infrared/optical guided missile?"
Thus was born SR-HIT (Small-Radar Homing Intercept Technology).
SR-HIT became FLAGE (Flexible Light-Weight Agile Experiment); a fire and forget missile with no commands given to it post-launch. FLAGE ended on 21 May 1987 with the successful intercept of a LANCE missile and became...ERINT (Extended Range Interceptor), which was mid-course command guided, and became...the Patriot PAC-3 missile.
So there you have it. A direct lineage from the SAFEGUARD ABM to today's ABM.
"If scientists and inventors who develop disease cures and useful technologies don't get lifetime royalties, I'd like to know what fucking rationale you have for some guy getting lifetime royalties for writing an episode of Full House." - Mike Wong
"The present air situation in the Pacific is entirely the result of fighting a fifth rate air power." - U.S. Navy Memo - 24 July 1944
It was definitely AHIT, or at least a part of the program was so labeled (the hardware being a +/- 3' tall rough cylinder with fuel tanks and rocket nozzles, that flew tethered over a net for about fifteen-thirty seconds at a time). Maybe as you suggest, it was some particularly obscure part of the program...
Now I want to go comb through the old files and notes to see if I can track down what that "A" stood for. Although I'm pretty sure I never knew, even at the time...
I find myself endlessly fascinated by your career - Stark, in a fit of Nerd-Validation, November 3, 2011
"This cult of special forces is as sensible as to form a Royal Corps of Tree Climbers and say that no soldier who does not wear its green hat with a bunch of oak leaves stuck in it should be expected to climb a tree"
— Field Marshal William Slim 1956
It took three seconds, like I was saying DTIC solves these problems.
"This cult of special forces is as sensible as to form a Royal Corps of Tree Climbers and say that no soldier who does not wear its green hat with a bunch of oak leaves stuck in it should be expected to climb a tree"
— Field Marshal William Slim 1956
Winston Blake wrote:The range of the Iron Dome missile is apparently 70km. The range of a Tunguska's guns is 4km. A simple ratio of areas, 70^2/4^2, implies that at least 306 Tunguskas would be needed to protect the same area as a single Iron Dome launcher. The true number will be higher because you need to create an overlapping circle pattern.
Wrong. The only thing you need to cover is Gaza Strip/Lebannon border, and only in places where a city or settlement is in the range of Kassam rockets.
OK, I overestimated that. However, Iron Dome is almost certainly part of a larger, long-term air defence program, and if your defence policy is to be able to stop Iranian fighters from bombing (or nuking) you, you will need an integrated missile-based system anyway. Making a gun system saps time, money, and labour away from that goal, making it a bad investment.
A Tunguska costs $16 million each. 16*306 = 4.9 billion dollars... but this is with the missiles. Even if a gun-only system only cost $1 million, that's still in the range of hundreds of millions of dollars each, compared to 'tens of millions' for an Iron Dome battery.
That was exactly what I postulated. No tank, no armored turret, etc, just cheap gun system targeting incoming pipe rockets. At your cost, 1 mln $, one Iron Dome battery less would buy 'tens' of such systems, which then proceed to take out badly welded chunks of canalisation for ~100$ [link to 30 mm HE round price from quick google] a pop, not 65.000$.
Also - it fired 40 missiles to defeat that last wave of 120 300$ rockets. That alone is 2.6 mln $ that would have paid by ~3 such systems by itself, isn't it?
Yes, I know that's what you postulated, that's why I said 'but this is with the missiles'. Further, you don't seem to have appreciated that I threw out $1 million as a ridiculously low number, considering the cost of a Tunguska and other multi-million-dollar vehicles. I don't have the knowledge to guess how much it would actually cost, but the radar and electronics alone must surely cost several million dollars.
Thank you for finding a number for the cost of 30x113mm ammunition. It implies that 30x165mm & 30x173mm ammunition must be considerably more expensive than $100 each, even in basic mass-produced form which has no self-destruct mechanism. Presumably Israel would use 30x173mm NATO, considered they already manufacture systems using it. 30x173mm ammo has about 3x the powder of a 30x113mm round - and you'll need it to hit air targets at 4km. I would not be surprised if properly fuzed 30x173 ammo cost >$200 a cartridge.
You say that your gun system will cost '$100 a pop, not $65,000'. You seem to think that a SPAAG can reliably kill a target 4km away with a single shot. You also bandy about numbers like 'hit ratio to something approaching 100%'.
Link wrote:"The cannons are fired alternatively with a combined rate of fire of between 3,900 and 5,000 rounds per minute (1,950 to 2,500 rpm for each gun) [...] Bursts of between 83 and 250 rounds are fired as determined by the target type, with an engagement range between 0.2 and 4.0 km and to an altitude of 4 km. [...] The 9K22 is reported to have a kill probability of 0.8 with cannon".
Note that at 5000 rpm, 83~250 rounds is exactly 1 to 3 seconds. The one second burst in that video, at 0:31, contains about 83 rounds, and is a wide 'cloud', most of which will miss the target (and Qassams/Grads are smaller than planes). $100 per round is a lower limit, so a lower limit on the cost of a volley is $8,300 ~ $25,000. Further, that '0.8' number is certainly not the kill probability at the maximum effective range.
Also, although I'm not sure, I expect that the '250 round burst' is just that, one burst. Multiple bursts may be needed to destroy a target. I expect that between max-length bursts the guns must cool down briefly and cannot fire.
While we're talking about gun-based point-defence, the video below shows self-destructing shells at night, at 0:55. These volleys do not cost $100 a pop. It's not clear to me whether you were intentionally comparing projectile cost, rather than cost per kill.
Also I expect that gun volleys of several hundred rounds will cost significantly more than '$300~$400' a pop, but I can't find good data on this. Also, those hundreds of self-destruct fuzes must be near-100% reliable, lest you accidentally shower a neighbourhood with stray 30mm cannon rounds. This would drive up the cost of ammo, and thus of a volley. A missile only needs one self-destruct mechanism, and all the hardware needed is already on the missile.
A) You'd need to burn ~650 rounds before approaching cost of a single missile. Modern systems are capable of killing unguided rockets with a short burst, it wouldn't use 650 rounds to defeat the entire described attack of 120 missiles.
You're right, you wouldn't use 650 rounds to defeat 120 missiles. A Tunguska would need 9,960 rounds to fire a single minimum-size 83-round burst at each target, costing a million dollars even at the price of dinky 30x113 Apache ammo, and probably >$2 million realistically. And that's assuming you can get 100% kill probability with just 83 rounds each.
B) Note you're spraying in the direction of Palestinian border, into area that is often under rocket attack anyway. Read, into expendable land. That thing would sit between city and launch site, not in public park. Also, modern anti-air shells are HE anyway, they are more reliable in this regard than a missile, and a single 30 mm round weighs nowhere near weight of ID rocket.
Placing the guns so rounds only fall in enemy territory forces you to use many more - I'm doubtful that this would save money overall. I can't understand the purpose of your last sentence here. I will note that an Iron Dome interceptor weighs 90kg, whereas a 30x165mm projectile weighs 270g. One interceptor only weighs as much as 333 shells, or 108 complete cartridges.
Each 250 round burst from a Tunguska puts 67.5kg weight of shot into the air, which is comparable to the Iron Dome missile's initial weight. The weight at impact will be much lower, since most of the missile is propellant, a large portion of which gets used up during the initial boost phase. I would not be surprised if the weight in the air at impact is much less than that from a gun burst.
While we're talking about weight, a 250-round burst from a Tunguska requires the vehicle to carry 207.5kg of ammunition (whole cartridge: 890g). The entire vehicle only carries 1,904 rounds (1,580kg) , giving 7.6 bursts. On the other hand, 8 Iron Dome interceptors weigh 720kg together. It gets worse when you add in the weight of the guns, actuators to drive the guns around, the ammo-handling system, and cost/maintenance for all that stuff.
As shown in the OP, Iron Dome uses VLS launch. The boxed missiles are simply stuck on a frame on the ground and do not need to be traversed or elevated, and can fire instantly in any direction, at multiple targets at once. Modern practice is to make boxed missiles 'sealed rounds' which require zero maintenance. Once you have built the factory, at high investment cost, you can just churn out box after box and add them to the existing system. As Simon Jester mentioned, you also don't need to train and maintain crews for them. If you want to make fully robotic guns then that makes the system more expensive and less competitive.
You could well reverse the question and ask why risk adding to damage by spraying neighbourhood with rain of big rocket parts when remnants of a few 30 mm rounds are far less dangerous, IMHO.
It's not clear to me whether you were intentionally distorting this. We are comparing highly unaerodynamic junk which will lose energy rapidly, to intact 30mm shells which failed to self-destruct (not 'remnants', as you bizarrely suggest) and are still full of HE.
I don't postulate to replace ID with this, I just wonder why Israel spent hundreds of millions of dollars when a fraction of that would have supplemented Iron Dome's 85% hit ratio to something approaching 100% at fraction of the price. I can see coverage argument, but...
I think that you think guns are much better-performing than they really are, and much cheaper than they really are.
Especially seeing they would have liberty to intercept all missiles then, not just 1/3, potentially saving a target ID programmers missed and sending much better message to Palestinians than 'we'll spend two orders of magnitude (two hundred twenty times!) more per rocket to intercept 1/3 of your missiles so keep sending 'em to bankrupt us!' one.
The system which tells you if it's going to hit an uninhabited area saves you money, risk, and labour regardless of whether you're using guns or missiles. The program managers would have to be idiots to throw that away for some kind of pointless PR victory. Israel is not at risk of being bankrupted by this program, and in the grand scheme of things, they need the best missile-based air-defence system they can get anyway.
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Regarding Iron Dome's problems targeting rockets coming in from less than 4km, I found the following article from 2010 containing statements about Israel's actual policy against Qassams/Grads/etc:
The source said the media had failed to understand the real purpose of the system; reporters have described Iron Dome as a routine means for intercepting Qassam rockets and Grad-type Katyushas.
"This is a system that is expected to counter much bigger rockets that may be in the Gaza Strip, like the Fajr-5," he said. The Iranian-made Fajr-5 is in Hezbollah's arsenal and has a range of 75 kilometers. It carries a warhead of between 100 and 150 kilograms.
On the other hand, the source says, bomb shelters and the "Color Red" air-raid alarm will remain the main way to deal with Qassams and Katyushas.
"There is no point in routinely firing intercept missiles against a single Qassam," the source said, noting that Qassam attacks have been rare since Israel's military operation in the Gaza Strip a year ago. "Iron Dome should be used at times of escalation or against bigger rockets."
Another factor, apparently, is that since the number of operational batteries will be small at the outset, the IDF wants to avoid a situation in which one town receives permanent protection while its neighbor remains vulnerable.
"The IDF developed its operational doctrine for the Iron Dome system by taking a comprehensive view, out of an understanding that it is necessary to provide an effective response to a wide range of threats, and in several theaters of operation, on short notice," the IDF Spokesman's Office said.
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Irbis wrote:I cut out the political/obsolete parts of the article, but still... I wonder, how many automatic guns could 300 mln spent fortifying homes bought instead? Guns that would be of much greater use for the role even if that issue with launch time was somewhat fixed?
The launch time issue seems to be a software performance problem and might be relatively easy to fix, and Iron Dome wasn't designed for sub-4km Qassam shots.
However, ignoring the whole Iron Dome thing, this fortification plan doesn't seem like a good idea to me. The area in question:
The 'problem zone' is the green strip. They decided to spend USD$89M on fortification (300 million Israeli shekels). For this they can fortify 3600 out of a total of 8000 homes in the green strip, in the next 2 years. It may actually be better to buy point-defence systems to protect these 7 settlements. The settlements seem quite small on Google Maps - only 2-3km in diameter.
I do not know if guns or short-range missiles would be better, and I do not really know what systems are on the market. I hope Sea Skimmer will weigh in.
Robert Gilruth to Max Faget on the Apollo program: “Max, we’re going to go back there one day, and when we do, they’re going to find out how tough it is.”
Its been a long time since I checked up on laser technology as an interceptor weapons. Wouldn't it be ideal for this situation? Does anyone know how far away from field operations they are now?
cosmicalstorm wrote:Its been a long time since I checked up on laser technology as an interceptor weapons. Wouldn't it be ideal for this situation? Does anyone know how far away from field operations they are now?
Five years maybe for a particularly useful laser air defense weapon to be actually fielded. Stuff that would work could be fielded right now, but it'd be so expensive and operationally limited its not going to be an advantage over a proven system like Iron Dome. THEL is dead and its toxic chemical fueled technology is limited and dated, solid state lasers can also now do its job if you wanted to spend enough money ganging them together to get the required power. Very inefficient but it beats the truckloads of toxic gas.
If anyone wants to look up what the current state of the art programs are a couple names to Google would be Joint High Power Solid State Laser and High Energy Liquid Laser Area Defense System. The Airborne Fiber laser and Free Electron Laser are long term approaches then the programs above.
"This cult of special forces is as sensible as to form a Royal Corps of Tree Climbers and say that no soldier who does not wear its green hat with a bunch of oak leaves stuck in it should be expected to climb a tree"
— Field Marshal William Slim 1956
