Missle Defense Program...

[ToadMan]

Please define what you mean by work.

 

My biggest problem with missile defense at this point is that the criteria for success is that the interceptor missiles will be able to launch, and meet an incoming missile. The interceptor will carry a high enough yield such that it will knock an incoming ICBM out of the air. The interceptor will not be able to destroy a nuclear payload, meaning that the radioactive material will rain down on Saskatchewan, Alberta, Manitoba, and various other parts of Canada. Thus destroying the agricultural economies of said regions, and possible killing thousands from radiation poisoning. I digress. Let's assume that if the interceptor succeeds the incoming ICBM is neutralized.

 

Now lets do some quick calculations on the feasibility of M.D. I have some specs on the Atlas type ICBM. This missile is over 40 years old, but that will only serve to illustrate my point. If I can prove that the system is almost technically infeasible against a missile 40 years old, then we can by extension say that the system is totally infeasible against a current ICBM.

 

The Atlas ICBM (http://www.geocities.com/atlas_missile/specs.htm) validity of source is not confirmed.

"At the apogee of its elliptical flight path the missile reached an altitude of 763 miles and a speed of approximately 16,000 miles per hour. Elapsed time for a flight of 6,788 miles: 43 minutes."

 

Now I need to find the exact time an incoming ICMB will be detected. This will allow us to determine the maximum response time of the system. We all know that the earth is spherical, so an ICBM on an elliptical path, traveling a distance of 6788 mi will not be visible to a ground radar station until some time after it's launch. We will assume that the target is costal, hence the missile will not have to travel over any land. This assumption has two consequences: 1. The apogee is at the furtherest from the ground station, hence detection of the ICBM is the most difficult; 2. The M.D. system has the best opportunity to destroy the incoming transpacific ICBM over the ocean, which will avoid possible human causalities (however would be extremely harmful to marine life).

Earth curvature correction: (http://mathcentral.uregina.ca/QQ/database/QQ.09.97/dyck2.html)

8 inches / 1 mile

 

by mathematical extrapolation the flight of the ICBM can be modeled as

y = -(62.5x10^-6)(x-3394)^2 +763

where y is the altitude of the missile, and x is it's distance to the target.

 

The missile become invisible when 0 = (-(62.5x10^-6)(x-3394)^2 +763) - (15.78x10-6)x

 

x = 2600.37 by algebra and quadratic formula.

 

The missile is moving at an average velocity of 16 000 mi/hour. This means there is ~ 9.751 minutes until impact.

 

Now if we assume that the interceptor missile locks onto the incoming missile, and launches by the time the eta is 9 minutes, and the interceptor is moving at 16 000 miles per hour, then the interceptor will intercept the ICBM at a distance of 1300 mi.

 

Lets re-evaluate some of those assumptions. The ICBM is 82.5 ft long. A Boeing 747 is 231 ft long (http://flyaow.com/planes/74eaircraftspecifications.htm). Meaning the missile has a radar image of 1/3 the size of a Boeing.

I can find no statistics on the number of planes in the air at any given time. I believe a safe assumption will be that there are 200 planes in the area of interest (ie the area where the ICBM will be first seen). This means that the ICBM takes up 0.001786 of the visible radar images. Meaning that the missile is not even likely detectable. But if we assume that the change of the missile being detected doubles for every 1/2 of a minute it is visible (it will have traveled 50 mi in that time), then we can say that the missile will definitely be detected when 1 = (0.001786)*2^n n = 9.129 therefor the missile can be definitely detected at a time distance of 4.5 minutes. With the same assumptions about the interceptor, that make the interception at 600 miles.

 

That's not quite what I was hoping to see, but I must conclude that it would be possible. IF we can actually intercept the incoming missile.

 

The problem here in is that I don't know enough about radar targeting, and missile maneuvering. I can however say that trying to collide two missiles moving at 16 000 miles / hour, isn't going to be the easiest task. First one must know with absolute certainty where the incoming missile will be when the interceptor reaches it. An ICBM programed to change course once an interceptor is launched would therefor defeat the system. Further, an ICBM capable of masking or disrupting it's radar image will also defeat the system.

 

I'm not quite sure what I've accomplished, but I've worked on this post for too long to scrap it now.

 

I was hoping to show that it is unlikely that the system would work against a 40 year old missile, let alone a new ICBM. If I find some statistics on a newer ICBM's, then the same calculation may show that the response time of the system would need to be far to fast.

 

Well that's all I got.

 

Peace

[WinstonSmith357]

Two Reasons the Missile Defense Shield is a Terrible Idea:

 

1. It doesn't work. Testing so far shows that the interceptors rarely meet and engage their target and that's when the interceptors know where their targets are going to be. I'm sure any nation with BM's that has the intent on firing at a target on the US's soil will be very sportsman like and give a heads up so the US has time to prepare the new toy.

 

2. Assuming that it did work, it still won't stop anything that is not a ballistic missile. It doesn't even work for other types of missiles let alone more creative stabs at destruction. BMD wouldn't have stopped 9-11 or the Oklahoma City Bombing, which are the worst attacks on US soil to date. No ballistic missiles were used in either case, if I'm not mistaken.

[ToadMan]

touché

 

I'm looking for some information so I can prove whether or not an interception is a feasible reality. I have already kind of shown that detection is feasible (at least against a 40 year old missile). Now we need to show whether or not actually meeting two missiles moving at 16 000 miles per hour is feasible. I think the problem lies in the maneuverability of the missiles vs the required reaction time of the guidance system.

 

As for whether or not it would cause an arms race. I think that it's almost a guaranty. Anybody planning to launch missiles at the US will go to the lengths of attempting to defeat the M.D. system. It would be a waste otherwise. Realistically it will be a cold war, I don't think that either the attacking system, or the defense system would ever be tested.

 

Peace

[Sparq]

The ICBM is 82.5 ft long.  A Boeing 747 is 231 ft long (http://flyaow.com/planes/74eaircraftspecifications.htm).  Meaning the missile has a radar image of 1/3 the size of a Boeing.

Assumption or no, this isn't much better than a wild guess...unless of course you have done research on the subject, in which case I will stand corrected. A 2 ton truck has a radar signature much larger than a 747. A stealth fighter has a signature the size of a seagul. Angles and material matter more than sheer size. There is also the possibility that a missile may possess some stealthy design features...radar absorbant coating, for example.

 

We must also remember that the interceptor does not neccessarily have to strike the ICBM directly - like some anti-aircraft missiles, the interceptor could be designed to detonate early, spraying shrapnel into the path of the ICBM - at 16,000 miles per hour, even a small, low velocity object will do alot of damage when the missile hits it. The same concept has been considered for hunter-killer satellites, which would self destruct, throwing metal into the path of the target.

 

Then there's the counter-interceptor defences which have been ...theorised...for the ICBM itself - decoy warheads, chaff, and of course the simple fact that if the interceptor arrives too late, there will likely be 5 or more individual, self guided warheads in the air for every ICBM which was fired from the host country. That's alot of nukes.

 

I'd put more stock in orbital laser weapons.

 

I also think it's more likely that nuclear weapons will be...delivered...in smaller yeilds and quantities, covertly or via aircraft/artillery, on a tactical/strategic level, instead of en masse on a theatre level

Edited January 3, 2005 by Sparq

[ecnarf]

I'm completely against it.

 

It's not going to work, and it's useless. An anti-missile shield wouldn't have worked on September 11th, even if they were missiles that flew into the WTC and Pentagon (yes, I'm aware of the missile-hit-the-pentagon theory).

 

Even though the anti-missile shield was an idea brought about as an election promise, it's not going to work. Bush wants to re-build alliances (or at least try to), yet wants to install an anti-missile shield around the Arctic? People won't like it.

[ToadMan]

Your right Sparq. That was a wild guess. I didn't even think to reason out what would be a more accurate approximation.

 

Peace

[Sparq]

The estimate is probably fairly sound, assuming the missile does not employ stelth technology...and of course assuming that the wing surface of the 747, which a missile would lack, isn't the origin of most of its radar signature.

[ToadMan]

It also depends on the vector of the radar detector. If the missile is head on toward the radar detector, then all the detector will see is the 10 meter diameter of the missile. If the missile is perpendicular to the detector, then it's full length with be visible.

 

Also to note is that the 82 ft length is at launch, during flight the ICBM jettisons stages into space. Since the missile will not be visible via curvature until sometime after it's apogee then one could reasonably assume that at the point when we want to detect the ICBM it would be significantly smaller.

 

And yes if the missile was utilizing some kind of stealth, or radar confusion scheme, then detecting the ICBM, or more accurately predicting where it will be, will be even harder.

 

Peace

[Sparq]

That's the thing...this sort of defence shield will of course prompt efforts to counter it. Arms race, here we come.

Edited January 4, 2005 by Sparq

[HoboFactory]

toolbox, a missile defense is NOT necessarily moral, if for example it brings on the potential of distruction in a different and potentially more severe way. In that case, it is immoral on account of it being a stimulus for certain nations to create newer and more effective ways of killing each other. One has to think if long-term consquences regardless of which nation will present these consquences. But again, the system is already technically obsolete before its actual completion.

[ToadMan]

I'm not even sure it would be possible to build a defense system that wouldn't be obsolete at it's completion.

 

Peace

[toolboxnj]

toolbox, a missile defense is NOT necessarily moral, if for example it brings on the potential of distruction in a different and potentially more severe way. In that case, it is immoral on account of it being a stimulus for certain nations to create newer and more effective ways of killing each other. One has to think if long-term consquences regardless of which nation will present these consquences. But again, the system is already technically obsolete before its actual completion.

Now, I'm in the camp that's torn on Missle Defense, and even would oppose it if I had the power.

 

But, to question the morality of the issue is not the correct approach. We can go on and on forever, but the United States has the moral right to self-defense just as Canada does.

[Sparq]

I'm not even sure it would be possible to build a defense system that wouldn't be obsolete at it's completion.

 

Peace

A good point...ICBMs have been around, and effective, for a long time, but to date they still haven't made the interceptors work. Retrofitting existing missiles with stealth technology, or designing some sort of interferance system would likely be alot easier than building new interceptors to counter it.

[ToadMan]

If I get a chance I'll run it by one of my professors, they will have a little more real world experience with the kind of control systems that one would need to be able to effectively construct a missile interception system.

 

Peace

[Mouko]

ICBMs are extremely easy to detect with modern technology, ToadMan... satellites pick up the flare from the engines with ease. The size of the missile doesn't matter all that much-- the heat signature is more than enough to show everyone where the missile is. The engines in those things produce a lot of thrust and heat.

[ToadMan]

You say that as if it is thoroughly tested. The missile could implement thermal masking technology. The stealth bomber is not easily detected with thermal imaging. An ICBM could be launched under cloud cover, and could stay under that cover. As stated the ICBM would most likely posses many decoys that are able to confuses satellite imaging.

 

Peace

[Sparq]

Remember too that in the cases of many such missiles, the engines burn out near the apex...much smaller heat signature on the way back down. At this point you either need to calculate trajectory based on last known heading, or use radar.

[ToadMan]

That is true. Most ICBM's but Sir Isaac Newton in the drivers seat, using only small guidance thrusters for minor coarse correction.

 

Peace

[Mouko]

ICBMs cannot hide their heat signature... they need speed rather than stealth, and that's how they've been designed. The heat is so intense that they can almost always be detected shortly after launch.

[ToadMan]

Prove to me that there is no viable way of masking a heat signature. We're talking about a hypothetical missile that could be designed to penetrate a hypothetical defense grid. The missile could be built with a larger area, to diffuse heat over more surface area. The missile could utilize a jet style engine over a solid state booster. In the case of a jet style engine, all of the combustion is internal, so the heat just needs to be contained. That's not even a concern since there are very heat resistant materials available. Further to that, unlike with the stealth bomber, where you have to worry about a pilot, the only concern would be that the missile holds together long enough to reach it's target. The missile could also carry liquid nitrogen, and deploy it is a spray, if the calculations where done, then a satellite would not be able to tell that there was a large heat source masked by a cold source. The satellite would just see the thermals it expects. I'm fairly sure this would work, superposition applies to heat propagation.

 

But one thing that this thread is certainly showing is that for almost every suggested tactic of missile defense, a new delivery tactic can be developed to combat it. To build an effectual system, then every conceivable delivery strategy must be considered, simulated, and planned for. The system would have to consist of thermal, and radar detectors, both on the ground and in space. Other detection systems would have to be thought of to detect missiles that could defeat both of these systems.

 

Peace

[Mouko]

1. Larger missiles would require more thrust.

2. Jet-style engines are not practical -- remember, ICBMs reach the edge of space, or even space itself. They need solid fuel to provide the power to get that far. You couldn't have a jet-engine Saturn-V rocket.

3. Liquid nitrogen spray is actually already used in some missiles, but only to make sure the missile doesn't overheat during re-entry of the atmosphere. It might work, but it would need to be engaged immediately after ascent, because that's when the missiles are easiest to detect. Even then, there would be a suspicious cloud of hot and cold moving at several times mach speed.

 

As for the second part, I agree. It's impossible to defend completely against missile attack. Hell, some ICBMs even have countermeasures such as chaff, aerosol etc. to mislead anti-missile missiles. It's a very complex aspect of warfare.

[Sparq]

There's also the volume issue. Maybe you've got a grid that covers the entire country...but if they lauch their weapons en masse, you better hope you have enough interceptors ready to stop them all. And if they fire alot of decoys with the real nukes? Well, you're screwed.

[ecnarf]

There's also the volume issue. Maybe you've got a grid that covers the entire country...but if they lauch their weapons en masse, you better hope you have enough interceptors ready to stop them all. And if they fire alot of decoys with the real nukes? Well, you're screwed.

I think that's kind of overlooking the fact that it's extremely unlikely that a massive barrage of ICBM's from a foreign country is going to happen at all.

[ToadMan]

And what makes you think that?

 

Peace

[Sparq]

I also think it's more likely that nuclear weapons will be...delivered...in smaller yeilds and quantities, covertly or via aircraft/artillery, on a tactical/strategic level, instead of en masse on a theatre level.

I hate to quote myself, but I did mention that....but it is still possible, from at least two countries. Unlikely, certainly...but possible. But in that case, chances are the US is going to retailate with a cloud of their own nukes, at which point that's pretty much the end for everybody. In respect to serving the species instead of yourself, the best response to a heavy nuclear attack is no response at all. Just take it...your retaliation will probably doom everyone else on earth, if the initial attack didn't.

Edited January 7, 2005 by Sparq