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General ICBM and nuke Info - updated

Posted: Thu Apr 27, 2006 10:21 pm
by Bolka
For those who would like some background information on nukes and ICBMs.


Defcon's central weapon is the ICBM (Inter Continental Ballistic Missile). The ICBM is a delivery mechanism, it is a long range rocket, it is launched from the ground (usually underground for defense reasons), flies into space, and then reenters the atmosphere to hit its target.
An ICBM is really meant to be long range (ie. over 5'500 km, 3'500 miles). For shorter distances, it is called an IRBM (Intermediate Range BM), travels much lower and slower, and actually may consist of a wider range of vehicles.
The ICBM is equiped with a nuclear warhead, that contains the nuke itself. In later developments, the ICBMs have been equipped with MIRVs (Multiple Independants Reentry Vehicles), consisting of several (as many as 12) warheads, with their own individual vehicle of reentry. This way one ICBM actually means several nukes.

Test of MIRV reentries

MIRV bus, each cone is a nuclear warhead

The first ICBM was the Atlas, it was operational in 1959, and it was a US development. The Soviet SS6 though was also operational shortly afterwards. The first ICBMs would travel at speeds around 1km per second (0.8 mile per sec), and have ranges from 8'000 to 12'000 km (6'400 to 10'000 miles). The payload would be of 250 to 500 kgs.

More relevant for Defcon, more recent ICBMs, as those entering in operation in the 70s, such as the Minuteman III or the SS-18 Satan, would fly at about 7 km/s (5 miles/s), or 4 km/s during reentry. Their range would go as far as 17'000 km, and would be able to equip MIRVs.

The cold war pushed many improvements on and around the ICBMs. In the 70s these missiles were designed to be stored and launched from silo 30m underground, that were shock isolated, had debris collection systems and were EMP proof. The launch control center had consoles to allow quick reconfiguration for targetting and launch. ICBMs were designed to hit hardened target such as other silos, and their accuracy went from 5km to a few hundred meters. Rentry vehicles were also equipped with penetration aid packages, that were counter measures decoys against ground fire, in particular interceptor missiles, and were radio controlable.


It is possible to intercept an ICBM pretty much in the same manner another type of missile is intercepted; with an interceptor missile. With ICBMs though, the speed factor makes it much less reliable. The main difference is the interceptor has to explode on the ICBM's path in front of it, because the ICBM's speed is higher than that of the explosion. Therefore if the interceptor explodes where the ICBM is, it will not damage it.
So interceptor missile should be able to destroy ICBMs provided they have the right software. Now, it would take many interceptors to actually guarantee to disable an ICBM, and there are only a few seconds during which the interceptor can catch it before it reaches its target.

The truth is there is no known means to defend a territory against a planned attacked of ICBMs. The damage can be reduced, but never entirely stopped. Even the US project of a nuke shield admits it would be efficient against isolated rogue attacks, but not against planned more massive attacks.


The most common form of a nuke is a one stage Atomic bomb, or A-Bomb, that uses the fission of large and not very stable atoms to generate tremedous amounts of energy, pretty much in the same way as in a nuclear plant.

The energy that binds an atom together is important, and by breaking an atom, this energy is released. The reason it is done with large atoms, is because they are less stable, therefore easier to break.
When an atom is broken, it will also eject particles, and if these particles hit another atom, chances are they will break it too. The idea in a fission chain reaction is that it reaches a critical point where atoms break each other at a steady pace, so as to get a self sustained fission reaction.

In a nuclear weapon, the goal is not only to generate this chain reaction, but to get the highest number of fissions to happen in the shortest amount of time, so as to create the most drastic explosion. The difficulty is to get the maximum explosion out of this chain reaction before the combustible is desintegrated by the explosion, which will stop the chain reaction. If the chain reaction is not extremely fast, the combustible will run out too soon and the explosion will fizzle.

So for a nuclear explosion, the process needs to be incredibly well organized, and this is the first great comlpexity of a nuke. This requires extreme mechanical precision, usually using laser machine tools, and much experimentation.
The second great complexity is the quality of the combustible, for nukes is has to be of extremely high purity, usually refered to as weapon grade quality. There are several ways to refine combustible to that quality, but all are complex and require time as well as much knowledge. The combustible usually used nukes are Uranium 235 or Plutonium 239. The purity of the combustible for weapons grade has to be higher than 90%. Natural Uranium is 0.7% pure.

The explosion of a nuke will release massive amounts of energy accross all the spectrum of waves and particules. Contrary to what is usually believed, the direct radioactivity of a nuclear explosion is not very important. Alpha, beta and gamma radiation is generated by a nuclear explosion in large amounts, but alpha and beta do not travel more than a few meters through air, only gamma, the least dangerous radiation type will travel far. Still, the other effects of the explosion are more dangerous.

One "side effect" of a nuclear explosion is the Electro-Magnetic Pulse (usually refered to as EMP). It is a very powerful electro magnetic radio emission, so powerful that it will just burn any electronic equipment in a very large radius around the explosion. In fact it is also a military strategy to explode a nuke in high altitude, so as to disrupt all communications over a territory. A high altitude explosion will also disturb the ionosphere, the electro-magnetic layer surrounding the earth, that is used to reflect low frequency radio, making long range radio communications difficult.

Other effects will include a violent shockwave, light of very high intensity that would blind temporarily if directly looked at, and an extremely loud sound. The explosion will generate heat in the order of 10 million degrees, which will also spread as a wave. Such a high temperature generates a strong air suction, that will suck large volumes of air, dust and debris right through the heart of the explosion, creating the "mushroom" cloud that categorizes nuclear explosions.

Nuke mushroom of Nagasaki, not edible

This cloud can rise high, over 10km above ground, and light dust can climb much higher still. This dust will fall very slowly wherever the wind takes it, and could go around the earth during the days following the exposion. Most of the radiocativity damage from a nuclear explosion comes from this fallout. The fission reaction generates fission products that are pretty well known, all of them radiocative. These are not dangerous immediately to man, but as time passes by they end up being eaten, and will go through our organisms. Some of them have chemical properties that makes them fix in bones or muscles.

Note that radiocativity is natural in certain doses, and the human body is actually well equipped to deal with radiocativity exposure. So it is really a question of how much radoactivity is taken and over what period of time. Ingestion of radioactive products will make levels higher, but not necessarily directly harm a person.

Levels of radiocativity on the explosion site can be very high and take much time to dissipate. This will depend much on the altitude at which the bomb exploded.


Nukes can also be enhanced with a second stage of explosion, which is a fusion stage. The fusion is pretty much the opposite of fission; it consists of forcing small atoms together. Such a process will generate even much more energy than fission, but needs extremely high temperatures to be started.

Since the A-Bomb generates such high temperatures, it simply needs to be surrounded with fusion fuel, and the reaction will be triggered by the A-Bomb explosion, effectively using it as a match to light up the fusion stage. The fuel used initially was Hydrogen, so this bomb is known as the H-Bomb, or the neutron bomb. Fuels used nowadays are fusion of deuterium with deuterium, or deuterium with tritium. The larger the particle, the higher the energy. Temperature generated by H-Bombs can reach as much as 400 million degrees.

This will drastically enhance the explosion intensity, but it will also make for a much cleaner explosion, since it will burn most fission products. The neutron bomb is very dangerous to living organisms, because it will throw neutrons in large amounts, at high speed, and pretty far. Neutrons will interfere with matter, but mostly leave objects intacts, effectivelly killing all life forms. Because of this the H-Bomb is considered a clean Nuke.


To further enhance the explosion, a third stage can be added, that consists of surrounding the H-Bomb with fissile material.
As the H-Bomb generates a massive amount of neutrons, and neutrons colliding with fissile matter will generate fissions, the layer of fissile material will act as a second botched A-Bomb.
In this case there is no chain reaction, it will just add more radioactivity and slightly enhance the effects of the explosion.
Such a bomb is considered a very dirty bomb, as it will generate large amounts of fission products for fallouts.

Posted: Thu Apr 27, 2006 10:38 pm
by false

Posted: Thu Apr 27, 2006 10:42 pm
by NeoThermic
The fact that you know all of that is beginning to creap me out. Do you have any kind of background in military tech that would explain how you know so much about nukes? :)


Posted: Thu Apr 27, 2006 11:55 pm
by Bolka
I am a mad scientist on a remote and unknown island (in fact the second picture of my post is me in my garage ;-)...

This is not so much information, it's all from the web. I have studied nuclear physics, and am pretty fond of it, but have no particular affinity with nukes. Still, as the engineer I am I find this type of information interesting.

Posted: Fri Apr 28, 2006 2:42 am
by Kumal
Well that was interesting.. I didn't understand it all but i'm pretty afraid of North Korean and Iran now.

And nice garage. How many cars you got? :roll:

Posted: Fri Apr 28, 2006 8:38 am
by tangostorm
I found this link that it could be useful. A bit easier to understand and provides useful information about people who wants to deepen they knowlegde about the reality beyond defcon.

Posted: Fri Apr 28, 2006 2:47 pm
by Slinken
Interesting text and great summarized, veacuse I am quite afraid of nukes.

Posted: Fri May 05, 2006 3:48 am
by Bolka
Added a new section on the nukes themselves

Posted: Fri May 05, 2006 5:20 am
by daset

Posted: Fri May 05, 2006 5:35 am
by NeoThermic
daset wrote:Me wanna nuke, me wanna nuke now!

*drops a nuke on daset*



Posted: Mon May 08, 2006 3:55 pm
by Verloc
sounds coooool!!I'm a little irritated with one of my working colleauges......can I nuke him??

btw,how does defcon actually work?is it real-time?

Posted: Mon May 08, 2006 7:47 pm
by mibias
hmm... im not sure... may i tell him? (im afraid i do something icepick dont want me to do, then he will come and kick me (im afraid of icepick))

Posted: Mon May 08, 2006 8:08 pm
by martin
Bolka wrote:I am a mad scientist on a remote and unknown island (in fact the second picture of my post is me in my garage ;-)...

cool, I'm one of them too :D

And while your garage is cool my lounge is better:


Posted: Mon May 08, 2006 11:03 pm
by Rynthas
A few nitpicks:
Combustible should be fissionable material, as there is a pretty important difference between splitting atoms and burning things.

Secondly, calling gamma radiation the least dangerous is a bit off. It's generally the MOST dangerous, just due to the penetration power. Alpha/Beta particles generally have to find a way into your body before they become very dangerous, as they don't have much penetrating power. Gamma, on the other hand, has no problem going through a few feet of concrete wall, and they're plenty lethal.

Posted: Mon May 08, 2006 11:08 pm
by estel
Gamma has a low ionising strength though; so you need to encounter it in much greater quantities.