Intercontinental Ballistic Missiles

[Deepwater6]

http://www.space.com/19601-how-intercontinental-ballistic-missiles-work-infographic.html

 

I found this info-graph on ICBM's. I have often wondered if or when we ever had to proceed with an all out launch of our nuclear arsenal, What the predicted precentage failure rate would be. Then see the comparison to the actual failure rate.

 

I also realize that it's top secret, but I'd like to know what kind of safeties are in place. In particular when a missile is given the code to go, leaves the silo, but fails over US soil. Would the warhead already be armed at that point? Could they go off over US soil if they fell back to Earth?

 

With the amount of time the weapons have sat inside the silos I wonder about the reliability of the rockets. Also top secret is the maintenence schedule on the vehicles so maybe I'm wrong. Even so if it's an all out launch we won't get a 100% of them out of the country.

 

Then again at that point it really wouldn't make much of a difference anyway would it?

[CraigD]

I have often wondered if or when we ever had to proceed with an all out launch of our nuclear arsenal, What the predicted precentage failure rate would be.

The US regularly, though at least somewhat secretly, test flys its LGM-30 Minuteman ICBMs. According to its Encyclopedia Astronautica article, the failure rate over its entire 45 year operational history, which spans many replacements and upgrades, is 3.68%.

 

The US’s current arsenal of 450 LGM-30Gs are reported to have pretty good self-check systems, so my guess is their failure rate in an actual all-out war situation would be not much different than that, with about 17 of them failing to at least deliver their warheads in the rough vicinity of their planned targets. Russia is pretty good at maintaining and launching rockets (the part of an ICBM that must work to get the warhead at least near its target), so I’d guess their failure rate is similar to the US’s.

 

I also realize that it's top secret, but I'd like to know what kind of safeties are in place. In particular when a missile is given the code to go, leaves the silo, but fails over US soil. Would the warhead already be armed at that point? Could they go off over US soil if they fell back to Earth?

You’re right, DW - the technical details about nuclear weapons are pretty vigorously guarded secrets. However, it’s common knowledge that to maximize their effectiveness, nuclear weapons are designed to explode at a precise height above the ground (or in the cases of specialized, non-ICBM based “bunker busters”, after penetrating the ground). So their almost certainly electronically controlled fuzes aren’t truly “lit” until nearly the end of their flights. I think it’s essentially impossible for the warhead of a failed ICBM to explode in a nuclear way.

 

I've read about the possible accidental explosion of the non-nuclear explosives in modern thermonuclear explosives, but understand that, absent the precise timing needed to produce the weapon’s intended fission then fusion reaction, such an explosion involves energies on the order of the equivalent of kilograms, rather than hundreds of kilotons, of TNT, and are dangerous primarily because they scatter radioactive material.

 

With the amount of time the weapons have sat inside the silos I wonder about the reliability of the rockets. Also top secret is the maintenence schedule on the vehicles so maybe I'm wrong. Even so if it's an all out launch we won't get a 100% of them out of the country.

LGM-30s are solid-fueled, so are expected to be reliable for tens of years, given the maintenance of their non-fuel systems. While the technical details of this maintenance is secret, it’s cost is included in the US budget, a public document, and also in articles like the above Encyclopedia Astronautica one, so barring the unlikely possibility that a huge scam is being perpetrated, we can reasonably conclude that they’re being well-maintained.

 

All of the current arsenal had their solid rocket fuel replaced between 1998 and 2009, so it’s well within its expected service life.

 

And, as I mentioned above, Minuteman IIIs are regularly test launched.

 

Bottom line, I think it’s reasonable to expect that, in an all-out nuclear war, fewer than 20 LGM-30s would fall on US soil, and none of the warheads in these would explode.

 

Then again at that point it really wouldn't make much of a difference anyway would it?

It’s something of a grim exercise, but if, as I have on a few occasions over the years (always in the company of folk who like to do this sort of thing – that is, p&p gamers), you actually were to undertake the excercise of making reasonable guesses where all of the roughly 3000 nuclear warheads would be exploded in an all out-nuclear war, comparing it to the roughly 4400 cities with populations greater than 150,000, you’d likely agree with my conclusion that there would be at least hundreds of millions of people around after such an all-out nuclear war, who would care very much where and under who’s control any remaining nuclear weapons were. Even when the US and USSR’s nuclear arsenals were at their greatest numbers, the belief that an all-out nuclear war would kill all or nearly all human life on earth was more fantasy than reasonable speculation.

[Deepwater6]

http://www.cnn.com/2013/05/08/us/nuclear-launch-officers/index.html?hpt=hp_t2

 

Whoa, scary stuff, although the article gives the impression these guys could just put a code in and push a button I think there is more of a chain of command than that.

 

While that may be true here in the US I don't even want to think about what protocol that is used in middle eastern countries and Asia. As for Pakistan, my knees clang together and I bite my fingernails Yikes.

[C1ay]

I'm not going to elaborate very much but I am a former ICBM maintenance mechanic. Failsafes are in place to prevent a nuclear detonation at any point in the flight other than the destination. A particular sequence of events is required for a nuclear reaction to occur and that sequence is not enabled until it is time for the weapon to detonate.

 

Two keys operated by two officers simultaneously on separately received encrypted orders are required for launch and even then, those officers do not know where the target is. It is not as simple as a rogue President pushing a button in a briefcase.

 

Maintenance of ICBMs and the supporting facilities and systems is a routine daily task for missile mechanics.

[Deepwater6]

A fascinating job you must have had C1ay. Question for you, I understand some things you still cannot reveal and if that is the case just disregard my questions.

 

I saw the end of an action movie (T-3) a few days ago. At the end of the film the computer starts launching ICBMs Its a make believe Hollywood scenario nothing more. I did notice, and it could be just for the movie, that several ICBMs were reasonable close together. I mean to say two or three scattered on one farm in North Dakota and two or three scattered on another just down the road. Would that be the case? To keep them in fairly close proximity for protection and running a hard line back to a master control station nearby?

 

This land that houses them, are they eminent domain or do land owners get compensated? If compensated is it a yearly rate that can vary or a large one time sum?

[C1ay]

There are systems where one control station handles multiple silos but they aren't packed densely on one farm. They are all on government owned land.