Minimum effective range for ICBMs?

[Mr. Excellent]

What's the shortest distance an ICBM can effectively travel? I know they can hit targets on the other side of the world - but if someone took control of, say, a silo in Montana, could they hit a target in the same state? How about New York? Alaska?

I suspect there's a pretty high minimum range ICBMs are effective at - they're designed for suborbital flight, after all, not coming down really quickly after launch. But if anyone could give me the Straight Dope, that would be very cool.

[ChrisBooth12]

What would be considered an ICBM? If it hits the next city its not really Inter-Continental. How far does it have to go after launch? You could probably make a regualr ICBM blow 8 seconds after launch if you wanted to. Thats gotta be less then a foot travel.

[Otara]

Found this;

http://www.missilethreat.com/missile...ile_detail.asp

"Both versions were constrained by a minimum range of 600 km (373 miles) and an accuracy of 550 m CEP."

And this:
http://www.missilethreat.com/missile...ile_detail.asp

"The CSS-5 can deploy its 600 kg payload with a minimum range of 500 km (311 miles) and a maximum range of 2,150 km (1,336 miles)."

Which shows missiles do have minimum ranges, but it varies from missile to missile, assuming the references are accurate. Yes I realise the second one isnt really an ICBM, but I suspect the point stands.

Otara

[BrandonR]

Why couldn't the missile just travel upwards, make a giant turnaround (think incandescent lightbulb-shaped)and hit a spot a few feet away from it's launching point? Is there something technically restricting about IBCM's that I'm missing?

[SmackFu]

It would take a lot of energy to turn around, and by the halfway point, there is surely not enough fuel left for that.

[Jurph]

Originally Posted by BrandonR

Why couldn't the missile just travel upwards, make a giant turnaround (think incandescent lightbulb-shaped)and hit a spot a few feet away from it's launching point? Is there something technically restricting about IBCM's that I'm missing?

Yes. That would require a massive reprogramming of the guidance computer by the person taking over the silo. Most ICBMs are programmed to go up, tilt towards their target, and then slo-o-o-owly pitch over to the desired flight path angle. They also have a very very simple algorithm -- sometimes hard coded -- to run through the first minute of flight. Many of them can't effectively manage a loop because their gyros would lock up. Also, tilting too quickly while still inside the atmosphere (~100km) puts a bending force on the airframe, which is designed to survive mostly compression-only loads. Turn too sharply at too low of an altitude and you'll snap the missile like a matchstick using only aerodynamic loads -- a neat trick, but what a waste!

It would be possible to design a two-or-three-stage ICBM guidance program to drive the final stage backwards and let gravity take over, but this would require weeks or months of simulations to get right, a deep understanding of the guidance hardware, and the ability to completely reprogram the guidance software. For obvious reasons, most ICBMs don't make this easy; some older Soviet ICBMs make this flat-out impossible. Assuming you could do this, you'd need to drop the reentry vehicle on a shallow enough path towards the target to avoid burning itself up. So you've got to go far enough downrange that the RV's return path is shallow, but close enough that the second and/or third stages working together can get the RV back to the origin.

Assuming no modification to the guidance system, it basically depends what the guidance algorithm is, how good the RV's heat shields are, and how much velocity the first stage imparts. A very modern ICBM with a fast-burning first stage could perform an extremely steep first-stage burn, and as long as the reentry vehicle could handle the steep reentry (not a given!) then its minimum range could be very short indeed.

As for Chris Booth's question, an ICBM (according to the U.S. Missile Defense Agency's definition) can deliver its payload to a range of at least 5,500km. It does not have to exceed that range on every flight, nor carry the same payload on every flight -- the systems are classed according to their potential. You could take a system that could only go 5,000km (an IRBM) and replace the payload with a bowling ball, and you'd probably have an ICBM.

Oh, and one last anecdote. You can actually get an ICBM to launch and still hit its own silo if you use the "cold launch" method, but it's not a true launch. Anecdote from Astronautix.ru:

Flight trials of the missile with the 15F173 multiple-warhead bus began on 23 March 1986. The first launch was a tremendous failure. The cold-launch mortar fired, but the rest of the launch sequence failed. The missile exploded in the silo, blowing the 100 tonne silo lid far into the air and leaving only a huge crater at LC-101 Baikonur where the silo once was. The silo was beyond repair.

When they say "the rest of the launch sequence failed," they mean that the ICBM was lifted several meters clear of the silo by the "mortar", and then its guidance computer told the engines to start. They didn't. The missile achieved a very very low apogee and then returned to its silo tail-first.

[wevets]

Originally Posted by Jurph

The missile achieved a very very low apogee and then returned to its silo tail-first.

I would like to congratulate you on your excellent command of the comedic understatement.

[Stranger On A Train]

Originally Posted by Jurph

Oh, and one last anecdote. You can actually get an ICBM to launch and still hit its own silo if you use the "cold launch" method, but it's not a true launch. Anecdote from Astronautix.ru:

I'm guessing that was an SS-18 'Satan'/R-36. Hypergolic storable propellants = very nasty explosions. (We had some similar problems with the Titan II.)

I can do one better, though; I've got a video of a Minuteman (III, I think) launch where the missile leaves the test silo and does an (unintentional) nautilus maneuver. It was terminated by the Range Safety Officer before its trajectory becomes subterranean, but it did shower the silo and surrounding area with flaming chunks of solid propellant, which must have been a lovely mess to clean up.

I can't add much else to Jurph's excellent answer other than that modern ICBM warheads have as part of their arming systems a failsafe device that prevents the package from arming until it has achieved a ballistic orbit with such-and-such a speed, so just kicking it up and turning it around, even if the booster would survive those maneuvers, wouldn't arm the physics package, so a derranged madman or bodily-fluids obsessed general couldn't just reset the target coordinates of an ICBM to blow up a nearby city. That's what nuclear-tipped Tomahawks are for.

Stranger

[mks57]

Originally Posted by Stranger On A Train

I can do one better, though; I've got a video of a Minuteman (III, I think) launch where the missile leaves the test silo and does an (unintentional) nautilus maneuver. It was terminated by the Range Safety Officer before its trajectory becomes subterranean, but it did shower the silo and surrounding area with flaming chunks of solid propellant, which must have been a lovely mess to clean up.

One of the early Trident missile tests at Cape Canaveral had a similar problem. The guidance system went bonkers immediately after it was ejected from the submarine. The flight was terminated before it had a chance to go anywhere. It must have scared the hell out of the crew on that submarine.

http://www.fas.org/nuke/guide/usa/sl...906614_JPG.jpg

[Stranger On A Train]

Originally Posted by mks57

One of the early Trident missile tests at Cape Canaveral had a similar problem. The guidance system went bonkers immediately after it was ejected from the submarine. The flight was terminated before it had a chance to go anywhere. It must have scared the hell out of the crew on that submarine.

http://www.fas.org/nuke/guide/usa/sl...906614_JPG.jpg

I used to have that picture on my wall. That's actually a D-5 Trident II, so it's a later edition Trident (but a preproduction item).

Stranger

[Jurph]

Originally Posted by Stranger On A Train

I'm guessing that was an SS-18 'Satan'/R-36. Hypergolic storable propellants = very nasty explosions.

Yes, it was! I forgot to mention the two key points there:

(1) The fuel and oxidizer for the system are hypergolic, meaning that once they splash out together they'll automatically ignite, and

(2) The missile in question is one of the largest liquid-fueled boosters in the world, measuring over 3m in diameter and well over 20m long. That's over 150 cubic meters of propellant that are all going to mix explosively around an aluminum (titanium?) airframe.

Not only was the silo destroyed, the earth in which the silo was buried was so disrupted that the engineers decided not to even bother sinking a new silo there. If you knew where the launch complex was you might be able to find the wreckage on Google Earth. I know it's somewhere in the former USSR, so it should be pretty easy to find.

[Ravenman]

Originally Posted by Stranger On A Train

I used to have that picture on my wall.

You just reminded me: a colleague of mine got busted at a red light camera in Maryland. He insisted that he did not run the light, so he took the ticket to traffic court. He says he argued that there had to be an error in the camera. The judge said that the county paid a lot of money for those cameras, so he'd have to cough up some evidence that the camera was malfunctioning. Fully prepared for the moment, he said that the county paid $10,250 (or whatever) for that red light camera, which was made by Lockheed Martin, the same contractor who.... (pause for dramatic unveiling of that photo blown up to poster size)... spent $50 million on a missile that spun out of control seconds after launch. How on earth can we trust Lockheed Martin to know what they're doing?!?

He says the judge laughed and told him to pay the ticket.
[/hijack]

[Stranger On A Train]

Originally Posted by Jurph

Not only was the silo destroyed, the earth in which the silo was buried was so disrupted that the engineers decided not to even bother sinking a new silo there.

I don't think I'd go building a house there, either. UDMH and Nitro-tet do not make for a good garden fertilizer. It's one impressive rocket, though, and sufficient to scare the pants off of NATO planners, eventually stimulating the much-delayed development of Peacekeeper.

Stranger

[groman]

Originally Posted by Jurph

I know it's somewhere in the former USSR, so it should be pretty easy to find.

Start from here

here's a chart with a lot of ?'s instead of launch site numbers (according to above you're looking for launch site 101)

Old map