Anyone out there familiar with targeting strategy in the fifties and sixties? I’m assuming that multiple missiles were aimed at single targets, for redundancy, at least for critical targets. True or false?
[Evening update]
Folks, I honestly appreciate all of the info in comments, but I should have said that I need citable (i.e., non-classified) sources. They will go into footnotes.
You might find some info on http://www.fas.org or http://www.globalsecurity.org. The actual info you seek might still be classified so I hesitate to discuss it much. In the 1950s, there were very few operational ICBMs so it’s likely they didn’t assign too many of them to a single target other, perhaps, than Moscow. As the number of ICBMs (and SLBMs) increased sharply in the 1960s, there were more opportunities for redundant targeting. This is especially true after MIRVs entered service, greatly increasing the number of warheads available for targeting.
The reason I’m asking is that I’m working on the space safety paper, discussing the origins of human rating. I’m pointing out that early ICBMs weren’t that reliable, and they didn’t necessarily have to be, given their mission (which included redundancy in targeting). I want to make sure that’s right.
Of course, we’ll thankfully never find out just how reliable they were.
Based on their R&D flight test results, those early ICBMs (Atlas and Titan I) had pretty low reliability on the order of 70-80%. The learning curve was steep. The engineers said they learned more from a failure than they did from a successful flight. They learned a lot during those early years.
For the Space safety paper, I would recommend the Gemini Program Launch Systems Final Report, January 1967, prepared by the Aerospace Corporation, Aerospace report no TOR-1001(2126-80)-3, Contract no AF 04(695)1001.
It covers the logic of selecting the Titan after its initial 50% failure rate and the program to make it a human rated vehicle. I believe it also discussed the lessons learned from the Mercury program.
Shelley, is that available on line?
Rand,
The WorldCat shows it was published by the Aerospace Corporation in El Segundo, Calif. They might have a copy in their library you could look at.
http://www.worldcat.org/title/gemini-program-launch-systems-final-report-geminititan-launch-vehicle-geminiagena-target-vehicle-atlas-slv-3/oclc/4576436
It also appears to be available from Google Books, price unknown.
http://books.google.com/books/about/Gemini_Program_Launch_Systems_Final_Repo.html?id=lp3ApwAACAAJ
No data here, but I wonder how MIRV factors into the equation. First generation was one missile/one warhead, but when MIRV came around a single missile could substitute for a squadron. Did MIRV happen before or after people started throwing around ideas about limiting the number of missiles?
The peak total of US ICBMs was 1052. Of that, 1000 were Minuteman missiles and the rest were Titan IIs. The Titan IIs carried one very large (9 MT) warhead. The Minuteman Is and IIs carried a single warhead on the order of 1 MT. At one time, the Air Force wanted something like 10,000 ICBMs but Robert McNamara cut that substancially.
MIRVs came about later, with the first operational ones on the 3 warhead Minuteman III (1970). MIRV technology also allowed greater accuracy. Today, there are some 450 Minuteman IIIs in service. Most if not all only carry a single warhead now.
The peak was 1054 and occurred before propellant leaks began to decommission Titans circa 1980. In one case, where the leak was caused by a dropped screwdriver, the decommissioning was quite spectacular and resulted in a nuclear warhead being blown a couple of hundred meters from the silo. As far as I can tell, in the other case the leakage was spontaneous.
This may bear on the reliability question: if one aging Titan was lost to leakage just sitting in its silo, how many more aging missiles would have failed if subject to the rigors of launch?
Let me modify that to “dropped tool” — I don’t know that it was a screwdriver.
You’re right about the number (1054). I wrote a correction to my post but it disappeared somehow. According to WikiPedia, they actually fielded 63 Titan IIs. There were 3 destroyed in accidents including the one you mentioned with the dropped tool. IIRC, it was a large socket or socket wrench, not a screwdriver. A man died in that accident.
MIRVs offered several advantages. First, you had much greater flexibility in targeting because you had so many more warheads. Second, multiple small warheads detonating in the area of a target can be more effective than a single warhead that may not be as accurate. The post boost vehicle (or bus) used to individually target each warhead allowed for greater accuracy. I’ve seen unclassified statements claiming the CEP for a Minuteman III was on the order of 100 meters. I don’t know if that number is accurate, though.
Multiple warheads definitely makes missile defense more challenging. Not only are there more targets to engage, you can more easily include decoys and other penetration aids making it more difficult to discriminate fake warheads from the real ones.
At the Titan Missile Museum south of Tucson they have a display that references that indecent. I do recall that the object is described as a “tool”, but I also recall they have a large socket displayed. Can’t recall if there is something there stating “this is approximately what was dropped”.
I’m not certain of this, but I believe the major argument in favor of MIRVs was that they were needed to help US ICBMs penetrate Soviet missile defenses. Given the great difficulty even decades later of building a plausible defense against a mass ICBM attack, it’s hard to believe anybody could ever have taken this seriously, but it wouldn’t be the first time that major decisions were based on unfounded paranoia.
Missile defenses are hard for us now because we seek to knock the missiles down neatly and cleanly. In those days, interceptors were nuclear tipped, and they had a lot more margin for error.
Rand,
Reach out for Jerry Pournelle at Chaos Manor URL. I recall that he worked on methods to reduce the uncertainty ellipse for single warhead targeting, among other things. Been a while, so my memory is not as precise as I would like.
My understanding is that multiple warheads would be aimed at a critical target, especially if hardened, in part because guidance wasn’t as good as desired, giving a CEP larger than the effective blast radius against some targets.
Probably related, if Mercury through Apollo capsules could be reliably guided in to a pinpoint splashdown, a single ship could be enough to pick them up.
Peterh,
Yes, and that was the case for both Scott Carpenter and Gemini 8 with destroyers doing the honor both times.
But it was nice to have a fleet around in case the Soviets wanted to help “rescue” the crew from the water 🙂
I think the first operational ICBM was the Thor in 1959. They were all pointed at eastern Europe to stop the zerg rush of Soviet tanks that were expected to flood the west at the start of WWIII. With the advent of the thermonuclear device the CEP requirements went from thousand ft with a fission device to a couple miles with a fusion warhead. I’d imagine with that kind of accuracy they no doubt over lapped targeting. I also recall that our doctrine of nuclear war for most all the cold war was total destruction of all enemies both current and perceived. That means we were pretty much prepared to flatten the whole rest of the world if something like the cuban missile crisis had gone full defcon.
Thor wasn’t an ICBM but an IRBM (Intermediate Range Ballistic Missile). The Thor’s range was on the order of 1500 miles. ICBM ranges are typically over 5000 miles.
The world’s first ICBM was the Soviet R-7. It was the rocket used to launch Sputnik and is a direct descendent of the Soyuz booster. Our first ICBMs were the Atlas and Titan I. Like the R-7, they had to be fueled before launch. It was the advent of storable propellants for the Titan II and more importantly, solid propellants for the Minuteman series of missiles that changed everything. The Atlas and Titan I ICBMs were only operational for a few years.
It suddenly dawned on me right after I hit submit; ICBM’s — doh!
Rand,
What you are really looking for is their success rate.
Astronautix has some data for the Atlas D to F models that were deployed as ICBMs (A to C were test vehicles).
http://www.astronautix.com/lvs/atlasd.htm
Atlas D – 76.30 Percent Success rate
http://www.astronautix.com/lvs/atlase.htm
Atlas E – 68.75 Percent Success rate
http://www.astronautix.com/lvs/atlasf.htm
Atlas F – 71.70 Percent Success rate
Whether multiple or single warheads were assigned to a given target depended on calculated probability of kill and the value of the particular target. In the case of targeting an enemy ICBM silo, for example, the value of the particular target was largely the targeted ICBM’s own probability of kill — thus the silo of an ICBM of high reliability might be assigned 2 warheads instead of 1.
Rand,
The Titan I success rate was 78.57 percent.
http://www.astronautix.com/lvs/titan1.htm
Rand,
The Titan II (used on Gemini) success rate is listed as 92.59 %
http://www.astronautix.com/lvs/titan2.htm
A major improvement over first generation systems.
And do recall the famous shutdown of the Titan II in the first launch attempt for Gemini 6A. It also showed the value of having the astronauts in the abort loop.
http://www.astronautix.com/flights/gemini6.htm
[[[ Kenneth Hecht, chief of the Gemini Escape, Landing, and Recovery Office and long-time ejection seat specialist, was surprised when the crew did not eject, as they should have if ground, rules had been strictly followed. If the clock were right, then the vehicle had left the ground. Had it climbed only a few centimeters, the engine shutdown would have brought 136 tonnes (150 tons) of propellants encased in a fragile metal shell crashing back to Earth. There could be no escape from the ensuing holocaust. But neither Schirra nor Stafford had sensed motion cues; and Schirra, who as command pilot would have been the one to pull the “D-ring” for ejection, decided not to, despite the ticking clock.
At the moment of crisis, the veteran test pilot remained calm. With no trace of emotion in his voice, Schirra reported, “Fuel pressure is lowering.” Francis X. Carey, the Martin launch vehicle test conductor, was just as matter of fact over the radio circuit to the spacecraft. Just a hint of panic might have caused Schirra or Stafford to pull the D-ring. Schirra relied, with icy nerves, on his own senses. He knew GLV-6 had not moved, and he knew the clock was wrong.]]]
And those reliablilty ratings are just of the launcher. Actually delivering a non-dud warhead to the proper coordinates are less still.
Yep especially given the quality of the guidance systems.
I recall an old WSMR engineer telling of the time they were looking for a Redstone (IRBM) they launched. They found it in the very last place they expected it to be, right in the very middle of the target area. Later analysis showed it was a fluke, that two different set of errors in guidance just happened to balance out…
Legend also has it that a Minuteman II shot was a big factor in ending the Cuban missile crisis. The Air Force would put a camera boat at the aim point, in Kwajalein lagoon, as a matter of routine. And Russian “fishing trawlers” would sidle up before a flight. This particular flight, the single RV hit the camera boat and sank it, sending the Russians packing with their tails between their legs (they knew the significance of the location of the camera boat), and shortly thereafter ending the Cuban missile crisis.
As for targeting strategy, that probably is still classified…
My freshman AFROTC class, back in 1964, the instructor claimed ICBMs had an 80% reliability rate. There as no particular discussion of targeting strategy, but it seems reasonable that some targets — downtown Moscow for example — were assigned multipl missiles.
Rand –
Re: CEP. It’s my understanding that nukes were placed on missiles because their huge blast radius was the only way they could get the first [& second?] generation[s] of missiles to have a hope of destroying any hardened target smaller than, say, Moscow. As CEPs came down, as missile accuracy increased, warhead yields came down because the blast radius didn’t need to be so huge.
If a site was going to be hit with multiple nuke missiles/warheads, there would be a delay between detonations because, IIRC, simultaneous explosions over/on a target could cause something like self-cancelling over-pressure waves, resulting in *less* damage to the target.
Now nukes are, outside of MAD, just another high-yield payload that focused or specially-designed “conventional” systems can probably handle with equal or better results and significantly less political fallout.
I’m not a nuke scientist, and wasn’t in the Cold War nuke programs, so take it for what it’s worth. But I do recall reading these things from a reliable source [which I’ve obviously forgotten] some time ago.
The Bartelist
This post makes me think of that 80’s computer movie with Matthew Broderick, War Games. The simulations the computer ran for the thermonuclear war game showed multiple hits on the same city over and over.
I took a course (whose formal name I have forgotten, but which was called “Bombs and Rockets” by the students) at the University of Rochester from a professor named Mueller in the early 70s that discussed targeting and basing strategies and their historical development. Don’t know if it is still offered, but if you find a syllabus for that course or a similar one, your problem would be solved.
There is a book from the early 80s named “Better Read than Dead” by Thomas Nieman. It has detailed maps of all the major cities in the United States, overlaid with the number of targeted warheads and blast radius indicators. I remember the maps being quite detailed. It was particularly interesting to note that some areas had no thermonuclear targeting, but only neutron — such as high-density industrial areas and major ports. The heavy thermo saturations were mostly over major population centers and known missile bases.
I have no idea where my copy might be these days, but here’s the Alibris link if you’re willing to shell out some coin for a rare book.
I’ll dig around in the attic and see if I can find my copy, but don’t hold your breath.
The ‘Bulletin of the Atomic Scientists Sep 1979’ p. 24-25 says:
I’d say it’s a pretty good bet that , especially in the early days of ICBM technology, that missiles were redundantly pointed at individual cities. Given that you only had 15 minutes to strike all the targets you could before a retaliatory strike. It would be impossible given the technology of the time to re-target a missile if another failed to hit its target. And given that accuracy of early ICBM’s was rather poor compared to today, I’d expect missiles to be grouped together to insure maximum destruction of the target area.
Rand
The first generation in the 1950’s early 60’s were IRBM’s. That is why the Atlas was based in Turkey. That was part of Russia’s demand during the Cuban missile crisis, to dismantle the IRBM sites. Google that. Also, there is some good information in the book “Heavens and the Earth” The political history of the space age. Lots of footnotes that will lead you places there.
I think you typo’d that. Jupiter missiles were in Turkey.
If we were able to track incoming ICBMs, quickly launch our own ICBMs on a roughly intercept path, and then detonate them at closest pass, then ICBMs could also be defensive. This completely changes MAD where you have to build many more missiles than just that needed for unacceptable losses. It would seem that both sides did exactly that.
Can’t provide links, but I recall that the Russian strategy was different than the US strategy.
That is: The ‘more’ versus ‘better’ ideas carried over into missiles.
Living in Seattle, we’d hear about how many missiles were aimed at -us-. We’ve got major military bases north, south and west of us. And Boeing was also north + city-center + south.
That’s only six to ten or so real targets.
And yet the estimates for “Number of missiles aimed at/near Seattle” were often cited as in excess of fifty. Because they didn’t have the same levels of either precision guidance or maintenance.
And there was always NORAD.
Al,
Yes, Russia weapons philosophy at that time was keep it simple, build in mass and win by shear numbers. So it would not be surprising if they followed the same formula with missiles.