You Might Want to Know: ICBMs Arriving - V. What Were the Things They Carried?
V. The Things They Carried
In the summer of 1969, we managed to get an astronaut on the moon, and get him back, which was the really nervous part for me. To get the three astronauts to the moon, we’d used a great big rocket we’d built called the Saturn V. It was taller than a football field is long. Having gotten our astronauts to the moon and back and doing it before the Russians managed to do it was very cool. For a while there, it had looked like they’d get there first. They’d beaten us to the first satellite and the first man in orbit and the first ICBM, remember.
But they’d faded. For a while now, we’d been pretty sure we’d be the first. I had.
The Saturn could certainly be used as an ICBM and would have been able to carry a warhead much heavier and more powerful even than the nine megaton W53 on the Titan II, but we didn’t plan to use the Saturn for that. Maybe because every launch of the Saturn V cost about a billion dollars. Today’s money. The Minuteman ICBMs were expensive enough, but for the same amount of money we could fire off over a hundred Minutemans.
Much better return on our investment.
Let’s don’t.
Secretary of Defense McNamara had decided that a thousand Minuteman missiles would be all the ICBMs we would have. Some members of Congress and the military had said we needed more. But he’d said No, only a thousand.
In 1969, the year we landed on the moon, we were well on the way to having that many Minuteman ICBMs ready to go. Two hundred were in my current neighborhood in that big stretch of prairie outside Cheyenne in Wyoming, Nebraska, and Colorado. The old Oregon Trail ran right through the missile field, as did I-80.
Beside the Minuteman ICBMs, we also had on alert now fifty-three or so Titan IIs, eighteen of them in the ground around my home town of Tucson and the same again around two other cities here out West. Ninety-some World War IIs of explosive yield, right there.
Some of these ICBMs might have been installed close to where you lived, if you lived west of the Mississippi.
And what about those “payloads” the ICBMs would be carrying? There was quite a story there. Scientists in the Manhattan Project, Niels Bohr for one, had said that after the war a nuclear arms race would be sure to start if we couldn’t find a way to prevent it, and if one did, nuclear weapons would be sure to get much lighter and more powerful than the horrible bombs dropped on Hiroshima and Nagasaki.
In the fifteen years since the end of the war, that’s exactly what had happened. The weapons had become, as J. Robert Oppenheimer once put it, “terribly more terrible.” And now we had also developed what Oppenheimer had referred to as the all-important “art of delivery” with missiles that could deliver these weapons coming in at many thousands of miles an hour, much faster than any bullet, far ahead of their sound. You wouldn’t be able to see the warhead or hear it. You’d know by the flash it had arrived.
By 1969, both we and the Soviets had come this far in that arms race that the scientists had said would be inevitable if we didn’t find a way to work with each other to avoid one, and we hadn’t. We might not have tried hard enough. Or wise enough.
The payload our first ICBM, the Atlas D, could deliver to other continents was the W49, at the time one of the lighter thermonuclear warheads we had. The bomb we had dropped on Hiroshima, Little Boy, had weighed over nine thousand pounds and had yielded the equivalent of about fifteen thousand tons of TNT. The W49 on the Atlas weighed less than a fifth of what Little Boy had and it had a yield of close to a hundred Hiroshimas, the equivalent of 1.44 million tons of TNT. That means that in the W49, we had improved our yield-to-weight ratio over Little Boy’s more than-five hundred thirty times.
The payload for the Titan I and the Atlas E and F models was the W38. It weighed twice as much as the W49, but yielded more than twice as much, 3.75 megatons. Its yield-to-weight ratio was seven-hundred sixty times better than Little Boy’s.
The heavyweight champion of ICBM warheads, for us anyway, was the W53, the warhead on our Titan II. The W53 yielded nine megatons, two and a half times more than the W38, twice the yield of all the explosives used by all sides in World War II, all by itself. It weighed over six thousand pounds but that meant it had a yield-to-weight ratio more than nine hundred times better than Little Boy’s.
But we weren’t satisfied with that. For the Minuteman I, we had two different warheads we could use. One was the W56, designed by the University of California Radiation Laboratory. It yielded 1.2 megatons, less than any of the warheads mentioned so far, but it weighed only six-hundred eighty pounds and that meant it had a better yield-to-weight ratio than any of those larger bombs, more than one-thousand one-hundred times better than Little Boy, the bomb that destroyed Hiroshima.
And those W62s and W78s on the Minuteman III and W87s on the Peacekeepers in MIRVs that we mentioned earlier? They weren’t quite as efficient as the W56 but they had even better yield-to-weight ratios.
Those were some of the warheads our missiles could deliver. Might we be reaching a limit here in terms of efficiency and yield-to-weight ratios? More than a thousand times better than Little Boy? Could be. Who could say for sure?
The Soviets’ warheads yielded more than ours as a rule but we didn’t think they were were as efficient or as accurate as ours. We could take satisfaction in that.
Next: What are “re-entry vehicles”? Why do we need RVs? How do they work? What are MIRVs? How do they work?