Panofsky:
The history of MIRVs is again complicated, because MIRVs
have more than one mission. Uh, quite early uh... it, the Soviets
started becoming active in deploying ABMs. They first, they built, starting
building an... a defense around Leningrad, uh, then they took it down again,
because it was ineffective, and then they started building around Moscow.
And, of course, at those days, the intelligence information was somewhat
scanty, and obviously we didn't know how far they would go. So therefore,
uh, in order to preserve our deterrent against a potentially emerging ABM,
we worried how to penetrate ABM, and the primary way to counteract an ABM is
what is, what's known as penetration aids, and penetration aids of two
kinds: things which one calls "endoatmospheric" and "exoatmospheric."
Exoatmospheric are light pieces of chaff or, uh, other light objects in
outer space, which presumably the, the radar of the opponent could not
distinguish from the real reentry vehicle, and therefore would give them so
many targets to track and to tar-, uh, uh, and to, uh, destroy, that ABM,
the defense would be ineffective. However, if the other side can wait long
enough for these reentry vehicles and the chaff to enter into the
atmosphere, then the decoy, the chaff, the so-called exoatmospheric decoys,
would slow down and the enemy radar could tell which is which. And
therefore, the obvious answer is to have, uh, heavier decoys, uh, and the
heavier they are, and the more they look like a reentry vehicle, the, the
less distinguish-, distinguishable they would be relative to a reentry
vehicle. But then the next step was, all right, I mean, if they, if it looks
like a reentry vehicle and smells like a reentry vehicle and acts like a
reentry vehicle, why not make it a reentry vehicle and put a bomb in it? So
therefore that was basically the birth of, uh, MIRVs, or rather, first the
MRV's, namely multiple-reentry vehicles, uh, because... that idea was simply
borne by the fact that if you wanted a decoy, um, the real RV, with decoys,
which are really undistinguishable, uh, from the reentry vehicle, then very
little additional weight is involved, and you actually at the same time put
a weapon on it. So that was the beginning of MRVs, and then came MIRVs.
Now, the interesting fact, of course, is that that sort of prompted the
idea, but then it became clear that the ABM threat had been greatly
exaggerated, that the Russians proceeded quite slowly with the ABM
deployments — as I said, the initial deployment... around Leningrad was
taken down again; the, uh, deployment around Moscow never grew to more than
64 interceptors; so you don't need such a very complicated system to
overhang just 64, uh, intercepting, uh pieces of ammunition, essentially.
But nevertheless, by that time, uh, the, our military discovered that MIRVs
could serve quite a few other missions, other than simply penetrating the
defenses of the other side. Uh, it was discovered that that was a good way
to simply be able to target more objects in the Soviet Union less
expensively. And, um, uh, so that... with a lower investment in number of
launches on our side, you still could have more targets. And, um, you could
also target them with fairly good precision. So, uh, so as our strategy went
considerably beyond sort of the idea of having a minimal deterrent to
inflict unacceptable damage to the aggressor, but when we looked at actual,
more complicated doctrines, uh, which involved targeting, uh, many other
military targets, then being able to cover all those, uh, became an
attractive idea, and MIRV started to have a life of its own, beyond being
just a penetration aid. Then, there's another technical matter, and that is
the fact that if you put one heavy bomb on one warhead, uh, and attack a
city, then you can damage a certain area, which is quite large, but in the
middle of the area you're overkilling, uh — that means you're pro-, you're
producing so much extra heat and blast that ..., it, it doesn't, it wouldn't
make any more difference. If you have more than one warhead on the missile,
then the, what is known as the footprint of that, uh, launch, can be widened
by spreading out the individual warheads. Now for that you don't need an
MIRV, but only an MRV... and it's, you need, not just... you... need a
multiple independently targetable reentry vehicle, but just multiple reentry
vehicles. And our early Poseidon A-3 missiles were MRVs, not MIRVs; they
simply were designed so they could widen the footprint and therefore do more
damage for a given total, uh, weight carat.