First of all, not sure how I missed that batshittery post from a while back. Love it. That Sprint's gotta home in on an attitude reading immediately upon exiting the ground because of the nutzo acceleration as the engine turns on. Your best bet is pointing it as straight towards the final heading as you can before it gets going, or else it's going to lose control, or at the very least waste a lot of fuel. Very impressive tech for that era. Though the atmosphere may shield you from radiation before e.g. Trump's radioactive hurricane arrives, the problem with ground-based defense systems is the atmosphere. The thing that ablated and destroyed Sprint missiles. If I were to keep one national secret as secret as secretably possible, it would be a relatively robust space-based missile defense system. It could be fairly easily miniaturizable; a satellite constellation in polar LEO orbit would provide an initially large velocity for any launched missiles, and the lack of atmosphere throughout the trajectory would require much, much less fuel. I dunno, even if the Iridium constellation was secretly packing ten micro-missile interceptors in each satellite (lol it's not), that'd still only be about 750 intercept chances. It's like 90 min./orbit in LEO, so the logistics are daunting if Russia launched a whole buncha ICBMs quickly. Honestly, I don't think that the public-facing technology (I know of) for microsat-scale (and especially cubesat-scale) stuff is advanced enough to indicate it possibly being driven by a secret and sizeable gov't program(s). Car-sized satellite systems seem to be where it's still at. And those're harder to hide, obviously, but surely Russia has similar tracking capabilities vs. US, which should extend to resolving satellites of sizes down to < 10 cm -ish. So cubesats. You're right though, public domain says we do only have a li'l defense thang. Sounds like it deserves nothing more than such verbiage. Maybe we could just not do nukes.? Everywhere? chanting DE-VALUE PHYSICISTS! (repeat)
Fuel... was a non-issue. The thing was a solid rocket motor made of nitrocellulose, zirconium and nitroglycerine that it used to get two kiloton neutron bombs within electronic-melting distance of nuclear warheads at re-entry speed. It was designed to airburst between 5,000 and 95,000 feet. It is left as an exercise for the student to determine the effects on the ground from a 2kt neutron bomb going off thousands of feet away. Obviously better than a 550kt thermonuclear device going off thousands of feet away? but not great. I've lately taken to getting rid of the fruit flies spawned by the pears my daughter didn't eat by lighting a poof of purell spray with a lighter. It doesn't kill the flies? It turns them into failurebeetles. MIRVs popped by a Sprint would still be, uhm, ballistic penetrators and uhh dirty bombs but that beats the alternative. I wasn't much younger than I am now when I realized this was our deterrent strategy when I was a kid: Thing about a secret missile defense system? It lacks deterrence. You wanna brag that fucka from the rooftops, like Reagan and SDI. Did we ever do more than a couple lame-ass tests? No. Did Gorbachev literally offer to discard all nukes if Ronnie was willing to drop SDI? According to David Hoffman, yes. It also violates two or three treaties off the top of my head and that's the sort of thing you don't want to be accused of at the UN Security Council. It's been pointed out that decoys are 1:1 effective against interceptors and hella cheaper. R36 will haul 10 warheads; make the payload fairing twice as long and it'll haul 9 warheads and 11 decoys. "strange game. The only winning move is... not to play"
My not-much-fuel argument serves only to play into the miniaturization and quickness of response arguments. So, Missile Command 1980, but with the turret at the top of the screen (in spaceeeeee), pointed downwards, and the ICBMs traveling by horizontally, in the upper exosphere, but your intercept missiles are hella faster. Surely one could build a killswitch such that once a nuclear bomb system is armed, Uranium cores are forced together via a powerful spring or something upon the loss of electricity and thus initiate the chain reaction, at altitude or otherwise. Looking forward to seeing the FBI tomorrow, at this point, thanks. There is also at least some value to a quasi-secret defense system, in which, say, only the Ruskies know about it, but maybe we know they know, and they can't divulge too much publicly without revealing something fairly compromising. Ugh, who knows. I kinda hate intelligence agency games. You very quickly have to get into the error bars / uncertainty.
10⁵ cm/sec is over 2000 mph; that's a powerful spring. Richard Rhodes described a number of improvements to the gun design used in the atomic bomb. A 21-foot barrel was already too long to fit in a B-29, and facing smaller guns at each other raised difficult timing challenges. High muzzle velocity was essential: "Typically the chain reaction takes less than 1 μs (100 shakes), during which time the bullet travels only 0.3 mm." In April 1943 Seth Neddermeyer was attending ordinance discussions at Los Alamos when he hit on the spherical implosion design. This would prove an exquisitely difficult engineering challenge, but the war provided urgency. Another engineer had a more prosaic insight: the five-ton Army gun under consideration was sturdy enough to withstand multiple firings; a bomb gun would be vaporized on first use and could be flimsier and lighter. But it was still very long, hence the design was nicknamed Thin Man. Later that year Emilio Segrè made the final essential contribution to a portable gun design, measuring rates of spontaneous uranium fission at the secluded Pond Cabin, "one of the most picturesque settings one could dream of." He found that the rate of spontaneous fission in U235 was higher at elevated Los Alamos than at sea-level Berkeley. Cosmic rays caused the higher rate of fission, threatening to detonate the critical assembly early, resulting in a fizzle. Cosmic ray shielding reduced the minimum muzzle velocity, allowing use of a smaller gun, and Little Boy was born.a powerful spring or something
Cool notes! I assumed that the bulk of the chain reaction would take place over some fraction of a millisecond, but it's even faster, a microsecond. So yeah, you gotta use a spring (or a gun) anyway. Or spherical implosion. ...Is mk subpoenaed yet or do we have to keep going?
Awww, c'mon man I know it's boring down here in my land of Newtonian mechanics? But at least the math isn't controversial. 800 warheads in Russia, 600 on subs, 200 in bombers. I think we can agree that a coordinated first-strike by Russia is not going to go off smoothly. I think we can also agree that the most likely successful launches are going to be from subs. An R29, launched from the geographic center of the Gulf of Mexico, will hit San Antonio in 2 minutes. And, by the numbers above, will have around 1400 friends. What does a practical deterrent against that look like? Fuckin' Darth Vader couldn't pull that shit off with the Death Star. An Iridium constellation made of Death Stars is going to have a tough time killing 1400 penetrators. Let's assume whatever we have is as good as Iron Dome (85%) because improvised Hamas ballistic weapons, Russian ICBMs, same same. I'm gonna need about 1700 somethings, I'm going to need them with close-kill capability against stuff coming up 20 miles offshore at 15,000 mph, and they're all going to weigh as much as a Miata. There's a reason we abandoned missile defense. Wanna see it? Russian/Soviet/Russian doctrine has always been "stack bodies." At the time we were seriously contemplating deploying Sprint missiles? The USSR had 47,000 warheads. Because we're American, we decided that since we couldn't defend everyone there was no fucking point. Because they were Soviet, they decided they only needed to defend Moscow. Doctrinally? They have an advantage. "Defend the Kremlin" is a much easier task than "defend the fourth largest country by land mass in the world." You wanna know what a secret defense system looks like? It looks like first-strike. If we had anything up there - and we don't - it would have one job: Kill Moscow. You can talk about error bars/uncertainty but this was an entire industry for 50 years, it's not like this shit hasn't been wargamed a dozen different ways. And you're not going to spend any money without wargaming it a dozen different ways. There's no magic bullet, man. The minute either side decides to launch a first strike, the other side will launch a last strike and the future is up to the cockroaches.
A secret defense system more likely looks like signals jamming, but I digress. Great thread, brah, thanks :).
I'm curious what signal you'd be jamming, theoretically? Nukes are truly fire-and-forget. Doctrine is to keep the arsenal high-survival until you loose the doves. https://upload.wikimedia.org/wikipedia/commons/b/b2/World-wide_delivery_in_30_minutes_or_less.JPG The whole point of the exercise, from an American standpoint, is "get shit aloft in the amount of time between 'detection' and 'annihilation." Doctrine relies on a successful vengeance strike when C&C is assumed to be radioactive vapor. Meanwhile, the Soviet standpoint was "get shit aloft AFTER we're radioactive vapor because there's no way we can launch in 30 minutes."