About a month ago you may have noticed, amid the overwhelming cacophony of Trumpian news punishment, that there was some sort of nuclear accident in Russia. A localized but relatively catastrophic explosion had taken the lives of a number of nuclear scientists near a place called Nyonoksa, located in the Arkhangelsk region of North West Russia, not far from Europe in general, and the Baltic Republics of Latvia, Lithuania, and Estonia in particular. There’s a Russian test facility up that way. Rosatom, the Russian nuclear agency, announced only that there’d been a mishap during “tests on a liquid propulsion system involving isotopes”, and that the incident happened on an “offshore platform”.
Before the typically Russian smokescreen of silence and misinformation descended, it was reported that the nearby town of Severodvinsk was experiencing a spike in radiation levels involving the isotopes Strontium-91, Barium-139, Barium-140 and Lanthanum-140, which would be typical products of the workings of a uranium fission reactor. Subsequently, video was released of a pair of damaged barges loaded with wreckage sitting where they’d been towed onto a beach, and left there by authorities. The video shows Geiger counters measuring high levels of gamma radiation emanating from the tow-ropes used to pull the barges, now discarded on the shore, as well as measurable in the air at a distance of about 150 meters from the wrecks.
As nuclear accidents go, this is a minor incident – it’s certainly no Chernobyl, though some radiation will inevitably waft westward into Europe – but it’s still highly disturbing on account of what we think blew up. The reference to a “liquid propulsion system involving isotopes”, combined with leaks gleaned by journalists from intelligence sources, led many to believe that the Russians suffered a catastrophic failure in a test (or perhaps during the post-test recovery) of a weapon designated “9M730 Burevestnik“, which has been given the NATO reporting name “SSC-X-9 Skyfall”. This is an experimental cruise missile touted loudly by Vladimir Putin last year as one of a series of new nuclear wonder weapons being developed by Russia’s noble scientists, and its chief characteristic is that it’s nuclear powered. Not nuclear armed – though undoubtedly it is – but nuclear powered. That is, it develops its jet thrust from the workings of a nuclear reactor, and that’s as scary as Hell.
Why? Well, a word or two on the technology and its military rationale is necessary (warning: techno-wonkish).
As the reader may understand, a whole host of modern cruise missiles functions just fine on the power of small, conventional jet engines – so why opt for nuclear propulsion? The main advantages would be theoretically unlimited range, and the ability to remain indefinitely at near maximum supersonic cruise speeds in the hypersonic realm. Such weapons could be launched at the merest whiff of trouble and left airborne to loiter, awaiting commands, for as long as necessary. They could remain on station for weeks or even months if need be, before being sent, if it came to that, on blistering low altitude supersonic runs towards their targets, which would have no way to defend against them (just how, exactly, you call them back if the crisis abates has not been explained). For Putin, they seem to represent a sort of unstoppable “doomsday weapon” right out of Dr. Strangelove, and a means to circumvent slowly improving US missile defences, which are designed to intercept ballistic missiles – rockets that arc high into space – and would be useless against this kind of weapon. Strategically, given how thin those US defences really are, with some chance of thwarting a limited attack from, say, North Korea (and even that would be dicey), but no hope whatever of blunting the sort of attack that would rain down from Russia’s existing arsenal, a weapon like Skyfall is utterly unnecessary. Sadly, Putin appears not to believe this. He seems to think that the thin-screen anti-ballistic missile defences being deployed by the Americans are meant to neuter the nuclear deterrent of Mother Russia, which, of course, is an escalation that can’t go unanswered.
So here we are back up to our necks in the nutty logic of Cold War deterrence theory, with weapons being developed not on the basis of actual enemy capabilities, but presumed enemy intent. This is a road that leads straight to Hell in a hand-basket.
What’s really terrifying about Skyfall isn’t so much its potential thermo-nuclear destructive power as the technical nature of the weapon itself, how it goes about its business, which makes even ICBMs decked out with multiple warheads seem blandly conventional. A cruise missile with nuclear propulsion is an absolutely horrifying thing, both practically and psychologically. We know just how horrifying, down to precise detail, because the Americans contemplated such a weapon themselves almost six decades ago, under an initiative dubbed Project Pluto, and the result was, well, so immoral that you go insane.
To begin with, making any sort of nuclear reactor that flies is of course an inherently risky thing. New flying machines need to be tested, and in tests of such an exotic new technology a few prototypes, perhaps many, can be expected to crash, with predictably unpleasant consequences. Once deployed, others will crash during ongoing operations as a statistical inevitability (even “use once” missiles need periodic re-testing and recertification, requiring some to be expended in tests). Moreover, the sort of missile contemplated by the Russian Skyfall project needs an especially wicked variety of reactor, one that’s inevitably dangerous even if it doesn’t crash, owing to the way it functions – the propulsion of any nuclear-powered flying machine pretty much has to work on the “ramjet” principle, and that’s a rather nasty thing when mated to atomic energy.
A ramjet is just what it sounds like – it’s a jet engine that works by ramming vast quantities of air into the front end at extremely high speed. Some sort of auxiliary propulsion, typically rocket boost, is needed to get up to the required speed to begin with, but once that velocity is reached, the air simply enters the engine mouth, gets compressed by flowing around a conical intake center-body or otherwise entering a narrowing chamber, is super-heated, then blasts out the back, and there you have it, high supersonic/hypersonic propulsion. Ramjets don’t even have moving parts. The sheer velocity of the incoming air as it squeezes into the engine’s insides takes care of the compression, and then all you have to do is dump some jet fuel in, light it, and you’re off to the races with enormous propulsive force. All modern attempts to develop hypersonic missiles rely on ramjets, or more precisely, “scramjets” – super-combustion ramjets.

Ramjets are simple, but traditionally still need jet fuel, and that means that range and endurance must have an upper limit. But what if you didn’t use jet fuel to heat the air? What if extreme heat filled the inner workings of the engine by way of a nuclear reactor? Why, then there would be no limit! In theory the thing would be able to run for years and years! Of course, in order to get all that heat from the nuclear reaction into the engine chambers, the reactors would themselves have to be, well let’s just come out and say it, completely unshielded. Which is to say, scorchingly radioactive. The materials science involved is mind-bogglingly sophisticated, but what you end up with is a reactor contained within the machine that is, essentially, running out in the open, emanating incredible heat, and this, of course, renders the air that enters it instantly radioactive too. It follows, then, that merely by flying, a nuclear ramjet is spewing dangerous efflux all over the place as it tears along, merrily expelling superheated radioactive air at high velocity.
Under Pluto, the Americans actually ran a couple of prototype engines on test rigs out in the desert, and the Vought company was tagged to design the airframe. What emerged on paper was the “SLAM” (for “Supersonic Low Altitude Missile”), and it was something that even the most pessimistic science fiction writer could never have imagined in his worst dystopian fever dreams. Get a load of this:



Just look at this monster. It’s evil. SLAM was going to be 90 feet long, and weigh 30 tons. Instead of a warhead, it was going to have a bomb bay, holding up to around two dozen thermonuclear weapons. After launch, it would climb to altitude under the power of rocket boosters, and reach a speed of Mach 4 or so, at which point the ramjet would function to keep it orbiting in big, lazy figure-eights until commanded to attack. Then it would descend to a very low altitude, only 500-1,000 feet, and tear-ass across the landscape at velocities still approaching Mach 3.5 (incredible given the increased density of the air at low altitude), navigating by an advanced form of low altitude radar terrain contour mapping called TERCOM (a version of which is used in modern US cruise missiles), spewing radiation all the way. As it roared over the Soviet countryside, dropping its warheads periodically as it overflew selected targets, its supersonic shock wave alone would kill anybody out in the open, and flatten any non-hardened buildings, before the missile sprinkled everything in passing with radioactive waste. Once it was out of bombs, it would navigate to one last target and slam into it at over 2,000 MPH, creating a small nuclear wasteland as a parting gesture.

Bear in mind, this was the early 1960s. The offspring of Project Pluto would have been as gob-smackingly advanced as they were abominable.
For once, the Generals and their mad scientists couldn’t go there. They took a look at what they’d wrought, blanched, and dropped the whole project down the memory hole, never to be spoken of again. The new Inter-Continental Ballistic Missiles would do just fine. No need for this appalling, radiation-spewing, death-dealing bastard of a missile to ever see the light of day.
This is the technology that Putin seems intent on reviving, and that’s a bad idea not just on general principles, but for safety reasons which by now should be all too obvious. It’s said that so far, the program has experienced numerous failures, the latest being the most catastrophic. It seems naive to imagine that Vlad the Impaler over there in Moscow will quit just because it’s so awful and dangerous; but maybe the technical challenges will prove insurmountable. Maybe not.
If only we could use all this human genius for good, instead of evil.