According to the Russian Ministry of Defense, the explosion that took place on August 8th at a remote base concerned the propulsion system of a liquid-fuel rocket engine and no dangerous substances were released. But within minutes, the nearby city of Severodvinsk reported a spike in radiation (in a report that has subsequently been removed from the city’s public information site). Additionally, it was widely reported that a village near the base would be evacuated … before that evacuation was officially denied. And The Moscow Times reported that, in addition to the two immediate deaths in the explosion, a hospital in the Arkhangelsk region received three injured men who were “naked and wrapped in translucent plastic bags.” Subsequent tests indicated that the doctors who treated those men had signs of exposure to the by-products of Uranium-235.
All of which leads to the question — just what has Russia been doing up there? For an answer, it may be necessary to go back to the future … of nuclear rockets.
In a sense, nuclear and rockets have been a match from day one. Germany’s V2 missiles were regarded as a “terror weapon” in World War II in part because they were singularly ineffective at causing damage to important targets. With less than perfect guidance systems and a capacity that matched just one large bomb carried by a bomber, they were an inefficient way to deliver real damage to military targets. However, the ballistic arc of the weapon made it unstoppable by fighter aircraft or anti-aircraft weaponry, and the imperfections of the guidance meant that it could come screaming down anywhere at almost any time. Pair that capability with a nuclear warhead … and the combination was the weapon that would define the post World War II world.
But almost from the beginning, there have been ideas about doing more than pairing a chemically-propelled rocket with a nuclear payload. If a nuclear weapon was a huge “upgrade” to the destructive power a missile might bring, could nuclear power deliver a similar boost to a rocket’s propulsion system? There are very good reasons to think that what happened at Arkhangelsk is part of a program to answer that question, and to turn engineering speculation that goes back more than sixty years into astounding — and terrifying — reality.
To see what’s happening in northern Russia in 2019 requires digging into some classified information. From the United States. In the 1960s. And in particular, it requires looking at three projects named Pluto, Rover, and Orion.
Project Pluto — the missile that flies forever
Months before the explosion, Russia moved resources involved in their Arkhangelsk away from the sea, into an isolated area, and under the cover of some new buildings, all of which are signs that they didn’t want prying international eyes to catch a glimpse of what they’re working on. Most speculation concerning what’s happening at Arkhangelsk centers on one of the “super weapons” that’s been part of the parade of such claims that Vladimir Putin has trotted out over the last year. In particular, ideas have centered on a missile that, in the West, has gained the codename of “Skyfall.” Because yes, of course military analysts watch James Bond movies.
Nuclear Ramjet test platform
Skyfall is, as a thousand news sources have stated, supposed to be “a nuclear-powered cruise missile.” But what does that mean? Chemical engines are quite capable of creating “hypersonic” weapons like the ones that have been at the center of another Putin brag. Why use nuclear power to drive a missile?
The answer to that goes back to a project that began in 1957 when the U.S. Air Force and the Atomic Energy Commission teamed up to create a nuclear ramjet. A ramjet is a a very special form of jet engine that uses that engine’s own speed to help compress the incoming air. In theory (and more limited practice) they’re capable of astounding performance and speed—like six times the speed of sound or even higher—except that they have problems.
First, the ramjet effect can’t really kick in until the engine is traveling at high speed, so a ramjet-powered plane or missile needs some other system to get going. In fact, ramjets don’t really come into their own until they reach a speed somewhere over twice the speed of sound, so that boost has to be a big one. The second thing is that while a ramjet is pretty efficient compared to other jet systems at this speed, it’s a long way from perfect. The compressor inside the ramjet requires more and more power the faster it goes, putting limits on both that top speed and the range of a ramjet-powered vehicle.
But that 1957 project, a project that eventually operated under the code name “Project Pluto,” had a an answer for the ramjet’s problems. The idea was to create a nuclear-powered ramjet that would ride as the second stage on an missile. The first stage would use an ordinary chemical engine to get the ramjet up to speed. Then once the nuclear ramjet took over the missile could fly … forever. Or close to it.
Imagine a missile that’s soaring along alarmingly close to the ground at nearly 5,000 miles per hour, constantly changing course, constantly in motion, able to reach any location on demand. Now imagine a few thousand of them; a swarm of nuclear-powered hornets boiling around the Earth, each of them carrying a nuclear sting.
Project Pluto actually made good progress toward this goal, achieving several good tests of the proposed engine, before the notable peaceniks at the Pentagon decided that when it came to terror weapons … this might be going several steps too far. Enthusiasm for the project sputtered, and it was cancelled by 1964.
Project Rover — Putting Men on Mars by 1978
But Skyfall isn’t the only nuclear rocketry project on Putin’s plate. Last November, Tass ran images of a proposed Russian nuclear rocket designed to carry both probes and human beings into space. These images came as Russia’s space agency, Roscosmos, admitted that the new generation of American rockets were eating their lunch. While Russia continues to hold a lock on manned flights to the ISS, the greatly reduced cost to orbit provided by companies like SpaceX, Rocket Lab, and others has put the writing on the wall for Russia’s space-launch cash cow. The launch systems currently in use, including those used to send people to orbit, are well tested because they’re old. Roscomos has been admitting for several years now that their current selection of Soyuz-based rockets is simply noncompetitive and getting less so by the day.
Technicians at work on a Kiwi nuclear rocket test
Rather than trying to do an update that would put their rockets on par with SpaceX, Blue Origin, or other upcoming systems, Roscosmos has instead claimed they will “leapfrog” the U.S. providers by using a technology that’s known to be much more efficient than any chemical rocket—nuclear thermal rockets.
Strangely enough, that idea also directs attention right back to 1955. That’s when the United States initiated a series of proposals that under the name Project Rover. Eventually the project would acquire a series of other handles, but all of them were centered around the same project—creating a rocket that used a nuclear reactor to heat a propellant far more efficiently than any chemical reaction. The on-paper results were so good that both the Air Force and NASA loved the idea.
And this idea went way beyond paper. Between 1955 and 1972, a whole series of test reactors were built. Like Pluto, the first idea was to build a reactor that could perch on the second stage of an ICBM, but the reactors, and the goals, of Rover expanded rapidly. The tests were actually very successful, and showed that nuclear thermal rocket engines lived up to their potential. In fact, the tests were so successful, that the goals became increasingly ambitious.
As tests progressed from Rover to Kiwi to NERVA, NASA worked out a design that would plant one of these nuclear boosters on top of the already might Saturn V. With that design, they plotted out a series of missions that included getting men on Mars … by 1978. In one proposal, the Saturn V / NERVA combination was even slated to take human beings on the kind of Solar System “grand tour” that was followed by the Voyager probes. NASA was convinced that the nuclear engines being created by this project were the real tickets to opening space for exploration.
Except … in the wake of the Apollo landings, NASA’s budget came under heavy scrutiny. Richard Nixon, despite getting his name on the plaque, was no fan of the program and pushed for cuts. Instead he pushed for money to be sent to a supersonic plane program that had already been awarded to a Boeing design called the 2707. Both sides lobbed massive public attacks on the other, including planting plenty of stories in the media and recruiting environmental groups to assist in the cross-fire. Finally, in a mutual snit fit of “you killed my program, so I’m getting yours” it all collapsed. Anyone looking for a moment when a Jetson’s-style future really died might want to check out 1972, when both supersonic transport planes and nuclear rockets to Mars disappeared in budgetary smoke.
Then you can ponder whether that deserves a tear, or a huge sigh of relief.
Project Orion — to the stars, by skyscraper
If the Rover / Kiwi / Phoebus / Peewee / NERVA-style reactor-rocket promised to open up the solar system, NASA’s plans for sending humans zipping around on Saturn plus Nuke looked like child’s play next to the other nuclear rocket proposal from the same time period. Because that one involved sending human beings to the stars in a ship bigger than Macy’s.
The basic ideas behind what would become Project Orion go back to the 1880s, when scientists (Russian scientists, actually) worked out that you don’t need a steady thrust to drive a rocket. You can do it with a series of explosions. Instead of a rocket, what you need is something like a vending machine that shoots out a stream of carefully timed soda cans. Each of which is actually a bomb. This led to some delightfully steampunkish designs in which a space vehicle — you can’t really call it a rocket — was propelled by a kind of backward facing cannon mounted on a shock absorber to give the potential occupants a somewhat smoothed out ride. Mathematically it works, practically, it never happened, though there are several nice fictional stories built around the idea.
Almost from the beginning, scientists at Los Alamos saw that replacing those little chemical explosions with nuclear explosions could make for one helluva space ship. In 1958, physicists Freeman Dyson and Ted Taylor took this up as Project Orion. And they did not think small.
The math alone was enough to show why the project gained immediate attention. Orion offered a mixture of high thrust and high efficiency that couldn’t be matched by any kind of rocket, not even the nuclear-based ones in Rover. Orion didn’t just offer more power and efficiency than any rocket on the drawing board, it offered more power than any rocket that could be imagined. Dyson took the idea to it’s limits, working out that a Orion-based system could actually achieve an appreciable percentage of the speed of light. It was, and still is, the only such system that we know how to build.
The problem is that Dyson’s city-block sized ship would have been powered by nuclear weapons. A “smaller” design that would have driven an 8 million ton vehicle around the Solar System dropping in on Jupiter and Saturn, was based on just over 1,000 three kiloton bombs. External nuclear propulsion was the most efficient and powerful system ever proposed … and it’s external nuclear propulsion.
Unlike the other systems, Orion never really left the paper stage, at least when it came to nuclear-explosions as a means of propulsion. The idea of creating a ship whose “engine” was enough nuclear weapons to spark a new arms race never thrilled anyone who looked at more than the numbers, and the first Test Bad Treaty in 1963 pretty much wrote the final end to the project.
So what’s going on at Arkhangelsk
Well that’s … a really good question. Because none of the proposals above really fit the evidence.
A Project Pluto style system is what most analysts seem to be thinking when they talk about Skyfall, but the Russian announcements on the accident indicate that it has to do with a liquid-propellant rocket system, not a ramjet. Though, no shock here, the Russians could be lying about that. Also, testing a ramjet system on the ground is tough. Project Pluto included a facility with 25 miles of pipe used to fire high speed air down the gullet of the test engines. There’s no sign of anything like that in the relatively small facilities that have been constructed in Arkhangelsk.
If the Russians are taking Project Rover back to its ICBM roots, that might satisfy the requirements, because those systems did involve driving a liquid propellant through the mini-reactor. The U.S. version of those tests included some genuinely massive facilities, including a special electric railroad that slowly hauled the rockets into a separate facility for test fires, and hauled them back for postmortems. There’s also no sign of anything like that at Arkhangelsk. On the other hand, those tests went well and the information has since been made public, so Russia might be thinking “screw the safety, just build it.”
And finally, Orion was designed to blow up by design, so maybe … no. No even Putin would be that crazy.
Neither Orion or Rover / NERVA was ever actually intended to operate in the atmosphere. In both cases, scientists assumed that the system would be lofted into space using engines that were a little more life-on-Earth-friendly. Of all of the big nuclear rocket programs, only Pluto was really meant for the kind of in-atmosphere design that would match the description of a “nuclear cruise missile.”
If that is what’s being built in Arkhangelsk, then the goal is probably the same as it was in the 1960s — a missile that can fly non-stop for months, skimming the Earth at thousands of miles an hour. And in the fifty-plus years since Pluto was cancelled because it was “provocative” and “unstoppable” … neither of those things have changed.
