Wednesday, September 29, 2004

Great weapons that could've been, Part I:

The Atomic 'Flying Crowbar’ of Death

Imagine, if you will, a nuclear cruise missile. Not a conventional cruise missile such as we’ve all seen on TV, armed with a nuclear warhead -- but one the size of a railroad locomotive, powered by a nuclear ramjet engine, with a bomb bay holding dozens of nuclear weapons. Imagine it flying just above treetop level at 3.5 times the speed of sound, invulnerable to all defenses, tossing out nuclear bombs on its way along its 100,000 mile operating range.

That was the nifty idea of the US weapon designers in the 1950s who conceived Project Pluto. Their objective: to find a better way to deliver nuclear warheads upon targets in the Soviet Union, when the main means of doing so was by manned bombers that were costly to maintain, operated from vulnerable bases, and could be shot down.

It was the dawn of the Atomic Age. Nuclear power would soon make electricity too cheap to meter and was already powering submarines under the arctic, while Project Orion was developing plans to launch atomic powered space ships -- real ships, 16 stories high, weighing 10,000 tons, crew of 150 -- to Mars and Saturn. So why not an atomic powered Supersonic Low Altitude Missile (SLAM)?

The atomic SLAM would fly from a safe base in the US, below radar and far faster than any aircraft that might try to intercept it, with the destructive power of a dozen bombers. Just the power of the shock wave coming from Mach 3.5 flight at treetop level, together with the radiation spewed from the unshielded reactor (not a flaw, a feature!) would let it destroy pretty much everything in a target country merely by flying back and forth over it, without even using its bombs.

Would it have worked? Sure thing! The engines were tested and the design was so solid and robust – “about as durable as a bucket of rocks” – that it was dubbed the “the flying crowbar”. The technology was great and its creators were proud of it.

So why has nobody ever seen this wonder weapon fly? Well, while the technology of the SLAM was solid there were certain practical problems in implementing it.

To reach its target it was expected to have to fly over friendly countries, flattening and irradiating them in a way they might not appreciate. Should the thing go astray a thousand miles into its flight, there was no absolutely sure way to correct its course or turn it “off” – and you really want to have a sure way to turn a thing like this off before it goes 99,000 miles in the wrong direction. Even the military was getting the idea that it isn't a good thing to go around spewing radiation into the open world. And the Defense and State Departments came to deem the project “too provocative”, fearing that if the U.S. deployed such a weapon the Soviets would feel forced to develop the same nasty unstoppable thing – and did we really want that?

But the capper was that the designers couldn’t figure out a way to test it. The original intention was to have test flights over the Nevada nuclear testing grounds – but suppose a flight decided on its own to head for Las Vegas, or Los Angeles, or Chicago? Or perhaps Las Vegas, Los Angeles and Chicago? The designers never found a satisfactory answer.

By the early 1960s ballistic missiles had progressed far more than previously anticipated, giving the military other options, and the nuclear test ban treaty was signed to ban open air releases of radiation. Projects Pluto and Orion were both ended, and the SLAM was relegated to remain forever on the drawing board, next to the 1970 Mars Mission of Project Orion.

But it’s fun to remember what wonders the Atomic Age once promised.

References: Air & Space Magazine, Department of Energy (pdf),, Directory of U.S. Military Rockets and Missiles