Popular Mechanics (South Africa)
The most dangerous weapon never made
LAST WINTER, in 2019, a small nuclear reactor exploded on a military testing site in Russia, killing seven people and causing a brief spike in radioactivity in two nearby cities. Even now, the details are still scarce; Russia’s nuclear agency blamed tests concerning ‘isotopic sources of fuel on a liquid propulsion unit’. But evidence suggests that the mysterious accident was related to Russia’s development of the Burevestnik, a nuclear-powered cruise missile that would offer a nearly unlimited range, allowing it to fly for much longer than conventionally powered cruise missiles that exist already.
Not long after the explosion, US President Donald Trump revealed in a tweet that the United States has ‘similar, though more advanced technology’ to the Burevestnik, sometimes referred to as ‘Skyfall’. The problem? The US already looked into nuclear-powered cruise missiles more than 50 years ago – and rejected them as completely impractical.
Back in the 1950s and ’60s, the US Air Force wanted a third weapon in its arsenal in addition to its intercontinental ballistic missiles and strategic bombers for delivering retaliatory strikes against the Soviet Union in the event of nuclear war. Enter the Supersonic Low Altitude Missile, or SLAM, which the Pentagon hoped to have ready for use by 1965. Had the US actually built this thing, it would have been the
most dangerous nuke ever made – and possibly the last.
Aerospace giant Convair designed SLAM (also known as the ‘Big Stick’) as an air-breathing, low-flying cruise missile. A rocket booster would launch it into the air and send it to speeds where its nuclear-powered ramjet would kick in. Once activated, the engine would give SLAM a top speed of Mach 3.5. The missile would then cruise for days or even weeks, flying unusually low for a missile of its time – just 300 m – to avoid being tracked by enemy radar. The supersonic shock wave was projected to leave a trail of devastation, flattening forests and buildings, and killing anyone in the missile’s flight path.
Despite being advertised as a missile, SLAM was actually more like an unmanned bomber. Instead of a single warhead, it carried up to 26 hydrogen bombs, each hundreds of times more powerful than the bombs that the US dropped on Hiroshima and Nagasaki in 1945. SLAM could fly a predetermined route over an enemy country or even continent, dropping H-bombs on destinations below. Once the Big Stick was out of bombs, the weapon would fly one last suicide mission, running into a final target that would shower the target zone with lethal radioactivity.
Of course, the US never built SLAM, because it was far too dangerous to even test (although most individual components, including the reactor, were successfully prototyped). The military scrapped the weapon in 1964 amid concerns about its cost-effectiveness and viability. While the hazardous levels of radioactivity unleashed by the nuclear engine were a big plus in some apocalyptic wartime scenarios, the weapon couldn’t be tested in the skies over the US.
SLAM was also supplanted by intercontinental ballistic missiles, which, for all their flaws, could deliver a thermonuclear warhead against a target in Russia in half an hour.
SLAM was unofficially the worst nuclear weapon ever developed. And whatever Russia was really testing last winter in the Arctic, it’s likely something that should have remained an unused relic of the Cold War, just like our Big Stick.