Russia is getting a lot of attention lately for things like hypersonic missiles and nuclear doomsday weapons but all that is just old hat to the Pentagon. The United States has been working with doomsday weapons for years; we just never went around bragging about it.
Or blowing up our own nuclear reactors.
The Cold War was a pretty good time for America, especially where defense is concerned. Even though we may have thought of ourselves as trailing the Soviets with ridiculous things like "missile gaps," the truth was we were often further ahead than we thought. Hell, we were going to nuke the moon as a warning but decided the PR would be better if we landed on it instead. If the Russians wanted to impress us, they could have taken a photo next to our flag up there.
When it came to weapons, the U.S. had no equal. We built horrifying, terrifying, and downright unbelievable devices that were an excellent show of force at best and – at worst – absolutely batsh*t crazy. Project Pluto was one of the latter.
Simply put, Pluto was a cruise missile that flew at a low altitude with a nuclear payload. Sound pretty Cold War-level simple, right? The devil is in the details. The actual acronym for the weapon was SLAM – supersonic low altitude missile. This meant a giant missile that flew around below radar, around treetop height, faster than the speed of sound, so it could penetrate enemy territory without anyone seeing it or being prepared for what came next.
Which was about 16 hydrogen bombs dropping on Russian cities. But that's not all!
The SLAM Jet's ramjet engine.
The weapon isn't unique because of the number of weapons it carried. Intercontinental ballistic missiles, the weapons that would eventually make SLAM jets obsolete, carried multiple warheads that could be targeted at multiple cities. No, the unique part of the SLAM jet weapon is what it is. The missile is designed around a single, nuclear-powered jet engine which is sent aloft by rocket boosters but soon becomes indefinitely sustainable via the power of the nuclear jet engine's intake.
So, the weapon could drop its payload and then keep flying forever, creating sonic booms above the treetops, murdering anyone on the ground. The fact that the engine is just an unshielded nuclear reactor meant its exhaust would spew radioactive material all over any area unlucky enough to have it pass by overhead.