A repost from August 2016.
From The National Interest:
The US Military's Ultimate Cold War Missile Could Have Been a Flying Chernobyl
It was the perfect airborne death machine—a supersonic drone of nearly unlimited range, loaded with hydrogen bombs zooming around Earth at more than 2,500 miles per hour.
To the engineers who worked on its development, it was “technically sweet” and the high point of their careers.
Developed between 1957 and 1964, the Supersonic Low Altitude Missile was one of the craziest, deadliest nuclear weapons systems ever pursued.
The locomotive-sized cruise missile would loiter at high altitudes above the Soviet Union, before dropping down to treetop level and roaring across enemy territory at Mach 3. Then it would lob nuclear bombs at everything in its path.
Were it ever completed, the missile likely would have worked. But the success of several experimental designs turned out to be the project’s ultimate doom.
The SLAM missile also overcame several interesting engineering challenges. During the 1950s, the vast power and endurance of nuclear energy seemed ideal for powering fast, long-range rockets and airplanes. In theory, a nuclear-powered airplane could stay aloft for days, or fly at incredible speeds without refueling.
But nuclear reactors are heavy. The shielding required to keep a flight crew safe from radiation makes building a nuclear-powered flying machine challenging, to say the least.
From 1956 to 1957, the Air Force experimented with an airborne reactor as part of its Nuclear Airborne Propulsion program. The reactor took up one whole bomb bay of a modified B-36 bomber while the crew sat in a 12-ton lead and rubber-shielded cockpit.
While the nuclear aircraft program wrestled with complicated plumbing and tons of shielding, the SLAM project dispensed with the crew and pursued a simple but scary idea—the nuclear ramjet.
A ramjet is a jet engine that moves so fast, the air entering its combustion chamber becomes hot and dense enough to ignite fuel. The resulting explosion of hot gas pushes the ramjet—and its attached vehicle—to supersonic or even hypersonic speeds....MUCH MORE
