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
