Take, for example, the hidden history of flying saucers. In the late 1950s, it seems, the U.S. Air Force really was working on Project 1794 to build a supersonic saucer. The first test of the VZ-9 Avrocar took place on Nov. 12, 1959. Hopes of a lean, mean, and circular fighting machine were high, but the prototypes never met the military's standards. Instead of rising to an altitude of 100,000 feet, it got closer to 5,000. It never hit the right speed, either, as its shape proved pretty unstable. The top-secret project was cancelled by 1961, but visions of flying saucers have persisted.