scambo1

We've been hearing about the "aerospace plane" since I was a kid. New York to Tokyo in 2 hours, etc. The problem was not metallurgy, but instead the tech to make it work, primarily figuring out how to light the scramjet at high mach speeds. We cleared that hurdle about 3.5 years ago, but in the intervening time, the plane went from being piloted to pilotless.