The sled was awesome. Many years back I was attending an advanced training course with other service members and in the course of affairs we received an informal presentation about the development of the aircraft in terms even a chopper pilot could grasp. High points: Washington wanted a platform that could renew what the U2 had been doing w/o getting shot down. Kelly Johnson responded with something to the effect of "Give me the fuel and I'll make the plane." Point being the sled's fuel is not a splashy liquid as most assume. It's gooey. Reason? The aiirframe is hot when it's cruising M2+. They made the skin out of titanium for the same reason, and it is a metal not easy to form due to physical properties. Thus was the concept of bead hammering invented. That's my term and may be incorrect, remember, I'm a rotor head not a space cadet. Short version? They used a stream of glass beads from a nozzle not unlike a sand blaster, a form, and quite literally hammered the metal into submission.
We had the conversation because at that point the class was studying structural issues related to design and failure.
20 years later I routinely conversed with Blackbird pilots as they flitted around on missions in and around the Caribbean. Dayum, them things are faster than Wild Bill....
