The SR-71 is amazing in many ways. It can't start it's own engines, they are started one at a time by a huge generator that drives under each wing. Adding to what you said about the skin of the plane, what I heard is that the skin isn't sealed until it's flying... that the SR takes off with a minimal fuel load, because it literally leaks fuel, and then gets refueled immediately. It's no wonder people speculate there was other-worldly inspiration.