I've was in Farnburough England at the air show when one blew an engine during a flyby and had to make an emergency landing. They parked it in an open space and after armed marines surrounded it, they opened it up to the public. I got to spend about ten minutes talking to one of the pilots who was still in his space suit. The one thing I remember the most was how the ti surface was partially melted and you could see it cooling.

As for the SR-72. Lockheed had better come up with a timeline that's a hell of a lot better than 2030. Musk can invent something similar in 15 months not 15 years.