A rifle bullet out of an M-16 goes 2700 feet per second. We're going to go 3400 feet per second. That's two thirds of a mile every second, and when you look at that vehicle, it doesn't look like it could go that fast. It's just made out of fabric, with some epoxy glued to it to keep it stiff. It's got plastic windows, and it's going faster than a bullet. There's some risk involved there!
History's already been made by the flights they've done before, but this one will mark the race as won. Good luck to the Scaled Composites folks! (And to those who are interested in it, I cannot recommend Discovery's 'Black Sky' documentary enough.)