That's Mach 5 for those keeping score at home. Other impressive features: It runs on liquid hydrogen, it looks cool, the guy in charge of the project is named Mr. Bond. Downside: It won't be ready for the next 15-25 years.
Editorial note: Whoa! You've found a super-old post here on BuzzFeed, from an earlier era of the site. It doesn't really represent where we are anymore, and may in fact be totally broken, but we're leaving it up as a part of our early history.