Aerospace researchers have been trying for decades to build engines that can send planes and projectiles flying at hypersonic speeds -- 3,600 miles per hour, or more. So far, they haven't had much luck. But one of the most promising hypersonic projects to come out of government labs yet is looking better and better. The X-51 hypersonic cruise missile just passed its critical design review, and fired its engine for the first time. Things appear to be on track for test flights in 2009.
White Sands Missile Range is probably going to be too small for this one.