Inside the Air Force's 13,000-MPH Hypersonic Plane

An unmanned aircraft that can travel at a breakneck pace 20 times the speed of sound will take off Wednesday from an Air Force base in California for a test flight.

Read more: http://www.foxnews.com/slideshow/scitech/2011/08/10/experimental-military-plane-goes-mach-20/#ixzz1Udd54WU0