NASA believes it has designed a space plane that will set a new speed record for aircraft. Unveiled in April 2001, the X-43A space plane is expected to break Mach 7 and, in later tests, Mach 10. If its successful, the X-43A will break the speed record of Mach 6.7, set in October 1967 by an X-15 space plane.

Photo courtesy NASA
The X-43A will be the first aircraft to reach hypersonic speeds using an air-breathing engine.

What sets the X-43A apart from other rocket-powered aircraft is that it is powered by a scramjet engine. Instead of using onboard oxygen to combust the hydrogen fuel, the scramjet scoops up oxygen as it travels through the atmosphere. By eliminating the need for onboard oxygen, cutting the weight of the spacecraft, the X-43A could lead to cheaper Earth-to-orbit space travel.

The May 2001 test of the $185-million X-43A prototype is only a very early assessment the planes experimental engines. NASA doesn't expect to use them for space travel for at least another 20 years. In this edition of How Stuff WILL Work, you'll get a sneak peek at the X-43As abilities and learn about its air-breathing engine.