Phooey! Bet it doesn't get as good mileage as my Honda Insight! (69.6 mpg commute...)

http://www.boston.com/dailynews/108/nation/NASA_unveils_new_plane_designe:.shtml

NASA unveils new plane designed to be world's fastest

By Andrew Bridges, Associated Press, 4/18/2001 20:17

EDWARDS AIR FORCE BASE, Calif. (AP) NASA on Wednesday unveiled a futuristic aircraft designed to accelerate through the atmosphere at speeds up to 7,200 mph to become the world's fastest plane.

The National Aeronautics and Space Administration's first unpiloted X-43A will make its maiden flight in mid-May, flying under its own power for just 10 seconds and about 17 miles before crashing into the Pacific Ocean.

NASA said the plane would be designed to fly at up to 10 times the speed of sound. Mach 1 is the speed of sound, which varies by altitude and is about 750 mph at sea level.

Two other X-43As will fly after the initial test at six-month intervals. If successful, the 12-foot-long, surfboard-shaped planes will smash the speed record of Mach 6.7, set by an X-15 in October 1967.

Unlike the rocket-powered X-15, the X-43A has an air-breathing engine: it carries hydrogen for fuel, but must scoop oxygen out of the atmosphere to combust it. Conventional rockets carry both the hydrogen and oxidant.

The $185 million project is purely experimental. Engineers will collect flight data needed to build future planes perhaps 200 feet in length. The first piloted prototypes may fly by 2025.

Backers of the technology say air-breathing hypersonic propulsion could help space travel. The X-43A, or Hyper-X, will probably never carry commercial passengers because of the high acceleration, heat generated by friction with the atmosphere and the difficulty of turning a plane at such high speeds.

None of the X-43As will be recovered from the ocean, officials said.

Currently, the fastest air-breathing aircraft is the SR-71 ''Blackbird,'' which cruises slightly faster than Mach 3. The X-43A would be the first air-breathing plane to go hypersonic, or faster than Mach 5.

The government has pursued the idea of routine hypersonic flight for four decades, including an abortive $2.4 billion effort begun under President Reagan to build a ''National Aero-Space Plane'' capable of zipping halfway around the globe in a few hours.

''The concept is pretty simple, it's just that no one can seem to make it work,'' said Howard McCurdy, a professor of public affairs at American University.

Backers of the technology see air-breathing hypersonic propulsion as advantageous for improving access to space. Eliminating the need to carry oxygen could cut the weight of a space-faring version of such a plane in half.

The X-43A requires a big boost before its specialized supersonic-combustion ramjet, or ''scramjet,'' engine can work. A scramjet engine only works when air flows through it at supersonic speeds.

To make sure the air goes through the engine fast enough during test flights, a B-52 will haul the X-43A to about 24,000 feet and release it. A booster rocket will ignite to accelerate the X-43A to its test speed and altitude of about 100,000 feet. The X-43A will then separate from the booster and fly west over the ocean.

-- Anonymous, April 19, 2001