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Hyper-X arrives at Dryden
Public Affairs Specialist The world's first hypersonic air-breathing free-flight vehicle is no longer just a paper plane. The first of three experimental vehicles, designated X-43A, arrived Oct. 13 at Dryden. When the X-43 vehicles fly, it will be the culmination of over 20 years of scramjet (supersonic combustible ramjet) research and the first time a non-rocket engine has powered vehicles at hypersonic speeds. Hypersonic speed means above Mach 5, which is equivalent to about one-mile-per-second, or 3,600 miles per hour at sea level. The highest speed reached by NASA's rocket-powered X-15 was Mach 6.7. Currently, NASA's SR-71 is the world's fastest air-breathing aircraft soaring slightly above Mach 3, or three times the speed of sound. A ramjet engine operates by subsonic combustion of fuel in a stream of air that is compressed by the forward speed of the aircraft itself at a speed less than the speed of sound. The scramjet is a supersonic-combustion ramjet in which the airflow through the whole engine remains supersonic, or speeds from one to five times the speed of sound. "This is high-risk technology. It's exactly the type of flight research that NASA's Office of Aerospace Technology should be doing, " said Joel Sitz, Dryden's X-43A Project Manager. "People have dreamed of cruising at hypersonic speeds since before the twentieth century. NASA working with industry must answer the mail on developing a feasible, efficient design." Unlike a rocket that must carry its own oxygen for combustion, an air-breathing aircraft scoops air from the atmosphere, making it lighter and enabling it to carry more cargo/payload than rocket-powered propulsion vehicles. The X-43 will use the body of the aircraft itself to form critical elements of the engine with the forebody acting as the intake for the airflow and using the aft section as the nozzle. Built by Micro Craft, Inc., Tullahoma, Tenn., for NASA's Hyper-X program, the 12-foot-long, unpiloted X-43 vehicles will significantly expand the boundaries of air-breathing aircraft. Three flights are plannedótwo at Mach 7 and one at Mach 10. The flight tests will be conducted within the Western Test Range off the coast of southern California. Each Hyper-X vehicle will ride atop a booster rocket from Orbital Sciences Corp., Dulles, Va., and both will be air-launched by Dryden's B-52 airplane. After being launched from the B-52, the X-43 will separate from the rocket at a predetermined altitude and velocity, then fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments before it impacts into the Pacific Ocean. NASA's Langley Research Center, Hampton, Va., manages the multi-year Hyper-X program and is also where the X-43's engineóscramjetóis being wind-tunnel tested. Dryden is responsible for vehicle fabrication and flight tests. The Hyper-X research vehicle, X-43A, is scheduled to fly in next year. |
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Responsible NASA Official: John Childress For questions, contact: Dryden Web Group Page Curator:WD-Team Modified: October 28, 1999 |
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