two and a small payload. The demands of being a human-rated vehicle, with instrumentation, environmental control systems and safety equipment, made the X-30 larger, heavier, and more expensive than required for a technology demonstrator. The X-30 program was terminated amid budget cuts and technical concerns in 1993. Legacy A more modest hypersonic program culminated in the uncrewed X-43 "Hyper-X". A detailed, one-third scale (50-foot long) mockup of the X-30 was built by engineering students at Mississippi State University's Raspet Flight Research Lab in Starkville, Mississippi. It is on display at the Aviation Challenge campus of the U.S. Space & Rocket Center in Huntsville, Alabama. Design The original concept was for a conical nose, this evolved (after 1987?) to a flat shovel shape. The X-30 configuration integrated engine and fuselage. The shovel-shaped forward fuselage generated a shock wave to compress air before it entered the engine. The aft fuselage formed an integrated nozzle to expand the exhaust. The engine between was a scramjet. At the time,, no scramjet engine was close to operational. The aerodynamic configuration was an example of a waverider. Most of the lift was generated by the fuselage by compression lift. The "wings" were small fins providing trim and control. This configuration was efficient for high-speed flight, but would have made takeoff, landing and slow-speed flight difficult. Temperatures on the airframe were expected to be 980 °C (1800 °F) over a large part of the surface, with maxima of more than 1650 °C (3000 °F) on the leading edges and portions of the engine. This required the development of high temperature lightweight materials, including alloys of titanium and aluminum known as gamma and alpha titanium aluminide, advanced carbon/carbon composites, and titanium metal matrix composite (TMC) with silicon carbide fibers. Titanium matrix composites were used by McDonnell Douglas to create a representative fuselage section called "Task D". The Task D test article was four feet high by eight feet wide by eight feet long. A carbon/epoxy cryogenic hydrogen tank was integrated with the fuselage section and the whole assembly, including volatile and combustible hydrogen, was successfully tested with mechanical loads and a temperature of 820 °C (1500 °F) in 1992, just before program cancellation. Specifications (X-30 as designed) Design and materials legacy See also References American X-Vehicles Air Force History of the NASP(pdf) External links Video Aero-Space Plane: Flexible Access to Space (NASA) 4 min Spaceplanes Proposed reusable launch