 Imagine taking off from an airport runway flying at three to five times the speed of sound at altitudes of 20 miles or even higher. A few short hours after departure you come to a stop halfway around the world. Or maybe you took off from a runway and flew directly into orbit to work in space and then you return landing on a conventional airport runway. The National Aerospace plane will try to make both scenarios a reality. NASA and the Department of Defense have done research on hypersonic technology for many years. The NASP technology demonstrator will be a highly advanced X-plane, a new member of the elite special research aircraft that includes the X-1, which in 1947 was the first aircraft to break the speed of sound and fly supersonic. In the early 1960s the X-15 became one of the first manned hypersonic aircraft and reached speeds of Mach 7 or about 4,500 miles per hour. One of the key technological developments of the X-30 or NASP are in the propulsion area. An air-breathing hydrogen-fueled supersonic combustion ramjet engine or scramjet engine is now being developed for speeds from about Mach 7 to Mach 25. The engine uses the velocity of the vehicle to compress air as it is rammed into the intake. This compressed air is then mixed with gaseous hydrogen at this stage to generate high thrust. A development on which we will focus is materials. Here to speak on that is Matt Mellis. With the advent of the aerospace plane there's become a need for a lot of new material development. Beyond the shadow of a dot we need new materials and these new materials will most probably be composite materials, but instead of using a metal matrix-based composite we'll be using a metal matrix-based composite. Metal matrix being copper for instance. One of the big problems NASA is facing with the advent of the national aerospace plane deals with not only finding the right materials to use but in cooling them as well. We have to figure out some way of making a very strong material that's going to survive in a high temperature environment and what we're going to have to do is actively cool this material, by putting some kind of a cryogenic fluid behind it, gaseous hydrogen or liquid hydrogen which is very cold and the next is a good heat transfer medium to take heat away from the leading edge. So on one side of the material, on the inside of the wing for instance, there'll be a lot of coolant rushing through to cool the inside down and on the outside you'll have a very hot surface and that is why we need the high heat conductivity. For instance you look at fighter jets that travel Mach 1 or Mach 2 or even the Concord which goes up the Mach 2. You see that their wings are very narrow at the leading edges. The problem with that because the smaller the leading edge gets, the more difficult it is to cool and the hotter it gets because it's such a small point lying out there in the free stream that it gets very warm very quickly. The national aerospace plane is one of the projects being developed by NASA for future space use but we cannot expect it to do all of our work in space. The national aerospace plane being something that will possibly be able to supplement the shuttle fleet or maybe even replace it but obviously if you have an airplane that can take off from a runway and go to orbit with some people in it and go to the space station for instance or something like that obviously it would be capable of shuttle type operations. As far as payload goes I think moving big things like space station components or say for instance they want to go to Mars and they have to get some big boosters up there or something like that I don't see the national aerospace plane taking that kind of payload up there. The national aerospace plane is expected to yield a high payoff for the United States in the early 21st century with reduced space launch costs vastly reduced transit time on long-haul air routes major investments by private enterprise in commercial space ventures and sustained US preeminence in aeronautics with all of the social and economic benefits that accompany it.