In 1982 the US government initiated a top secret research program known as Copper Canyon, to investigate the possibility of a single stage-to-orbit airplane which could take off and land horizontally. In 1990 the X-30 National Aero-Space Plane was developed by MacDonald Douglas, Rockwell International and General Dynamics in an attempt to prove that thermal Dynamics in an attempt to prove that thermal dynamics have a direct effect on the speed at which an aircraft can travel. The buzz word in the space industry now is tourism. Private companies have moved into space research, with the philosophy that the best way to extend man's reach into space is to promote it as a tourist destination.