X-33 aircraft. Technician placing a model of the X-33 aircraft in a helium wind tunnel. The X-33 is a prototype reusable launch vehicle (RLV). It was designed to test technologies for the VentureStar, a spaceship that would drastically reduce the cost of putting payloads into space. This helium tunnel allows aircraft to be tested at speeds of over 20 times the speed of sound (Mach 20). The X-33 project, a collaboration between NASA and Lockheed Martin, USA, was cancelled in March 2001. Photographed at the NASA Langley Research Center, Virginia.