This photograph captures the North American X-15, a rocket-powered research aircraft jointly operated by the U.S. Air Force, NASA, and the U.S. Navy during the late 1950s and 1960s. Capable of reaching speeds above Mach 6 and altitudes exceeding 350,000 feet -- effectively the edge of space -- the X-15 provided critical aerodynamic, thermal, and physiological data that directly informed the design of later spacecraft, including the Space Shuttle. Its distinctive skid landing gear, used for touchdowns on dry lakebeds, and wedge-shaped tail fin made it one of the most recognizable experimental aircraft of the twentieth century. Project: 218470