X-planes: The Next Eight: X-24 through the X-38

X (experimental) aircraft and spacecraft were built by aviation companies but were flown and maintained by test pilots from NASA (or its predecessor, NACA), and the military. These planes, the X-24 through the X-38, cover the period from 1959 through 2002. Some were used to explore technologies that would later be used on the Space Shuttle. Others pushed the envelope in terms of control and flight surfaces, knowledge that would be used on fighter aircraft as well as drones.