Boeing X-40

The Boeing X-40, in its X-40A form the Experimental Space Maneuver Vehicle, was an American uncrewed spaceplane built by Boeing as a test article for landing technologies that would later be used on the larger X-37. It stands about 6.7 metres tall with a span of about 3.7 metres, roughly one fifth smaller than the X-37. The X-40A never reached orbit. It was carried aloft by a helicopter and released from about 4,600 metres for a series of unpowered glide flights, completing seven approach and landing tests at NASA Dryden in 2000 and 2001. Those flights validated the autonomous flight control system planned for the X-37 and so reduced the technical risk of that programme. Encyclopedia Astronautica files it in the family of spaceplanes and suborbital rocketplanes of the United States.