Boeing X-20 Dyna-Soar Space Plane (1957-1963)

The Boeing X-20 Dyna-Soar ("Dynamic Soarer") was a United States Air Force (USAF) program to develop a spaceplane that could be used for a variety of military missions, including aerial reconnaissance, bombing, space rescue, satellite maintenance, and as a space interceptor to sabotage enemy satellites.

By the end of 1962, Dyna-Soar had been designated X-20, the booster (to be used in the Dyna Soar I drop-tests) successfully fired, and the USAF had held an unveiling ceremony for the X-20 in Las Vegas.

The program ran from October 24, 1957, to December 10, 1963, cost US$660 million ($6.31 billion in current dollars), and was cancelled just after spacecraft construction had begun.