This US postal cover is commemorating the landing the NASA Space Shuttle STS-1 mission in 1981.  The cover was postmarked on April 14, 1981 at Edwards AFB California, and has cachet noting the event.  It was postmarked by former NASA Astronauts George Nelson and Mike Mullane, both who were STS-1 landing astronaut support members.  The item is in great condition.

STS-1 was the first orbital spaceflight of NASA's Space Shuttle Program. The first orbiter, Columbia, launched on April 12, 1981, and returned on April 14, 1981, 54.5 hours later, having orbited the Earth 37 times. Columbia carried a crew of two—commander John W. Young and pilot Robert L. Crippen.