STS-36 was a NASA Space Shuttle mission, during which Space Shuttle Atlantis carried a classified payload for the U.S. Department of Defense (believed to have been a Misty reconnaissance satellite) into orbit. STS-36 was the 34th shuttle mission overall, the sixth flight for Atlantis, and the fourth night launch of the shuttle program. It launched from Kennedy Space Center, Florida, on 28 February 1990, and landed on 4 March.