Falcon 9 first successfully landed its first stage after an orbital launch during SpaceX’s Falcon 9 flight 20 on December 21, 2015.
The mission launched eleven Orbcomm communications satellites from Cape Canaveral in Florida. After separating from the upper stage, the first stage performed engine burns and guided itself to Landing Zone 1 near the launch site.
This was the first successful landing of an orbital-class rocket’s first stage. Earlier attempts had demonstrated controlled descent or ended in crashes, and several later missions initially targeted drone ships at sea.
The achievement made routine reuse of large rocket stages more practical. Falcon 9’s upper stage was not recovered on this mission, so the milestone concerns the first stage rather than the complete rocket.