Project Gemini was the second human spaceflight program of the National Aeronautics and Space Administration. It operated between Projects Mercury and Apollo, with 10 manned flights occurring in 1965 and 1966. Its objective was to develop techniques for advanced space travel, notably those necessary for Project Apollo, whose objective was to land humans on the Moon. Gemini missions included the first American extravehicular activity, and new orbital maneuvers including rendezvous and docking.