Gemini mission. View from a Gemini manned spacecraft during rendezvous with an Agena Target Vehicle (cylindrical structure). An astronaut is then shown performing a spacewalk, and a view of the Earth ends the clip. Gemini was an American human spaceflight programme which ran from 1961 to 1966. The Gemini spacecraft carried a two-astronaut crew, and ten crews flew low Earth orbit missions between 1965 and 1966. The Agena Target Vehicle (ATV) was an unmanned NASA spacecraft used to develop and practise orbital space rendezvous, docking techniques, and large orbital changes. These projects were designed to develop techniques to support the Apollo lunar missions.