NASA’s Project Gemini was designed to test technologies and techniques for the Apollo Program. The two-man Gemini spacecraft was larger and more sophisticated than its Mercury predecessor.

The spacecraft was designed by a team of NASA engineers led by Jim Chamberlin, and built by McDonnell Aircraft, in St Louis. There were two uncrewed test flights (1964, 1965) and 10 crewed (March 23, 1965 until November 11–15, 1966) all launched on a Titan II missile. The Gemini flights helped NASA learn to work and live in space, paving the way for the successful Apollo human landings on the Moon.