Gemini 9B was a crewed spaceflight mission conducted by NASA in June 1966. It was part of the Gemini program, which aimed to develop space travel techniques for future missions, including Apollo. The mission's primary objectives included testing spacecraft systems and conducting a spacewalk. Astronauts Eugene Cernan and Thomas Stafford flew aboard the Gemini 9A spacecraft. During the mission, Cernan performed a spacewalk, becoming the second American to do so. The mission faced challenges, including difficulties with the spacewalk and a malfunctioning spacecraft, but it successfully completed its objectives and contributed valuable data for future missions.