|Gemini 9 was launched on June 3, 1966, with Thomas Staford and Eugune Cernan aboard. The two astronauts originally scheduled for the mission, Elliot M. See and Charles Basset, had died in a plane crash. The three-day mission was plagued by a number of difficulties. The planned docking was called off due to a protective cover on the Agena target vessel that remained attached. Cernan's planned space walk was also called off because the astronaut's heavy breathing caused his face plate to become fogged beyond the air conditioning unit's ability to handle it.