Gemini 9A ( officially Gemini IX-A ) was a 1966 crewed spaceflight in NASA 's Gemini program . It was the seventh crewed Gemini flight , the 13th crewed American flight and the 23rd spaceflight of all time ( includes X-15 flights over ) . The original crew for Gemini 9 , command pilot Elliot See and pilot Charles Bassett , were killed in a crash on February 28 , 1966 while flying a T-38 jet trainer to the McDonnell Aircraft plant in St. Louis , Missouri to inspect their spacecraft . Their deaths promoted the backup crew , Thomas P. Stafford and Eugene Cernan , to the prime crew . The mission was renamed Gemini 9A after the original May 17 launch was scrubbed when the mission 's Agena Target Vehicle was destroyed after a launch failure . The mission was flown June 3 – 6 , 1966 , after launch of the backup Augmented Target Docking Adaptor ( ATDA ) . Stafford and Cernan rendezvoused with the ATDA , but were unable to dock with it because the nose fairing failed to eject from the docking target due to a launch preparation error . Cernan performed a two-hour extravehicular activity , during which it was planned for him to demonstrate free flight in a self-contained rocket pack , the USAF Astronaut Maneuvering Unit . He was unable to accomplish this due to stress , fatigue , and overheating
crash
1966 NASA T-38 crash
Gemini 9A