12. Gemini VI was launched after Gemini VII as Gemini VI A
Gemini VI was originally supposed to be launched on October 25, 1965, following the launch of an Agena Target Vehicle which it was scheduled to rendezvous with during its flight. The Agena launched but exploded in flight causing the mission to be canceled. In December, Gemini VI was scheduled to rendezvous with the already orbiting Gemini VII, which was on a fourteen-day endurance flight in a stable orbit. The first attempt to launch Gemini VI A failed on December 12, when the booster ignited and then shut down. Procedure required astronaut Wally Schirra to activate the ejection seats, but he elected not to since he had not felt the booster move. Ejection would have likely been fatal and would have at least destroyed the spacecraft even if the astronauts had survived.
Gemini VI A was finally launched on December 15, and on its fourth orbit, it achieved rendezvous with Gemini VII. Schirra was able to perform a fly-around inspection of his fellow spacecraft, and the two capsules flew side by side, keeping the station on each other and communicating over the radio. At one point the spacecraft were as close as one foot to each other. The rendezvous and the ability to fly together were techniques necessary for a trip to the moon, and the two American capsules performing the maneuvers exhibited clear evidence that the Americans were now ahead of the Soviets in the Space Race of the 1960s. Gemini VI withdrew to a safe distance during the sleep period following the rendezvous, which lasted four and one-half hours. It returned to earth the following day.