The crew assignments for Gemini 8 were announced on September 20, 1965, with Armstrong as Command Pilot and David Scott as Pilot. Scott was the first member of the third group of astronauts to receive a prime crew assignment. The mission launched on March 16, 1966; it was to be the most complex yet, with a rendezvous and docking with the unmanned Agena target vehicle, the second American extra-vehicular activity (EVA) by Scott. In total, the mission was planned to last 75 hours and 55 orbits. After the Agena lifted off at 10 a.m. EST, the Titan II carrying Armstrong and Scott ignited at 11:41:02 am EST, putting them into an orbit from where they would chase the Agena.[49]
The rendezvous and first-ever docking between two spacecraft was successfully completed after 6.5 hours in orbit.[1] Contact with the crew was intermittent due to the lack of tracking stations covering their entire orbits. Out of contact with the ground, the docked spacecraft began to roll, and Armstrong attempted to correct this with the Orbital Attitude and Maneuvering System (OAMS) of the Gemini spacecraft. Following the earlier advice of Mission Control, they undocked, but found that the roll increased dramatically to the point where they were turning about once per second, which meant the problem was in their Gemini's attitude control. Armstrong decided the only course of action was to engage the Reentry Control System (RCS) and turn off the OAMS. Mission rules dictated that once this system was turned on, the spacecraft would have to reenter at the next possible opportunity. It was later thought that damaged wiring made one of the thrusters become stuck in the on position.[50]
Throughout the astronaut office there were a few people, most notably Walter Cunningham, who publicly stated that Armstrong and Scott had ignored the malfunction procedures for such an incident, and that Armstrong could have salvaged the mission if he had turned on only one of the two RCS rings, saving the other for mission objectives. These criticisms were unfounded; no malfunction procedures were written and it was possible to turn on only both RCS rings, not just one or the other. Gene Kranz wrote, "the crew reacted as they were trained, and they reacted wrong because we trained them wrong." The mission planners and controllers had failed to realize that when two spacecraft are docked together, they must be considered to be one spacecraft.[51]
Armstrong himself was depressed[52] that the mission had been cut short, canceling most mission objectives and robbing Scott of his EVA.