We left off last week after Buzz Aldrin’s third and final EVA. The hard work for the Gemini 12 mission was now complete. Even with the problems with the radar, the Agena main engines, and the fuel cells, Gemini XII as a whole had gone very well…
The Gemini Program was conceived after it became evident to NASA officials that an intermediate step was required between Project Mercury and the Apollo Program. The major objectives assigned to Gemini were:
1-To subject two men and supporting equipment to long duration flights — a requirement for projected later trips to the moon or deeper space.
2-To effect rendezvous and docking with other orbiting vehicles, and to maneuver the docked vehicles in space, using the propulsion system of the target vehicle for such maneuvers.
3-To perfect methods of reentry and landing the spacecraft at a pre-selected land-landing point.
4-To gain additional information concerning the effects of weightlessness on crew members and to record the physiological reactions of crew members during long duration flights.
On orbit 48, after 75 hours of flight a problem arose. During a pass over the continental US the flight computer was updated. McDivitt was told to switch off the computer. He flipped the switch but the computer did not turn off. On the ground at mission control, efforts to solve the problem began immediately. For the next few orbits, the crew received instructions for trying different switch positions, after all the switching the computer finally failed entirely and could not be turned back on. Now the astronauts would have to resort to a rolling Mercury-type reentry, rather than the lifting bank angle the computer was supposed to help them achieve…