Apollo Saturn 201 employed the Saturn IB launch vehicle, which was the up-rated version of the Saturn I rocket flown in ten earlier Saturn-Apollo missions. It featured an upgrade of the first stage engines to increase thrust from 1,500,000 lb-ft of thrust to 1,600,000 lb-ft. The second stage was the S-IVB. This stage used a new liquid hydrogen-burning J-2 engine which would also be used on the S-II second stage of the Saturn V lunar launch vehicle…
The Apollo contract specified a shirt-sleeve environment. For this reason, North American was told not to include in its design a hatch that opened by explosives, like Mercury’s. An accidentally blown hatch in space would cause an instant vacuum and certain death for an astronaunt not wearing his pressure suit.
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.
From the previous episode, we have Gemini VII waiting in orbit for Gemini VI-A to launch and rendezvous. Remember, Gemini VII could only remain in orbit for 14 days, the maximum duration of its flight. The goal was to launch Gemini VI-A on or before day 9 of Gemini VII’s mission.