A memorandum from the ASPO Manager on September 3 summarized the basic and alternate missions for which detailed planning and preparation would be performed. In the basic earth-orbital C prime mission the vehicle configuration would consist of the Saturn V 503 with a payload of 39,780 kilograms (CSM 103 and LTA-B with the service propulsion subsystem fully loaded). Insertion would be into low circular orbit of the earth. The earth-parking-orbit activities would include crew and ground support exercises related to spacecraft system checkout and preparation for translunar injection (TLI; i.e., transfer into a trajectory toward the moon). CSM separation maneuver would occur before TLI.
Alternate earth-orbital missions would include a manned TLI burn to a 6440-km apogee or an SPS burn to achieve a 6,440-km apogee. An alternate lunar orbit mission would include mission planning, crew training, spacecraft hardware, and software to support the mission. In providing support, top priority would be assigned to the lunar orbit mission. The memo indicated that following TLI, simulated transposition and docking maneuvers would be conducted; midcourse corrections and star horizon/ star landmark sightings would be performed during the translunar coast; lunar orbit insertion would be accomplished and a lunar parking orbit established for 20 hours.
On September 13, MSC Director of Flight Operations Christopher C. Kraft affirmed that the impact of supporting the described mission plan had been assessed and no constraints were seen to prevent meeting the launch readiness date. He added that the lunar parking orbit would be established during the course of two elliptic orbits and would be of 16 hours duration, thus giving a total lunar vicinity time of 20 hours.