See list attachedJanuary 14, 196969-PA-T-4APA/Chief, Apollo Data Priority CoordinationF and G cis-lunar midcourse correction scheduling
This memo is to make sure everyone is aware that we are scheduling the final midcourse corrections before LOS and Entry differently than on C'.
The final translunar midcourse correction shall be scheduled at LOI – 5 hours since that provides optimum midcourse correction effective- ness and confidence in subsequent MSFN tracking for LOI targeting. You recall on C' this maneuver was at LOI – 8 in order to provide a short crew rest period after that. This is not required on the F and G missions at this time.
The basic criteria for selecting EI – 2 hours as a last transearth midcourse correction was to make it as late as possible while still providing adequate MSFN tracking for entry initialization. On the C' mission it was found that although two hours is adequate, an addi- tional hour would be advantageous. Since there appears to be no dis- advantage to moving this maneuver one hour earlier to EI – 3 hours we propose to do so. One associated item North American is going to check out is with regard to the effect of this on the RCS quads. There is a slim possibility that this schedule may present a thermal problem.
I would like to emphasize that the intermediate cis-lunar midcourse correction schedule is not based on trajectory consideration but rather will be selected to fit most conveniently in the crew work/rest cycle just as it was done on C'. Accordingly, the scheduling of these maneu- vers must await development of the flight plan after which they will be shuffled in at the most convenient times.