There are two memorandums with the serial 68-PA-T-71A
Upthread: First “E” Mission Rendezvous Mission Techniques meeting – March 4 (Mar 07, 1968)
Downthread: List of “D/E” Rendezvous open items (Apr 16, 1968)
See list belowAPR 5 196868-PA-T-71APA/Chief, Apollo Data Priority CoordinationMission “E” Rendezvous Data Priority meetings
1. This memorandum is to report the meager accomplishments of the Second and Third “E” Rendezvous Mission Techniques meetings of March 18 and April 1, 1968.
2. Much of the first meeting was devoted to trying to understand what the people responsible for AGS system testing were trying to accomplish in the mission, in order that the techniques developed would be compatible. Essentially, what came out of this lengthy quiz session is that they do not want the AGS reinitialized from the PGNCS, they want radar data input between the CSI and pseudo-TPI maneuver during the first half of the rendezvous exercise, and they want to execute the maneuvers as determined by the AGS provided they fall within acceptable bounds. There was a hopefully erroneous impression that a well thought-out systems test including post-flight analysis procedures does not exist which would be ludicrous to discover after the mission.
3. A substantial part of the latter meeting was devoted to the possibility that LM RCS propellent will not be adequate to support the currently planned rendezvous exercise. The mission plan is not our responsibility, of course, but significant changes to it could impact our works severely. it is anti- cipated that the FOD and ASPO mission design engineers will get this all straightened out soon. My impression was that if the LM can not fly the “D” rendezvous, it can not fly any rendezvous. In any case, at this meet- ing, we proceeded on the assumption that the trajectory, as it is currently planned for the “D” rendezvous, will be used for the “E” rendezvous as well. We spent some time bringing those people not familiar with “D” up to date. This included a description of the mirror image concept for targeting the command module to back up LM maneuver and the procedures which are beginning to take shape for aborts from the football trajectory in the beginning of the exercise and the pseudo-TPI half way through it. A lengthy inconclusive discussion on how to compare and use the various systems for the TPI maneuver ended the meeting.
4. A few things that have been definitely established are as follows:
a. It was stated that we want to make a PGNCS platform drift test before we embark on the rendezvous exercise. This means making two fine alignments spaced in time sufficiently to observe excessive drift. This is almost impossible to accomplish unless we make a fine alignment in the docked configuration. Therefore, that activity is being included in the operation.
b. We reviewed a previous decision and decided to always update targeting for the insertion maneuver. This maneuver, you recall, is the one that takes the LM out of the football trajectory. The primary reason for always updating is to eliminate need for developing the logic and criteria to make a real time decision of whether or not to update. The point is this exercise is busy enough already without adding an extra task and it would have to be included in the timeline anyway.
c. With regard to the mirror image CSM targeting, there seemed to be two alternatives which must be taken into account, some sort of system failure recognized well in advance of the maneuver and some sort of pro- pulsion failure after ullage but before main engine ignition. Accordingly, this must be taking this into account in targeting the command module. Ed Lineberry was given the action item of establishing this technique to be incorporated in with maneuver biasing already being provided to compen- sate for the one minute delay in CSM ignition time.