FM/Technical AssistantJUL 27 196767-FM-T-46FM/Deputy ChiefLanding point dispersions given communication loss in lunar orbit
1. During Chris Kraft's staff meeting of July 17 there was a long discussion regarding the necessity of a beacon to help the recovery people find the spacecraft. It was pretty well concluded that it was not needed as long as we knew where the spacecraft landed to within several hundred miles. Of course, if the various guidance and tracking systems are in operation we should certainly know the landing point much better than that and so the beacon is coming off.
2. The reason I am writing this note to you is that it occurred to me that if we were to lose communication with the command module while in lunar orbit subsequent to separating from the LM, maneuvers would have to be computed and executed based on onboard information. (Of course, the TEI maneuver would be carried out using the clack data transmitted prior to communication loss.) It is probable that the mid-course navigation would have to utilize star-horizon observations to obtain the state vector which would be used for mid-course correction maneuvers and for initializing the reentry guidance systems. I'll bet the landing dispersion under these conditions could be very large, although Pete Frank, who was sitting next to me, felt it would still be within several hundred miles. In any case, I asked him to look into this situation to make sure we have not overlooked something that might bear on the beacon decision. It is to be noted that this contingency situation is of a high enough possibility that we are providing several large computer programs onboard the spacecraft to handle it. Would you see that all the necessary task assignments, etc., are taken care of if you agree this job should be done.
1967_tindallgrams.pdf
