C’ Contingency Review

See list attachedOctober 25, 196868-PA-T-234APA/Chief, Apollo Data Priority CoordinationC’ Contingency Review

We went through the draft of the C' Contingency Mission Techniques document on October 22, and I must say I was impressed with its quality. It seemed to me the Flight Analysis Branch, the Apollo Abort Working Group, and TRW had done a good job of putting this together. The final version will be distributed within the next week or so.

One item that came up needed resolution deals with the block data maneuvers – that is, those abort maneuvers which the MCC-H periodically sends to the spacecraft to be used in the event of a subsequent complete communication failure. It is necessary to agree on the targeting objectives of these maneuvers. First of all, let me emphasize that the free return trajectory that we adhere to on the way to the moon does not necessarily provide a water landing and almost assuredly does not provide a landing near the primary recovery forces. All it does it to make sure that the spacecraft can get back to earth with minimum ΔV in the event of an SPS failure. The question to be answered is: Should the block data maneuvers merely be designed to provide a water landing or should they also meet the additional constraint of landing in the planned recovery area – that is, targeted to the CLA? We had been assuming that they would aim for the CLA, although, this may require maneuvers of as much as 1200 fps. Some people were ques- tioning whether it would be better to avoid making a maneuver any larger than is necessary to insure a water landing regardless of where it might occur. Basically, it is a tradeoff between a maneuver (of up to 1200 fps) to get where we really want to go versus a smaller maneuver (up to 250 fps) to provide a safe landing somewhere. Of course, there is also the question during the translunar coast of when to target the maneuver for a direct return which costs a lot of ΔV (up to 7,000 fps) as opposed to going around the moon, which is much cheaper. These things are really mission rules which must be established before the flight. They apparently aren't agreed to yet. At least I don't know the rule.