Terminal phase transfer angle may be changed to 130°

See list belowFEB 7 196868-FM-T-23FM/Deputy ChiefTerminal phase transfer angle may be changed to 130°

1. Extensive analyses were carried out in preparation for Gemini rendezvous which led to our selection of a 130° terminal phase transfer angle. Entirely independent analyses on Apollo apparently have led to selection of 140° for the rendezvous transfer angle. More recently, however, people in the Flight Crew Operations Directorate have been re-examining this and, according to Buzz Aldrin, may soon come to the conclusion that there is sufficient advantage to change to 130°. The primary reason is to minimize the line of sight rates during the terminal braking in an effort to reduce fuel used unnecessarily to eliminate perfectly nominal trajectory characteristics inherent in the present 140° transfer.

2. Since this proposal will influence the development flights as well as the lunar, it would be well to get it resolved ASAP. Accordingly, it will be discussed next Monday, February 12, at the “D” Mission Rendezvous Mission Techniques meeting to at least air the “pros” and “cons” and to see who is for and who is agin.