Mission C DAP initialization procedures

EG/Chief, Guidance & Control DivisionDEC 16 196767-PA-T-120APA/Chief, Apollo Data Priority CoordinationMission C DAP initialization procedures

1. In a memo dated November 28, you recommend that “DAP initialization procedures for Mission G be established where either crew input require- ments are eliminated entirely, or restricted at most to one inertia update following the largest SPS burn.” I am writing you this note to let you know that what has been planned is entirely compatible I think.

2. As of now we do not plan to update the DAP initialization parameters at all during a nominal mission, since we all agree that it is probably unnecessary operationally. There is some concern that doing so, however, would make some of the burns more useful systems tests and we are interested in your Division's (and MIT's) opinion on this. The point is obviously we must establish some ground rules governing conditions under which we would update these parameters, and maybe they should be based on mission objectives rather than operational performance requirements.

3. As you probably know, the RTAFC, our auxiliary computer support facility here in Building 30 which operates during the mission, has programs which will be used to continually maintain a best estimate of all the DAP initialization parameters and the capability exists to load them into the spacecraft computer via the universal uplink. If we do have to update them we will probably load them from the ground, rather than have the crew key them in.