As you probably recall, we have had an exchange of views and memoranda regarding the usefulness of the Apollo computer program known as self-check. This exchange was started by our attempt to cut the spacecraft computer program down to an acceptable size for the lunar mission. Current status is that the self-check programs are still in; however, I intuitively feel the 504 programs have probably again grown to a point that we have again overflowed storage and will eventually have to have another paring down session. I would like to request that your people who expressed an interest in preserving self-check assume the task of formulating applicable mission rules which could be used on the lunar mission in conjunction with the self-check programs. These mission rules would specify exactly what action is to be taken during the 504 mission, probably as a function of mission phase and type of computer failure detected by self-check.

The point is, I would like to make sure that this program really serves a useful operational function as opposed to a pre-flight function before we decide to carry it to the moon at the exclusion of some other program someone wants. And, of course, if we do retain it in the system, these recommended mission rules should be very useful to the Flight Control Division and to the flight crew in establishing the operational procedures.

Terms & Abbreviations


see AS-504


Before the Apollo 1 fire, the mission referred to as AS-504 was originally scheduled for December 1967. AS-504 eventually launched as Apollo 9, March 3 1969.