Spacecraft computer program status for AS-501

See listSEP 20 196666-FM1-108FM/Deputy Chief, Mission Planning and Analysis DivisionSpacecraft computer program status for AS-501

This memorandum is to give my impression of what went on during the meeting MIT on September 12, 1966, regarding the AS-501/502 space- craft guidance computer program. Primarily I would like to describe the status of this program as we see it now.

We had previously been aiming for a release of the flight program for rope manufacture on October 10. However, Dan Likely (MIT), who has recently taken over management of this program, informed us that the recent intense activity on the AS-204 program had completely saturated the 1800 computers they all use for program development. As a result, they had not been able to make a single computer run on the AS-501 program for a period of about two weeks. This has seriously disrupted their planned program development and it was Dan's recommendation that we delay release of this program until October 24, if at all possible. Assuming adequate availability of the computers, Dan expects to finish verification runs by October 10 and wishes to utilize the extra two weeks for evaluation these tests to assure himself of flight readiness prior to its release. Aaron Cohen checked with his associates who are affected by this schedule and was able to negotiate this delay, which we all felt to be highly desirable in order to avoid a repetition of the AS-204 situation. In that case, you recall, we were forced to release the program before some of the verification tests had even been run and before the test results had been examined. It is probably worth noting that Dan Likely appears to be taking over quickly and doing a very good job. At least I certainly feel a great deal of confidence in his ability to do this job right and on schedule. We intend to schedule a Software Panel final status review on October 18, to be followed by a presentation to all interested MSC personnel a week or so later.

AC Electronics was represented at this meeting and reported that nine of their people are now temporary residents at MIT, working exclusively on the AS-501/502 AGC mission programming effort. It fact, they constitute almost the entire work force at Likely's disposal. It is my impression that they have come onboard and have become effective very quickly. Part of their effort involves development of a simulation of the Saturn V, which is required for program checkout. (Likely identified this as one of the major remaining problem areas.)

AC also has a 21-man effort operation in Milwaukee. These people are developing an independent verification facility for Block I programs which they hope to have operational about September 19. This includes an “automatic checkout system” capability which among other things is supposed to reconstruct the actual program symbolically, this allowing rapid and easy examination of the equations which have actually been programmed into the system. Considering all of the programming effort, both coding and verification, ahead of us at MIT over the next several months, it seems essential to me that we make maximum use of this AC facility. I mean we must not use it in parallel with MIT's, but instead of MIT's, wherever possible. MIT has been directed to provide detailed test plans showing how these facilities will be used.

Most of the meeting was devoted to discussion of changes to the AS-202 program for AS-501 and selection of values for some of the flight para- meters. With a few minor exceptions, this all seems to be progressing very nicely.

We finally verified, to the limit of our ability, that the AS-501 pro- gram may be used without change for AS-502. MIT was requested to list possible problem areas, if any were recognized, particularly associated with fixed memory constants. Carl Huss was to call an MSC meeting to re-examine this subject from a trajectory standpoint on September 15. (This has been done and as of today, we know of no reason these programs cannot be identical.)

That's about it for the AS-501 meeting. On Tuesday we discussed the Program Development Plans for AS-503 and AS-504 which I will report in another memorandum — if I have the nerve.