Cursory definition of Spacecraft Computer Program capabilities currently planned for AS-503 and AS-504

See listOCT 12 196666-FM1-129FM/Deputy Chief, Mission Planning and Analysis DivisionCursory definition of Spacecraft Computer Program capabilities currently planned for AS-503 and AS-504

One of the possible actions which has been identified to help our space- craft computer program development schedule is to fly the AS-503 mission with the AS-278 programs. I have indicated in previous memoranda that in order to do this we would probably have to add several routines to the AS-278 program to make it applicable for AS-503. However, as we have studied this matter in more detail, we have arrived at a point where only one routine is still considered a candidate — some guidance of the SIVB simulating TLI. This is a command module program. There are no addi- tions contemplated for the LGC. Those interested in exactly what capa- bility would be available are referred to the AS-278 GSOP.

I am sure if we proceed in this way that it will have some impact on establishment of the final mission requirements, and in turn will influence how certain of the spacecraft capabilities for the lunar mission must be tested prior to making the AS-504 flight. I would like to call your attention particularly to the fact that we shall have no navigation (orbit determination) capability other than that associated with rendezvous for the AS-278 and AS-503 missions, nor will we have the ascent or descent guidance equations in the LGC. There has been much discussion on the testing of all of these. Based on recent discussions with ASPO mission planning people, I really don't expect that any mission requirements affected by this decision are of such a mandatory nature that we would be directed to proceed other than I have indicated above. Obviously, if this is incorrect, the sooner we find out about it the better.

Somewhat associated with this, it seems worthwhile to me to provide a list of the additions to the AS-278/503 program which will have to be made for 504. This list, presented below, is MIT's current best estimate and is by no means final, official or definitive, but perhaps it will serve to let you know what the job we have before us is as well as giving you some idea of the capabilities we intend to provide for AS-504.

CMC LGC 1. Return to earth 1. Descent Hohmann Injection guidance 2. LOI guidance 2. Lunar landing guidance 3. Direct intercept targeting 3. Ascent guidance routine 4. Navigation 4. Direct intercept targeting a) SXT star/horizon and star/ routine landmark 5. Orbit integration b) Lunar landmark a) Remove earth orbit 5. Boost monitor b) Add Lunar 6. Orbit integration additions for 6. Lunar rotation a) Trans-lunar operations 7. Lunar landing time prediction b) Lunar operations 8. LGC initialization program 7. Lunar ephemeris program changes 8. Lunar rotation routine 9. Post landing service programs 9. Lunar landing, prediction such as IMU angle storage routine 10. Lunar surface IMU alignment 10. LGC initialization a) Normal 1l. Lunar landmarks (28) b) AOT failure 1l. Launch time determination 12. AGS initialization program changes

Finally, I suppose I ought to add the following remark based strictly on my own intuition — namely, we have almost certainly got a computer storage problem on the AS-504 programs again if all the above items are added to the AS-278 program, particularly with all of the special flexi- bilities and options which will be suggested. Therefore, the face that your favorite processors are listed above does not necessarily mean that we will be able to get them all in.