I have been delinquent and I apologize for not sending this note around sooner. About a month ago I learned in a discussion with Joe Loftus that it is his recommendation, apparently based on considerable analysis and review, that the acceptable sun-angle-at-lunar-landing boundaries should be revised. As I understand it, the old sun elevation angle…
Apollo spacecraft computer programs–or, a bucket of worms
Well, I just got back from MIT with my weekly quota of new ulcers, which I thought might interest you. We spent one day discussing the AS-204 situation, another on AS-501 and AS-502, and the third day primarily on crew procedures associated with the LEM lunar rendezvous crew timeline. I will give you my impression…
Reentry guidance is perfect for S/C 101 regardless of L/D
This memorandum is in response to your question regarding the reentry guidance with low L/D. It was erroneously reported to you in the August 3 MPAD Weekly Activity Report that, although the program could be modified easily to handle L/D as low as 0.2, it probably would not be implemented for Spacecraft 101. Actually, some…
Odds and ends about lunar landmark tracking
This memo is just to pass on some numbers which I found interesting when reviewing the lunar landmark orbit determination procedures. It is not intended as an argument “for” or “against” using landmark tracking by the command module for navigation….
Mission H-2 and Subsequent Lunar Orbit Activities
Attached is your copy of the Apollo Mission Techniques Document for the Mission H-2 and Subsequent Lunar Orbit Activities….
Interim progress report – RTCC program development – AS-258(!) Ground Support Simulations Computer [GSSC] programs
I haven’t gone very far into the AS-258(!) GSSC review yet. However, some things are beginning to crystallize. This memo is to list some of the conclusions I have tentatively reached. I would be very much interested in your comments the next time we get together….
Lunar lift off shall be planned at discrete times only.
During our December 21 Ascent Phase Data Priority meeting we concluded that a continuous launch window for lift off from the lunar surface is not a requirement. That is, all mission planning, procedures and program development associated with the nominal lunar landing mission should be based on the assumption that one or more discrete lift…
D Rendezvous Mission Techniques
This memo is to tell you about the results of the November 25 D Rendezvous Mission Techniques meeting. Except for a number of small clean up items, we spent most of our time talking about how to handle slippage of TPI time and incomplete Insertion and Phasing maneuvers. After an exhausting discussion, I think we…
Cis-lunar state vector updating procedure change
A lot of you won’t care – but I want to make sure that those that need to know, do. It deals with state vector updates from the MCC to the CSM during cis-lunar flight on the G mission….
The LM can handle big Descent plane changes but required protection against APS abort fuel depletion
We have recently verified that the LM has a substantial capability to translate out of its initial orbital plane during powered Descent at very little cost. That is, whereas previously a limit of 0.3° had been quoted, it now appears that 1° or more is probably possible without effecting the performance of the guidance equations,…