On September 12 we had a spacecraft computer program requirements meeting for Apollo 13. We called it because there were a lot of proposals floating around which had been advertised as “needed for point landing.” On the other hand, these programs must be released for rope manufacture on about November 15 and so there obviously…
Category: Lunar descent
Important LM computer program change for Apollo 13 descent
There were some things about the terminal descent on the last mission that kind of spooked a lot of people. One of the things suggested as a result of this was to add a capability to the LM guidance and control system which would assist the crew during the last 100 feet or so of…
Current status on the LM DPS engine gimbal caution light problem
This memorandum is to report the results of a very brief investigation into the adequacy of the LM Descent Propulsion System (DPS) engine gimbal caution light. Briefly, this light comes on if a difference between the gimbal drive signal and the gimbal response signal from the Y or Z axis trim malfunction logic is sensed….
Results of September 17 Apollo Spacecraft Software Configuration Control Board (ASSCCB) meeting
The first three hours of this marathon meeting were devoted to implementation of the descent program in LUMINARY. The currently approved plan is to implement the one-phase descent scheme proposed by Floyd Bennett and his merry crew. However, MIT has been directed to implement it in such a way that it would be possible to…
When is the rendezvous radar designate routine (R29) needed?
George Cherry (MIT) asked if it is possible to drop the rendezvous radar designate routine (R29) out of the descent abort programs (P70 and P71). He gave me the impression that to do so now would significantly reduce their work and permit concentration in testing in more profitable areas. I don’t know when the next…
F and G Lunar Orbital operations – mostly pre-DOI LM activation stuff
On January 10 we had an F and G Mission Techniques meeting dealing mostly with Lunar Orbital operations, which I would like to record with this thing….
Descent Aborts and subsequent Rendezvous Mission Techniques
On April 28, 1969 we reviewed the Descent Aborts and subsequent Rendezvous Mission Techniques with the crew and the rest of the world. I think most of this is quite complete and agreeable to everyone concerned, with one major exception. I was shocked and ashamed to find that I had badly misunderstood the situation regarding…
Apollo Mission Techniques Documentation Schedule
Here is another Mission Techniques Documentation Schedule, since the last one is three months old and barely reflects real life any more. The Lunar Orbit Activities Document will almost certainly have to be updated to reflect whatever we learn on the F mission. A June 30 release date for that update will be kinda late,…
No need to perform lunar landmark orbit determination
A number of Trajectory Control Data Priority meetings have been held on the Descent phase of the lunar landing mission. A basic question arose early in these meetings regarding lunar orbit landmark tracking with the command module sextant and/or telescope. It was necessary to decide whether or not such observations are required for use in…
Tweak burns
If you can stand it I would like for you to hear the latest on tweak burns – the trim maneuvers made after LM insertion from a descent abort. I thought we had this settled and on ice a couple of months ago but some things have happened which probably make it logical to revise…