Neil Townsend (EP2) informed me by phone – and will supply written confirmation – that the minimum duration SPS burn for C’ should be no less than 0.5 seconds. We had been assuming something smaller. According to MPAD (Otis Graf, FM7) this makes the crossover point between use of the RCS versus the SPS engine:…
Year: 1968
Transearth Spacecraft Navigation
During Jim McPherson’s Transearth Spacecraft Navigation Mission Techniques meeting of October 8 and 15, a potpourri of ground rules, working agreements and constraints was established. I may be duplicating other reports with this memo but figure better too many reports than not enough. All of the following apply specifically to the first batch of sextant…
D Rendezvous Open Items, Action Items or whatever you call them
I’ve reviewed my notes of the D Rendezvous meetings over the last couple of months and have found the following open/action items. I guess most, if not all, are being worked on. But time grows short and so I’m sending this list around to make sure of it. If you know of others, please give…
C’ Contingency Procedures – Draft Review
A review of the C’ Contingency Procedures Techniques Document is currently scheduled for October 22, 1968. Topics included are:…
Descent Aborts
We have finally started mission techniques meetings on lunar landing descent aborts. At the risk of losing whatever confidence you might have in my judgment, I would like to describe a technique we are probably going to propose for aborts early in the descent phase. That is, within about 25 seconds of commanding the DPS…
C’ Spacecraft Navigation Mission Techniques
It appears we have completed basic development of C’ Spacecraft Navigation Mission Techniques both for Cis-Lunar and Lunar Orbit. Documentation of these techniques will be distributed in the near future. No further meetings will be called specifically for their subjects. Whatever open items come up will be handled in our weekly C’ Mission Techniques Reviews,…
X-axis or z-axis for LM TPI?
This memo is in response to a question that came up at the October 21 D Rendezvous Mission Techniques meeting. The question was: What is the additional LM RCS propellant cost if we use the z-axis RCS translation rather than the x-axis for TPI? Chuck Pace checked with the MPAD Consumable people who figured the…
Descent Aborts – Part II
This memo is to carry on from that three page snowflake I sent you the other day on the same subject. It turns out we have encountered one of those rare situations when in doing something to fix an undesirable situation we actually improve something else at the same time. Specifically, the rendezvous people want…
CSI and CDH back into the AGS – maybe
Apparently the TRW AGS people have done a good job of putting the new rendezvous radar navigation filter into that dinky computer. In fact, they now estimate a surplus of some 80 words….
Some more C’ Lunar Orbit Mission Techniques
At our October 14 C’ Lunar Orbit Mission Techniques meeting we settled on a few things I would like to tell you about. Along with the TEI block data to be sent up each revolution in lunar orbit, we are also going to update the spacecraft state vector in the CMC every revolution. This will…