A couple of years ago, before any of the lunar flights, GCD started looking into improvements in the LM descent guidance and navigation (G&N) computer programs to compensate for possible problems in rough terrain, landing radar performance, descent targeting by the ground, etc. Actually, they were quite successful; they conceived the socalled delta guidance, prefilter,…
Category: Lunar descent
The LM4 RR/LGC interface may be broken, but that’s okay – sorta
This memo is to document the Data Priority position regarding a recent LM4 systems problem. To wit, it is considered acceptable to proceed with the nominal F mission with a questionable or known interface failure between the rendezvous radar (RR) and the LM spacecraft computer (LGC). It should be emphasized that a properly operating rendezvous…
Proposal to add something nice to the F mission
If it makes sense, I would like to start a campaign to add some actual powered descent into the F mission with an abort about 300 seconds after PDI or whenever it is that the DPS can return the LM to the desired orbit. Could you people please give me a list of the benefits…
LM DPS low level light fixing
I think this will amuse you. It’s something that came up the other day during a Descent Abort Mission Techniques meeting….
No change needed in the landing site determination programs – CMC or RTCC
During a Data Priority meeting a couple of months ago in which we discussed need for lunar landmark tracking, we uncovered what we felt to be a deficiency in the Colossus computer program. It was in the program which is used for determining the location of the landing site. Implicit in the program was the…
G mission lunar descent is uphill – all the way
Just in case you didn’t know, I thought I would send you this note about some nominal G mission landing site characteristics which I thought were kind of interesting. First of all, apparently this landing site (2-P-6) is about 9,000 feet lower than the mean lunar radius. The significance of this, of course, is that…
MIT/MSC review of LUMINARY Descent Programs
On November 2, 1967, a team of Flight Crew, G&C and FCD people met with MIT to discuss the lunar landing descent programs. We have recently been reviewing these programs at MSC and it has become evident that many of the displays and associated computations which we had listed as requirements early in the year…
Some new ideas on how to use the AGS during Descent
This memo is to fill you in on a couple of late crew procedure changes proposed for the G mission regarding AGS operation during descent. The first is a technique to prepare the AGS for immediate ascent which can be used to quickly reinitialize the AGS LM state vector immediately after touchdown if there is…
Descent Monitoring Mission Techniques – a status report
I think we are beginning to see the light at the end of the Descent Monitoring Mission Techniques tunnel. At the April 24 meeting on that subject we thoroughly discussed the integration of the onboard techniques with the activity at the MCC during powered descent and I feel the resultant is as reasonable and complete…
Does the landing radar mess up?
This memorandum is to request that you look further into the business of how the use of landing radar observations in the spacecraft computer during descent influences the onboard determination of the final landing point. Hopefully, the landing point is essentially fixed prior to processing of the landing radar data but that may not be…