See list belowJAn 11 196868-FM-T-3FM/Deputy ChiefOdds and ends about lunar landmark tracking
1. 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 track- ing by the command module for navigation.
2. It is John Dorenbach's opinion that in order for a landmark to be visible by earthshine it must be in the order of 3,000 to 4,000 feet in diameter. It is his estimate that landmarks located by Lunar Orbiter photographs could be pinned down to within about 4 to 6 kilometers.
3. I would conclude from this that landmarks in earthshine and landmarks located by the Lunar Orbiter could be used for onboard orbit determination, but that the resulting ephemeris would be significantly more in error than published estimates of landmark tracking navigation accuracy using properly illuminated and located job-ee-dos, as Pete Conrad would say.
- Dec 15, 1967 – Some lunar landmark tracking questions (7.6σ)
- Feb 05, 1968 – Landmarks must be referenced to Irene’s earth. (6.0σ)
- Feb 21, 1968 – Landmarks for lunar tracking (3.1σ)
1968_tindallgrams.pdf
