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I'm reconstructing the entire apollo 11 mission trajectory.

I'm now at the moon landing. Does someone know specific documents specifying longitudes and latitude at the different interfaces starting from the Power Descent Initiation to the Touchdown. I don't need the entire lon / lat history, just the values at the interface points (e.g., at PDI, end of braking phase, end of approach, etc.)

I found the NASA TN D-6846 (Apollo Experience report - Mission Planning for Lunar Module Descent and Ascent), but specific numbers are not given.

"Apollo by the numbers" does not have that either.

Any extra reference you might know?

Thanks!

Edit: although the question here seems similar, the replies and the references given to that question are not specific enough (e.g., lon / lat at the end of breaking and approach phase are not really specified) or not relevant (apollo 8 that is mentioned there did not have any lunar landing phase), therefore I'd like to keep this one open in case someone has more specific details not found over there.

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    $\begingroup$ this is interesting, but wouldn't you also need altitude? $\endgroup$
    – Topcode
    Commented Apr 2, 2020 at 3:33
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    $\begingroup$ Does this answer your question? If I wanted to reconstruct an entire Apollo mission's crewed spacecraft trajectories, what are the key sources of historical data I'd look for? $\endgroup$
    – Organic Marble
    Commented Apr 2, 2020 at 3:54
  • $\begingroup$ @Topcode the altitude is in there. But longitude and latitude are only roughly shown. $\endgroup$
    – venom
    Commented Apr 2, 2020 at 3:55
  • $\begingroup$ Hi @OrganicMarble Brauenig covered mostly the ascent part. The mission report with the table is useful, thanks, (I already had a look at it) but there is only PDI lon / lat, not the intermediate points until the landing. And I'm not completely sure it is 100% accurate (for example at the PDI it gives a positive fpa of 0.03°, while it should be negative instead) $\endgroup$
    – venom
    Commented Apr 2, 2020 at 3:59
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    $\begingroup$ @uhoh thanks, I just did what you suggested! $\endgroup$
    – venom
    Commented Apr 2, 2020 at 5:49

2 Answers 2

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The parameters for the Apollo lunar descents are too complicated to explain here. However, the entire May-June 1972 issue of the Bell System Technical Journal volume 51 number 5 (30 Mb pdf, 176 pages) was devoted to documenting the planning of the Apollo program.

Pages 1046 to 1048 describe the descent trajectory. It includes these pictures: LM descent trajectory visibility and landing phases

Appendix B has the descent trajectory details, the guidance equations, and graphs of thrust and pitch as a function of time.

Enjoy!

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  • $\begingroup$ Hi @DrSheldon, thanks! I already knew the figures above, but not the report you mentioned. I'll check it out! $\endgroup$
    – venom
    Commented Apr 2, 2020 at 7:13
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The Apollo 11 Mission Report (MSC-00171 of 11/1969) claims for PDI:

1.037º latitude, 39.371º longitude @ 49,376 feet (best estimate; primary guidance computer had slightly different values)

(Table 5-III, p 5-14).

The document also gives no less than 8 different sets of landing coordinates from different sources (table 5-IV, 5-15).

There's a lat/long/altitude chart for the lunar ascent phase on p 5-37, but I don't see one for descent.

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