/sci/ - Science & Math

A comparison of the major flight events of the Apollo program's missions.

Motivation: The Apollo program's missions followed a rigid schedule and flight profile, which was used repeatedly. At the same time, each mission was unique: major equipment was absent from earlier flights, an emergency was managed successfully on Apollo 13, and other equipment and problems altered the timing of phases on the six "profile" missions which accomplished lunar landings. In short: the timing of the missions' phases were alternately comparable, and unique, so that it is feasible to compare them in a data set.

Methodology and Scope: Rounding to the nearest second, each mission's major mechanical events (stagings, separations, dockings, landing gear extension) are rounded to the nearest second, using AFJ, ALSJ and flight transcripts as sources. The GET timecodes are then converted into second timecodes, or seconds elapsed from range zero. The mechanical events are then used as endpoints for intervals of time during a mission when the launch vehicle, or spacecraft, are in particular configurations. Summing a column's results gives the total seconds from range zero to splashdown-on J-missions, this was about one million seconds. Seconds are chosen because they make it straightforward for a reader to inspect a fairly small table of natural numbers, (as opposed to hour-minute-second timecodes) and quickly pick out extrema.

Results: a numerical table of data show at a glance the commonalities and differences among the missions. The launch phase, in grey, proceeded with very little variation, and therefore extrema are not considered here. Following S-II separation, the missions' commonalities and unique characters become clear, in terms of duration of flight phases. Selected examples include Mike Collins' record re-acquisition of the LM/S-IVB stack on Apollo 11, and the long period of joint CSM/LM flight on Apollo 16 due to an alignment issue.