In this comment I just wrote:
"...but at all other times it is just doing math to calculate its trajectory." The math needed a stable clock Timing accuracy of the Apollo Guidance Computer? (also 2, 3) and an ephemeris to look up the positions of the Earth and Moon as a function of time to calculate which way their gravitational accelerations are pointing.
But now I wonder how the Apollo guidance computer software accounted for the motion of the Earth-Moon system's orbit around the Sun during the few days the astronauts spent traveling between the two.
- Did the software have a look-up table for the position of the Earth-Moon barycenter relative to the Sun?
- Or was there just a centrifugal pseudo-force term based on an average distance to the Sun?
- Or something else?
- Or nothing at all?