[dgfl]

Yes, this is a fair point. I agree that orbital mechanics is trivially easy compared to everything else. The chances of a math mistake in particular are null, these trajectories have all been calculated years in advance.

[WalterBright]

The lumpiness of the moon's gravity is not well mapped out.

[accrual]

It is now better mapped after the GRAIL mission: https://en.wikipedia.org/wiki/Gravity_Recovery_and_Interior_...