Since science is not precise they sure did do a hell of a job off of theory and speculation...my point is in a place that is completely a mystery how were they able to estimate everything so correctly without one mistake...keep in mind this is a people who decades later weren’t even able to blast off from earth properly
Breh your “follow up questions” are leading.
I don’t know what you mean by “weren’t able to blast off from earth properly” the Columbia disaster used a completely different space craft, and it exploded because it had been used repeatedly- that was part of its design. Unfortunately the o-rings froze and things went to shyt.
You’re sitting there asking how they knew how they would get off the moon. You’re basically asking how they knew they wouldn’t sink into the moon or some shyt, the answer (which has already been given) is Newtonian gravity. We knew the moon’s mass, we could figure out generally speaking its composition
Have you ever read JFKs speech that was prepared in case Apollo fukked up? There wasn’t any guarantee that they’d all survive.