Found this particular comment to be interesting regarding the Apollo 10 mission, which I had never heard before:
"Apollo 10 would get within nine miles of the lunar surface — so close that NASA intentionally under-fueled the Lunar Module so the two occupants, Stafford and Cernan, wouldn’t be able to get home if they were tempted into landing."
Imagine if, while Stafford and Cernan were flying the L.E.M above the moon's surface on it's excursion test-flight, something had gone wrong and it turned out that they needed that extra fuel that NASA intentionally shorted them, in order to get back safely to dock again with the Command Module, and they ended up running out of fuel and crashing down on the moon's surface, forever to remain as a HIDEOUS "monument" to man's mistakes on the surface of the moon for ALL to see!! I know, I know......not a very likely scenario......then again, the history of the Mercury, Gemini, Apollo and Shuttle programs ended up exposing some VERY disastrous scenarios that NASA never saw coming, some of which were (barely) surmounted, and some which, sadly, weren't (i.e., Gemini 8, Apollo 1, Apollo 13, Challenger Shuttle, Columbia Shuttle, etc.) ....
Apollo 10 May, 1969 - The 'Dress Rehearsal' for Apollo 11’s Triumphant Landing That Would Come Just A Few Months Later: