Roughly 288 hours after Lunar midnight a small gold and silver craft descended from orbit and touched down on the surface of the Moon. The date was
July 20, 1969 at 2017Z. Within hours the history books on Earth would change forever.
Here's a little 'factoid' I found interesting. The timing of the Moon landing was very intentional (as one might expect, but maybe not for the
reasons you thought). The timing was planned to coincide with Lunar 'morning' on the Moon. Everything had been planned out, but no one had ever
actually set foot on the Moon before that day, and no one was 100% certain how all the theories would work. They were pretty confident all the
equipment would survive (provided they didn't crash), but the human element still had a degree of uncertainty. How would mankind survive the dramatic
temperature swings of the Moon?
Well, for one thing, the astronauts would never experience the full temperature swings on the Moon, they wouldn't be there long enough. A Lunar day
is (27) Earth days long. In this time the temperature at the Moon's surface swings from -280F to +260F. Some quick math will tell you this means the
temperatures increase from their lowest to their highest at a rate of roughly 40F degrees per Earth day, and that the surface temps would be at about
0F degrees roughly 288 hours after Lunar midnight. This would allow a margin of 3 days (in the event of a problem) before temps reached 120F.
Now, temps don't work the same way on the Moon as they do on Earth because there's no atmosphere to heat up, so the only two ways things get hot is
through radiant heat and conductive heat. The space suits were designed to reflect 90% of the radiant heat, and their boots were insulated to isolate
conductive heat as much as possible (hence the thick soles on the actual Moon overshoes and the old Moon Boots of the 70's). In any case though, heat
was still a concern, especially extreme high temperatures.
Of all the Moon missions, Apollo 17 spent the longest time on the surface of the Moon (3 days). But even Apollo 17 considered heat, so it started
earlier (colder) in the Lunar day.
And one other little interesting factoid, Buzz Aldrin reported noticing how his helmet got hotter in the sun than in the shade of the Moon, but
noticed no temperature changes in his suit going from sun to shadow. So maybe at the end of the day, the helmet would have been the weak link in Moon
EVA's. In any case, the engineers probably planned it just right.
Probably useless trivia, I know, but I thought some might be interested.
edit on 1/15/2019 by Flyingclaydisk because: (no reason