It's a brilliant surface in that sunlight. - Neil Armstrong

It is true that we were cautious in our planning. There were many uncertainties about how well our Lunar module systems and our Pressure suit and backpack would match the engineering predictions in the hostile lunar environment. We were operating in a near perfect vacuum with the temperature well above 200 degrees Fahrenheit with the local gravity only one sixth that of Earth. That combination cannot be duplicated here on Earth, but we tried as best we could to test our equipment for those conditions. For example, because normal air conditioning is inadequate for lunar conditions, we were required to use cold water to cool the interior of our suits. We did not have any data to tell us how long the small water tank in our backpacks would suffice. NASA officials limited our surface working time to 2 and 3/4 hours on that first surface exploration to assure that we would not expire of hyperthermia.

I am, and ever will be, a white-socks, pocket-protector, nerdy engineer, born under the second law of thermodynamics, steeped in steam tables, in love with free-body diagrams, transformed by Laplace and propelled by compressible flow.

I thought, well. when I step off it's just going to be a little step — a step from there down to there — but then I thought about all those 400,000 people who had given me the opportunity to make that step and thought it's going to be a big something for all those folks and, indeed for a lot of others that weren't even involved in the project, so it was kind of a simple correlation.