Though we knew long before this date that the earth was round and revolved around the sun, this event nonetheless was the culmination of an exhaustive journey that began with the will to dispel those Bronze Age theories. It also proved the moon wasn't made of cheese, which may sound silly, but many people believed that as fact, which is no more silly than an all-knowing being in the sky watching your every move and listening to your every thought.
Anyway, thanks NASA for showing us we don't have to remain with our feet on the ground, and it's OK to reach for the stars.
Speaking of NASA, just to bring this back to atheism, I heard a lecture once where a story was told of American iconic astronaut John Glenn. Decades after his successful career, he was picked by NASA in 2001 to go back into space aboard the shuttle. Upon his return to space he looked down at Earth and said the planet looked so beautiful that you could tell the existence of god, or some other similar nonsense. Christians ate it up and it made headlines.
Unbeknownst to Glenn, Hurricane Michelle was making an even bigger headline, ripping through the islands and claiming 22 lives. If Glenn's loved ones were in the path of Michelle's destruction do you think he would have felt the same way? When you ask religious people about such destruction and why god would allow it to happen, they say he works in mysterious ways, absolving him of any wrongdoing. But when nature doesn't kill anyone with a twister in Kansas, for example, then god gets all the credit and is praised. Again, it's the no-lose logic that allows Christians to make their god infallible, when reason dictates it actually just proves nature is indiscriminate and god isn't in the rain.