Neil Armstrong, the first human being to set foot on another celestial body, misspoke his historic line. "That's one small step for man, one giant leap for mankind," as it turns out, was missing a crucial letter when Armstrong spoke it to a live audience back on Earth. What he was supposed to say as he placed his foot on the surface of Luna, the Earth's moon, was: "That's one small step for a man, one giant leap for mankind," thus highlighting the bigger picture of his small step onto the surface of the moon. Thankfully, the 600 million people watching weren't quite as pedantic as we are: The public easily overlooked the mistake, understood the meaning and let it go. Hey, the guy flew to the moon, right? Cut him some slack.

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Apollo 11 45th anniversary

WHAT IS IT?

Moon Anniversary

The Apollo 11 spacecraft is most well-known in space exploration history for being the first manned spacecraft to land on another celestial body. It carried three American astronauts to the Earth's satellite in 1969: Neil Armstrong, Edwin "Buzz" Aldrin and Michael Collins. In fact, yesterday marks 45 years since Armstrong and Aldrin stepped out of the ship and onto the moon.

The spacecraft itself was divided into three components: living quarters (which came back to Earth with the three astronauts), a service module (which supplied propulsion, electricity and oxygen) and a lunar module (the crazy-looking shuttle that brought Armstrong and Aldrin from lunar orbit onto the surface). We're focusing on the living quarters ("Columbia") and the lunar lander ("Eagle") in this piece.

The massive, American-built spacecraft -- by which we mean "all three parts of Apollo 11 together as one ship" -- weighed just under 100,000 pounds. A single Saturn V (pronounced Saturn "five") rocket carried the hulk of metal (and three human beings) into space, and staged detonations enabled that rocket to propel Apollo 11 into lunar orbit.

After eight days -- from takeoff at Kennedy Space Center in Florida to splashdown in the north Pacific Ocean near Wake Island -- Apollo 11's command module (where the astronauts lived while aboard) returned to Earth. The lunar module ("Eagle") was left in lunar orbit and is believed to have crashed into the surface in the following years.

WHY SHOULD I CARE?

Moon Anniversary

Apollo 11's mission to bring the first human beings to Earth's moon was the effective end of the so-called space race between the Soviet Union and the United States. After years of both superpowers dumping resources into said race, Armstrong's "giant leap for mankind" definitively declared victory for the United States.

More importantly, the Apollo 11 landing signaled the opening of the next frontier for human exploration. Without the Apollo program, Elon Musk's SpaceX and Richard Branson's Virgin Galactic might not exist. The International Space Station, launched as a joint effort between 15 partner nations (including the US and the post-USSR breakup Russian Federation), might not exist. Heck, Star Wars might not exist. And we're quite partial to Star Wars.

But beyond the whole "glory of human advancement" business, the act of putting three human beings on Earth's moon -- safely -- and then bringing them back home -- again, safely -- in 1969 is... somewhat unfathomable. We're 45 years out and humanity remains far from the concept of commercial space flight.

China just last year landed its first unmanned rover on the moon. In 2013. That isn't intended as an insult to China, but to say, "Hey, seriously, it's really hard to launch a spacecraft and land it on another celestial body."

WHAT'S THE ARGUMENT?

It's not much of an argument given that it's been proven wrong over and over, but a group of folks claim that the Apollo 11 moon landing was faked on a soundstage. Those same folks argue that all subsequent moon landings were faked as well.

Per the Apollo 11 landing specifically, the argument is that certain photos taken on the moon show shadows that don't go in the same direction. So the logic goes: Multiple shadow directions, multiple sources of light (which is to say, "more sources of light than just the sun"). Mythbusters took on this theory in a 2008 episode, seen in part below:

There are myriad other theories, zero of which offer credibility to the side of the doubters.

WANT EVEN MORE?

And who wouldn't? The moon, and space travel in general, has fascinated human beings for centuries. For more on the Apollo 11 mission specifically, we suggest you check out Tom Wolfe's excellent book on NASA's ambitious plan to put human beings on the moon: The Right Stuff. Oh, you'd prefer a movie? That exists as well, and it's also really good!

For a less bombastic approach to the Apollo 11 landing, we suggest How Stuff Works' excellent piece on lunar landings, as well as Stuff You Should Know's podcast about the same subject. There's kind of a lot of material out there on the Apollo 11 landing considering it's one of humanity's greatest achievements, including books from the astronauts themselves and countless tales from NASA scientists involved in the project. We're barely scratching the surface here, so we suggest digging in on the history and branching out from there. You could spend a lifetime just studying the Saturn V rockets that propelled many American spacecraft into orbit.

[Image credit: NASA (Buzz Aldrin on the moon, moon landing video, Apollo 11 launch and lunar module); Alexis Santos/Engadget (SpaceX); "Mythbusters" S6/Ep. 11; The Ladd Company (theatrical trailer for The Right Stuff)]