The first human beings to see the "dark" side of the moon were not astronauts. As everyone from grade school children to Pink Floyd can tell you, there is no dark side of the moon, really--just the far side that is forever turned away from the Earth. During all history, while the familiar man-in-the-moon side was observed and charted and depicted in art and song, the far side remained a total mystery.

That changed in October of 1959, when the Soviet Union dispatched a small probe called Luna 3. The spacecraft was in some ways simple by today's standards, but it carried a remarkably ambitious set of machinery. Cameras that were pointed toward the moon exposed rolls of film, which were automatically developed right on board the spacecraft, then scanned so the electronic information could be beamed back to Earth by radio. The team working on that mission included the first people to see the grainy images that revealed the far side for the first time.