(from their old website) In 1964 there were several secret launches from NASA that had the People of Ethical Treatment of Animals (PETA) completely up in arms. NASA was using monkeys to fly space missions and spy on russian missile silos. In June of '64, 5 simians were launched on what NASA thought was a regular "Spy Monkey" Mission but something went wrong. Well, needless to say at this point the monkeys were out of control and headed toward the dark side of the moon. A band called Pink Floyd wrote a tribute album to these monkeys a few years later and called it "Dark Side of The Moon."