(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.
The monkeys took control of the capsule and headed towards our moon. Since this mission was top secret, NASA kept it quiet to the entire world that there were monkeys heading towards the MOON…. Even the PETA protestor's were unaware of this mission as they were paying close attention to the useless slaughter of Panda bears in High Schools and churches around the world. (It seems there were people using the fur from these innocent animals as chest hair for their children).
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."