Back in 1969, a certain Neil Armstrong stepped down form his spacecraft and was the first human to place his foot on the surface of the moon. As he did so, he made the famous statement "One small step for man, one giant leap for mankind."
The original high resolution recording of that moment in history has been lost. But don't worry, NASA has lots of (inferior quality) copies.
Here is one such source for you to relive the moment. You will need RealPlayer. In all honesty, the sound isn't that great, but then this is a copy!
But wait, there's more! This 38 MB Quicktime movie covers Armstrong's entire descent onto the surface of the moon. Quite anti-climactic in this rendition as the shouts and cheers at Mission Control are not on the soundtrack!
Now for a possible reason why the original magnetic tapes are missing. Sometime between then and now the movement for sexual equality demanded that Armstrong's rehearsed statement is discriminatory. Armstrong represented all humans, not just men. So, in this crazy PC world we live in, it is entirely possible that someone in NASA simply dumped the tapes in a fit of chagrin.