Those party poopers at Snopes has declared this urban legend a myth as verified by the NASA transcripts. Nonetheless the facts should never get in the way of a good story:
When Apollo Mission Astronaut Neil Armstrong first walked on the moon, he not only gave his famous "One Small step for Man, One Giant Leap for Mankind" statement but followed it by several remarks, usual com traffic between him, the other astronauts and Mission Control.
Just before he re-entered the lander, however, he was supposed to have made the enigmatic remark "Good luck, Mr Gorsky." Many people at NASA thought it was a casual remark concerning some rival Soviet Cosmonaut. However, upon checking, there was no Gorsky in either the Russian or American space programs.
Over the years many people questioned Armstrong as to what the "Good luck Mr Gorsky" statement meant, but Armstrong always just smiled. A few years back, while answering questions following a speech, a reporter brought up the old question to Armstrong. This time he finally responded.
Mr Gorsky had finally died and so Neil Armstrong felt he could answer the question. When he was a kid, he was playing baseball with a friend in the backyard. His friend hit a ball which landed in the front of his neighbour's bedroom windows. His neighbors were Mr & Mrs Gorsky. As he leaned down to pick up the ball, young Armstrong heard Mrs Gorsky shouting at Mr Gorsky.
"Oral sex! You want oral sex?! You'll get oral sex when the kid next door walks on the moon!"