Before the Apollo launch, von Braun was asked what the reliability of the rocket was. He asked 6 of his lieutenants if it was ready to fly. Each replied "nein". Von Braun reported that it had six nines of reliability.
The joke that made the rounds of NASA was that the Saturn V had a reliability rating of .9999. In the story, a group from headquarters goes down to Marshall and asks Wernher von Braun how reliable the Saturn is going to be. Von Braun turns to four of his lieutenants and asks, "Is there any reason why it won't work?" to which they answer: "Nein." "Nein." "Nein." "Nein." Von Braun then says to the men from headquarters, "Gentlemen, I have a reliability of four nines."
