Who was the first man to walk on the Moon?

Neil Armstrong, on 20 July 1969, followed about twenty minutes later by Buzz Aldrin. The landing was closer to failure than the broadcast suggested: the guidance computer threw alarms it had no time to explain, the automatic system was steering them into a boulder field, and Armstrong took manual control and flew on with about seventeen seconds of fuel remaining.

The computer alarms turned out to be the system working as designed. It was overloaded and shedding low-priority tasks to keep the essential ones running - an approach called priority scheduling, unusual at the time, and largely the work of a team led by Margaret Hamilton, who also coined the term software engineering because nobody was taking the discipline seriously.

The famous line is disputed by the man who said it. Armstrong maintained he said one small step for a man, which is the only version that makes sense - man and mankind otherwise mean the same thing and the sentence contradicts itself. The recording is ambiguous and audio analysis has gone both ways. He was, by every account, a genuinely reticent man who found the fame uncomfortable and spent much of the rest of his life teaching engineering in Ohio.