Placing his [Armstrong's] left foot on the surface at 2:56 UTC July 21, 1969, he spoke the following words:
“ That's one small step for (a) man, one giant leap for mankind. ”
It had long been assumed that Armstrong mistakenly had omitted the word "a" from his famous remark ("one small step for a man), rendering the phrase contradictory. Armstrong, who admits that he often forgot syllables when speaking, is quoted as saying that he "would hope that history would grant me leeway for dropping the syllable and understand that it was certainly intended, even if it wasn't said—although it might actually have been." Listening to the audio seems to reveal that the "for" runs on smoothly, giving no time for "a" to be spoken.
It has since been claimed that acoustic analysis of the recording reveals the presence of the missing "a". A digital audio analysis conducted by Peter Shann Ford, an Australia-based computer programmer, claims that Armstrong did, in fact, say "a man", but the "a" was inaudible due to the limitations of communications technology of the time. The article by Ford, however, is published on Ford's own web site rather than in a peer-reviewed scientific journal. ... Armstrong has expressed his preference that written quotations include the "a" in parentheses. The simple statement came from a train of thought that he had during the hours after landing. He knew he would have to say something as he took the first step, and "step" seemed like a good place to start. It just grew from there. Theories that he consciously took the statement from J. R. R. Tolkien's The Hobbit ("not a great leap for a man, but a leap in the dark") or a memo from an associate deputy administrator of NASA are denied by Armstrong.