Yep. What Neil Armstrong meant to say was, “That’s one small step for a man, one giant leap for mankind.” But that isn’t quite what he said.
The radio transmissions from the Apollo 11 lunar module were of somewhat poor quality. If you listen to a tape of the transmissions, however, there can be little doubt as to what Armstrong did say. After setting foot on the moon, Armstrong pauses a second or two and says,
That’s one small step for man,
one giant leap for mankind.
The omitted “a” is a small mistake but a particularly unfortunate one. “Man” without a preceding article means not one man but man in general, mankind. So Armstrong said, in effect, that’s one small step for mankind and one giant leap for mankind. He managed to create a logical contradiction in the first eleven words spoken while standing on another planet.
The slip of the tongue is understandable. What’s harder to understand is the way the blunder has been ignored. Despite the massive buildup given the first words on the moon’s surface, no major news source seems to have mentioned the mistake, even in passing. Most newspapers and magazines at the time reported the quote accurately but without comment. The New York Times for July 21, 1969, noted,
… Mr. Armstrong opened the landing craft’s hatch, stepped slowly down the ladder and declared as he planted the first human footprint on the lunar crust:
“That’s one small step for man, one giant leap for mankind.”
Life magazine didn’t print Armstrong’s historic words, an unusual omission even in a picture magazine.
Other sources have become more charitable yet (see table). Quite a few respectable sources now give a corrected version of the line. The 1980 edition of the Encyclopaedia Britannica says,
At 10:56 PM EDT, July 20, 1969, Armstrong stepped from the “Eagle” onto the Moon’s dusty surface with the words, “That’s one small step for a man, one giant leap for mankind.”
Big Secrets’ search of reference sources found only one complete account of Armstrong’s words. This was in the relatively obscure Academic American Encyclopedia, 1980 edition (Princeton, N.J.: Aretê Publishing Company). David Dooling’s entry on Neil Armstrong gives the real story:
… he planted his left foot on the lunar surface and proclaimed: “That’s one small step for [a] man, one giant leap for mankind.” He later said that he intended to say “a,” but static on the tapes leaves this detail uncertain.