It can actually be used both ways. It only makes no sense if you percieve it as making no sense. The meaning just shifts slightly.muckinscavitch said:One small step for A man, one giant leap for mankind.
There was a error in the transmission back to earth, saying it without the A makes no sense, it would be like saying 2 is 4, 3 is 4.
I actually think of man being everyone on the earth right now while mankind is everyone now and onward into the future. It wasn't the intended meaning, but it still makes sense.