“a” is an indefinite article, not a preposition. Prepositions are how a verb relates to an indirect object. “The bunny hopped over the fence, around a tree, and down a hole.” The italicized words in this sentence are prepositions. In, on, at, near, etc… You get the idea…
Anyway, the quote is kinda contradictory without the “a”. Is it a small step or a giant leap? Oh, it’s a giant leap for mankind, and a small step for a man. Makes so much sense now.










Nah, give him shrooms and let the mushroom gods show him the weight of his own soul as it drags him beneath the rising tides of the abyss…