Translation:This is one small step for a man, one giant leap for mankind.
Yes. But duolingo is often very literal about the translations, usually marking it wrong if you don't include the definite article. So it's very annoying when they mark you wrong for using it.
The literal translations should always be accepted, except perhaps in the rare case where it would make no sense.
I'd say even more so for idiomatic expression. Perhaps accept the answer but note the better answer.
In this case, I didn't get the question wrong because I didn't understand the portuguese or know the quote, but because I intentionally adjusted my translation to fit the expected duolingo norms.
Consistency = Usability