How to correctly say this in Latin?

'audacter ire' = to boldly go ('to go' in the original is an infinitive and should be translated as such)

'finis ultimus' (or 'terminus ultimus') = the final frontier

ultimus = farthest, most remote, uttermost, extreme, final

audacter = boldly, courageously

Here's the whole thing just for fun:

"spatium, finis ultimus, hae sunt navigationes astronavis Enterprise, cuius legatio quinque annorum: explorare alienos et novos orbes, quaerere novam vitam et novos cultus, audacter ire quo nemo antea iit."

Edit: I just had a thought. I can't recall the exact sound of Kirks little speech, but if he emphasises the word final, then "ultimus finis" might be better.