Unmissable and attainable through the gradual progression through the story. Chronologically, the achievement should be the next story based achievement you get after you get
Mission Details [Marooned] (verbatim from game):
*** Spoiler - click to reveal ***- Borrow the Orbatron for an unspecified amount of time. (Like, forever.)
Now that you've got a vehicle, you just have to figure out how to get into Concordia proper. Janey mentioned that she had something that might help -- go grab it, then hop in a vehicle and head out on a not-uneventful journey.
Turn In: Springs.