instead of loopholes, consider openings, gaps, or escape routes.  Loopholes is too broad of a word because of the more common legal definition.   Also an appendage(s) is either a body part or a hanging attachment--not sure if this is the best word here.   An appendage of what?    human, mechanical etc.  Name the main device or structure.  You spoke of a southern appendage, but you still need to identify what the hanging attachment is attached to in the same sentence. If you described the target earlier, I don't recall. If you are referring to a fortress,  it has walls, parapets, towers, bulwarks, barricades, ramparts and embankments. There are other words for attachments to devices in space.   If you are referring to a giant robot or an alien creature, then appendage is fine. 

Let us now summarize, -->  let's summarize.    Let us now, sounds too formal, almost pious. now, is unnecessary.  Keep the original if the character is intentionally formal and pious. 

we are and everything is For

range -->  three billion (light) years

"pricked" up their ears  -->  perked