I gave this book 3 stars when I first read it a couple years ago. After rereading it just now, I have to say it only deserves 2 stars. And I'm not even sure about going that far.
Space Junque is the first part of the Apocalypto series. And I use the word "part" because it's not really a complete story. You're obviously supposed to read the next 2 books if you want to understand what the hell is going on. The only thing you can really take away from it is "not everyone dies"... And that's about it.
Too many things are unexplained. Not in the cliffhanger sense, but in the sense that you have no idea how things happened. People are in this speshul city, but it's never explained how they got there. Or how it's safe in comparison to the rest of the planet that has pretty much been nuked to nothing. I reread a few paragraphs about a dozen times before giving up on understanding what was going on. The author does a poor job of segueing from one scene to another. And by "poor job", I mean "none at all"...
Since I haven't read (nor do I have any plans to) the next 2 books, I can't fully comment on the plot. It floundered for a bit at the beginning and I really couldn't figure out where it was going. About the time I got to the "give up or give in" point, things took a turn for the wacky and suddenly it's a mythological story. Not the space opera it was pretending to be. Then it got even weirder with little 8 and 9 year old girls being breeders. And then it was over.
I wouldn't recommend this. It doesn't really make sense.