Bradley Martin

This story, thankfully, does not hold up as well as some science fiction, but for me it came at the right time.
When I was in middle school our library was selling off some of their older books, and the third book in this series was there (End of Exile). I picked it up on a whim and was in love with it instantly. The mystery of what happened to the ship, the discovery of seeming ancient technology and an exciting finale, mixed with a bit of mildly disturbing elements had me in love. I quickly went back and bought the other two as well.
I am a sucker for a story that leads to discovering ancient secrets that lead to a slow rebuilding, or rediscovery of purpose.
The City and the Stars, City of Ember, this series, and Battlefield Earth all fit this bill and they're all great reads.