Amy, in the final scenes of SHADES OF EARTH, by artist Aghnia Mardiyah, who was only 17 years old at the time! http://amardiyah.tumblr.com/post/42710181464/and-then-we-see-the-end-there-is-against-the Spoilers for the end of SHADES OF EARTH in her description.
In the ACROSS THE UNIVERSE series by Beth Revis, Godspeed is a vast spaceship, the size of a small country. The lives of its passengers are severely regulated. And people are divided into three categories–Feeders, Shippers, and Keepers–represented by the three levels of the ship.