D.A. by Connie Willis
Some high school kids would do anything to be an IASA space cadet, but not Theodora Baumgarten in Willis's cheerfully tongue-in-cheek SF novella. "There's no air, you're squashed into a ship the size of a juice can, and it takes years to get anywhere interesting. If you... aren't killed first by a meteor or a solar flare or a systems malfunction." But somehow, without submitting an application, Theodora is accepted to the Academy. Soon, she's green with space sickness aboard the Academy space station (named, appropriately enough, the Robert A. Heinlein), learning the ropes with a class of robust, gung-ho cadets. Getting out will require solving the mystery of how she got into the Academy in the first place, but it might have something to do with the annotation "D.A." in her station records.
This is a very short novella - maybe 50 pages including several full page illustrations by J.K. Potter. But I do love Connie Willis even in such a brief form. I do wish a longer novel would come out or do like Charles De Lint and publish her stories in a collection. I'm thankful I can find her books at the library as it would get expensive to purchase each one on it's own no matter how lovely they are. This was a fun read and I liked how she is writting for a younger audience as we need good science fiction for teens and tweens.