It's the first day of third grade, and Abby Baxter is determined not to make any mistakes. It's a little trickier than it was last year, though, because Abby is starting school on the OASIS International Space Station, where her parents are scientists. Abby is so focused on getting used to microgravity, watching her little brother, Nico, and meeting her new classmates that she almost messes up Mami’s big experiment. Can she figure out how to make things right, or is she destined to be sent back to Earth?