Houston wants to be an astronaut. So does his younger brother, Robbie. There's just one difference between the two of them: Robbie has cerebral palsy. Houston has promised to go to space WITH his brother, and when he's accepted into the Junior Astronaut Recruitment Program, there's a little bit of tension between the two. Houston gets to experience life with a crew, and meet his mysterious grandfather. Can Houston find a way to get his brother into space? Why does his mother and grandfather not speak? 

I think one of my favorite parts of the book is how the crew resolves conflict between them. They end up having a group conversation, and it really showed how fabulous something like that can be.