Michael Dahl 
Beyond the Furthest Star [PDF ebook] 

Zak Nine and his Quom friend, Erro, are desperate to get off planet Alcatraz. The boys believe they’ve finally found a way to freedom when they join up with another prisoner. Together with their new partner, the boys board a small spacecraft and fly off the planet, past the metal moon, and head into space. But when the stars begin to look strange, Zak and Erro realize that something is very wrong. What will happen when the boys learn Planet Alcatraz’s biggest secret? Will they ever be able to return home?