The Thousand Worlds

The Thousand Worlds is the setting for a series of science fiction novels written for young readers. Inspired by the 12 classic Robert Heinlein juveniles published between 1947 and 1958, Rod Walker's novels feature a young male protagonist entering the adult world of conflict, decisions, and responsibilities.
MUTINY IN SPACEALIEN GAMEYOUNG MAN'S WAR
MUTINY IN SPACE
When the radical revolutionaries of the Social Party prevent his attendance at university and make his life on New Chicago impossible, Nikolai Rovio has no choice but to accept his starship-bound uncle's offer to take refuge in space and sign on as a technical apprentice with Starways. But space, he quickly learns, is full of dangers that can kill a young man just as dead as even the most bloodthirsty revolutionary. And no place that Man can travel can ever truly serve as a safe refuge from ambitious and evil-minded men.
ALIEN GAME
Sam Hammond might have chosen prison if he'd known that instead of being locked up, he'd find himself working security for a safari colony on a jungle world where the herbivores are the size of a stadium, the apex predators are vicious lizards that can turn themselves almost invisible, and the skies are filled with huge, acid-breathing fliers. But when New Princeton's Minister of Ecology arrives for a visit with a spaceship full of wealthy and powerful guests, Sam discovers it is Man that is the most dangerous animal on the planet.
YOUNG MAN'S WAR
¿¿When the Dark Gates open and unleash the monstrous Darksiders on an unsuspecting Earth, only the toughest and most determined humans will survive. Roland and Maggie Kane are more fortunate than most, because their father, Daniel, is a Chicago cop who has taught them how to shoot and prepared them for almost every eventuality. But, as the Kane family soon learns, there is just no way to prepare for an alien invasion.