Space Cadet (1948) – Matt Dodson enrolls in the Patrol military academy, learning how to service the atomic weaponry in orbit that enforces peace on earth and to assist in diplomatic, technical, and civil engineering projects between the planets of the solar system.
For more information on Heinlien's Juveniles (written between 1947 and 1958) see our entry on Robert Heinlein's Rocket Ship Galileo, The Literary Encyclopedia profile by William Patterson, University of California, Santa Cruz
Patterson, William. "Space Cadet". The Literary Encyclopedia. First published 10 November 2004
[https://www.litencyc.com/php/sworks.php?rec=true&UID=16272, accessed 23 April 2018.]