This is the second of Heinlein’s “juveniles,” a series of books for younger readers, first published in 1948. With it, he hit his stride in the series, producing a fine story with well-integrated scientific and moral themes and appealing characters.

As the book opens, Matt Dodson is reporting to a center in Colorado as a cadet trainee in the Interplanetary Patrol, an organization which acts as a police force and deterrent throughout the solar system of the year 2075, a solar system which includes several colonies on other worlds. The Interplanetary Patrol controls a satellite-based nuclear weapon system that acts as a deterrent to war and conflict on Earth and elsewhere. As the story develops, we learn that cadets must be willing to put their loyalty behind the Patrol over their home planet, home country, and even family. Matt is soon befriended by cadets Tex Jarman from Texas, Oscar Jensen from Venus, and Pierre Armand from Ganymede. Their training is a winnowing process where they must pass many kinds of tests, both physical and mental, and the large class of trainees gradually dwindles. Those who are deemed space-worthy continue training on the school ship James Randolph in permanent orbit around Earth.

The training process is well told, based on Heinlein’s own training in the U.S. Naval Academy but with additional challenges like weightlessness, space navigation, and the airless vacuum of space. Matt’s path is not always easy, and he considers leaving to become a Space Marine, where battle and glory are the goal, while a roommate opts for the Merchant Service, dedicated to commercial shipping. In the end he stays with the Patrol and is assigned to a working Patrol ship, where he must learn more. His first mission is to the Asteroid Belt in search of a missing ship. Later he is part of a mission that lands on Venus, where the training and skills of Matt and his friends are put to a real-life test dealing with angry natives, and their landing craft is lost, sinking into the swamps of Venus.

I enjoyed this novel just as much this time as when I first read it as a boy. I had no interest in a military career, the closest I came to the kind of experiences Heinlein describes was being in the Boy Scouts for a few years, and I wasn’t particularly good at that, though I liked some things about it. Even though the military life was not for me, Heinlein makes it understandable and appealing through his skillful writing, and the moral choices presented to the characters are ones I understood and appreciated. The science and glamor of space travel is well represented, even though it’s now largely outdated by modern computers and technology. It feels real, and there are a few prescient hits, like the use of cell phones. Heinlein’s title, “Space Cadet” led to an unrelated TV show and successful media property, “Tom Corbett, Space Cadet,” which never had the appeal of this book for me, and the phrase became common in our language, though not always with positive meaning.

Recommended, and a good place to sample Heinlein if you haven’t before.