Books written about the future inevitably at some point become alternate histories. First published in 1948, "Space Cadet" builds a post-2100 solar system where Venus is not only habitable, but inhabited, where Mars and Ganymede are colonisable, and spaceships are rocket-shaped and can take a couple of years to travel between planets.Military academy stories share many of the same beats and cadences of boarding school and wizard school stories: newcomer arrives at school, gains an antagonist, builds lifelong friendships, hovers between overwhelmed and over-achiever, increases in competence and then usually encounters a challenge "out of their pay scale", something which adults would normally deal with, but which circumstances mean that the student and his or her plucky band of friends must deal with themselves."Space Cadet" hits these notes without any really surprising turns. Our plucky newcomer, Matt, is a sample of a fine and upstanding young man – modest, enquiring, honest to a fault. And that's fortunate indeed because he's trying to qualify for an organisation which emphasises intellectual exceptionalism as a means of creating people of higher moral fibre – people who have the responsibility of keeping the peace in a post-nuclear war world, and who are entrusted with the maintenance and control of a large number of nuclear weapons, ready to enforce that peace in a nuke-the-site-from-orbit fashion (which fortunately hasn't been necessary for many years). The science, the quest for knowledge and understanding while living up to a valorous tradition, is the meat of the story.There's a strong emphasis in the story on not being racist – with careful displays of the multicultural nature of the Patrol, as well as a need to respect local customs, including the customs of the inhabitants of Venus, who become tangled in the end-game of the story. On the whole, for its time, "Space Cadet" is quite a forward-thinking novel in its intentions. At the same time, this is a multiculturalism filtered through a very American channel. The values of the Patrol are extremely American, the academy is based in the US, the universal language 'Basic' is a simplified variant of English.And then, of course, there are the women.The blurb of my edition of this book (published in 1969) tells us "The story is about the young men who are training to be officers in the Interplanetary Patrol … and reaffirms the glorious interplanetary traditions of bravery, resourcefulness and revolutionary brotherhood."There are no women in the Patrol. None in the Academy. Indeed, for a while I thought there'd be no women in the book, beyond a couple of glimpses of attractive females not relevant to the story, and given the way early Heinlein talks about women I considered this not necessarily a bad thing. [The Patrol is not primarily a combat organisation - there's Space Marines for that kind of ass-kicking. Qualifying for the Patrol requires smarts, nerve and morals, not physical strength.]When our young hero goes for a home visit, about a year into his training, we glimpse the women in this universe and perhaps understand why they aren't in the Patrol. The purpose of the visit is the "you can't go home because you are no longer the same" message often encountered in bildungsromans – with an emphasis on the intellectual and general superiority of people in the Patrol.Then we meet Matt's former not-quite-girlfriend, and learn that she appears to have moved on from him romantically, but Matt considers that no real loss because "Marianne was the sort of girl who never would get clearly fixed in her mind the distinction between a planet and a star."Indeed. A girl who can't be brought to understand the difference between "like the Earth" and "like the Sun" is probably not life-mate material. One would wonder if she would even be able to tie her shoelaces.We then move on to Matt's mother, who is apparently incapable of understanding just what it is her son has gone off to join, let alone grasp the concept of "orbit", and displays the nervous temperament and intellectual capacity of a flustered chicken. [Matt's brother and father fare only slightly better – they are Earth-bound and non-exceptional.]There are better females to meet later, however. The Venusians are a female-dominated society with a highly advanced chemical-based technology, and who become part of the book's message of honouring local customs and cultures. Of course, they're also peace-loving "Little People" who outwardly appear primitive, are incapable of understanding the concept of war, don't actually believe that stars exist (because of the clouds on Venus, y'know) and are kind of nags ("they don't fight; they just argue until somebody gives in". They're still given considerably more respect than any human female in the book, so it's not all bad in Lady-Land.