Space Cadet is the second of the Heinlein juveniles (published in 1948) and is often considered to be one of the best in the series. Certainly the strong story and the vivid characters always make for a pleasant afternoon.
However, the oddest thing about re-reading Space Cadet this afternoon was the contradictions with some of the later juveniles.
To start with the smooth and logical progression of the storyline makes it hard to pick any breakpoints for serialisation. Certainly it it is much harder to pick the breakpoints in Space Cadet than in either Farmer in the Sky or The Rolling Stones, enough so that I'm not sure that it was serialised prior to publication as a novel.
The gender balance (or staggering lack thereof) is the other great contradiction with the later juveniles. The Space Patrol is a purely stag affair and the few references to females are far removed from the ladies of the Stone Gang. To be blunt about it, in Space Cadet the occasional females are decorations, in The Rolling Stones they are characters with tough academic qualifications of their own (in descending order of age: Nuclear Engineer, Doctor/Surgeon, Pilot).
This is not to say that Heinlein always got this right (as I recall Starman Jones had some nasty gender based clangers in it). However, generally from Farmer in the Sky onwards, the juveniles usually had at least one female character worth mentioning and/or challenged 1950s attitudes to gender roles.
Space Cadet is also the Heinlein with one of the best examples of socialising predicted technology. It is (relatively) easy to predict something, it is harder to predict how something will impact the people using it. In the first chapter Heinlein not only predicted mobile phones but that users would often resent or try to hide them. In an impressive display of clarity and brevity Heinlein also managed to communicate the existence of the technology and the attitude in less than half a page.