Another Heinlein novel read! This one's from 1948. It was his second juvenile, after Rocket Ship Galileo. I hadn't read it in a very long time, and I was surprised by what I remembered. Almost nothing about the plot, but I did remember "pie with a fork". (I'm sorry, not gonna explain that, you'll have to read it yourself.)
It is set in an alternate future, and (as it turns out) an alternate universe, one in which Venus is inhabitable, and has intelligent native life. Interplanetary travel is common, and humans have presence on the inner planets, Ganymede, and the moon. And Space Patrol is a "peacekeeping" force, accomplished by its monopoly on atomic weaponry, to be dropped from orbit on any sufficiently troublesome provinces.
The protagonist is Matt Dodson, and we follow his Space Patrol career: applicant, lowly plebe, trainee, and, eventually, a participant in critical missions. Things wind up with a life-threatening rescue operation on Venus, where surprising things are revealed about the native culture.
Practically no women. At least not human women. Matt's mom (who's kind of a ditz) shows up on a few pages, and his girlfriend is talked about.
You can see faint premonitions of Starship Troopers, as the operations and structure of Space Patrol get explained didactically.
Sadly, the Clifford Geary illustrations I remember from my youthful reading aren't in the Kindle edition I bought.