In this case SF can also mean Satirical Fiction. This is very funny and those that avoided it because it’s SF, their snobbishness caused them to miss a very entertaining read.
Humanity exploded out into space and settled on various planets. It’s four hundred years after the great explosion and a starship loaded with crew, military and bureacrats has been launched. The object is to unite the planets against a possible alien invasion. There’s never been an indication that there will be one. There’s also no indication that aliens even exist. That doesn’t stop them. They’re supposed to visit four planets.
The first port of call is a planet where a million criminals were sent. Now it’s divided into Keeps and Strongholds. The population relies on trade and avoiding work at all costs. The military doesn’t fare well.
Now it’s off to Hygeia. A group calling themselves the Sons Of Freedom went there along with The Naturists. The two groups never got along and the Sons Of Freedom are dying out. The starship lands in Naturists territory. They demand the starship population act as they do. They’re nudists. This part of the book is hilarious.
The third planet is deserted so it’s off to the fourth and final stop. This planet doesn’t have a name. All they know is that it was originally settled by dissidents. When they land, no one wants anything to do with them. There’s no central government and even the fire department doesn’t have a chief.
A storekeeper says they have the perfect weapon and he’ll give it to them for nothing. Some of thr troopers finally catch on.
For sheer entertainment, look for this one.