I have been plowing my way through the science fiction novels of David Weber which concerns a character named Honor Harrington who is a starship captain for Manticore. This is typical space opera fare but differs from that of Star Trek in that these are descendants of people who fled earth to establish their own settlements. Earth in these novels is seldom mentioned and is not a factor, and does not show up in the novels with any regularity. Nothing takes places or earth nor are there any journeys or connection to earth. Indeed their whole calendar is dated post diaspora dealing with how many years they have been from earth. Earth, I believe, is somewhere in the 3900's AD but the Manticorian calendar is only in the year 2000, or something like that.
Aliens do not appear in great regularity in these novels, unlike Star Trek or Star Wars. The principle activities takes place between two rival human factions, The People's Republic of Haven, and the Manticoran Star Empire. The People's Republic of Haven is a liberal democracy which operates on deficient spending because of the fact that it foolishly placed its entire population on a stipend so that nobody has to really work in order to starve off dissent and revolution. Because of that fact the PRH must always expand outward, start wars, and find new sources of revenue. If they reminded idle their empire would collapse.They must always use foreign escapades to incite the masses into war in order to divert divert their attention from domestic issues. Does that remind you of a certain nation in our reality? Perhaps the United States?
The rival to the PRH is the Manticorian Star Empire which is a constitutional monarchy. I thought at first the author had to be British as Manticore is like the British Empire at its height and glory and the PRH is the United States in its present form. (Deficient spending, massive welfare, constant international interventionist escapades.) But, alas, he is an American. Honor Harrington is the main character in all the novels and was recently knighted for her service to the Queen so she is now Dame Harrington. She is the commander of the HMS (Her Majesty's Ship) Fearless and later the HMS Nike after the Fearless was destroyed. She always has a tree cat with her, a six legged tree dwelling feline capable of bonding with its owner and reading its owners thoughts. Starships in the Royal Manticoran Navy are massive with many being 1 and1/2 kilometers. (Thats about 5850 feet- a mile being 5280 feet) That is much more massive than ships in the United Federation of Planets in the Star Trek universe.