Known Space is the setting of many of
Larry Niven's
science fiction stories.
The Known Space stories span approximately a thousand years of history, from the first human explorations of our solar system to the colonization of dozens of nearby systems (and with references to events some billion years ago!).
Warning: Wikipedia contains spoilers
In the process, humankind encounters several intelligent alien species,
including:
- Pierson's Puppeteers[?], a technologically advanced race of three-legged, two-headed creatures descended from herd animals, and noted for their cowardice;
- the Kzinti[?], belligerent giant cat-like aliens with whom the humans fight several brutal wars -- mostly offstage until the release of the Man-Kzin Wars short-story collections, largely by other authors;
- the Outsiders[?], low-temperature fragile aliens that trade information and cruise deep space;
- the Thrintun, a long-extinct species which ruled the galaxy through telepathic mind control;
- the Pak[?], interstellar relatives of humanity whose life-cycle evidences the purpose of human old age;
- the Kdatlyno[?], a blind species who see by way of sonar and create sculptures intended to be touched;
- the Bandersnatchi, colossal sluglike creatures, originally grown as a food source by the Thrintun;
- the Tnuctipun[?], used by the Thrintun as genetic engineers;
- the Trinocs[?], who have a culture based on gambling;
- the Martians, now extinct;
- the Grogs[?], sessile furry cones, which can control animals telepathically.
Also figuring in some stories are intelligent cetaceans and various offshoots of Homo sapiens lineage.
An amusing and interesting aspect of the Known Space universe is that most of the planets colonized by humans are suboptimal for Homo sapiens
(They were declared habitable by dumb robot probes and then colonized by generation ships):
- Plateau in the Tau Ceti system is Venus-like, with only a California-sized plateau rising high enough into the atmosphere to be habitable
- Jinx, orbiting Sirius, is a massive moon of a gas giant, stretched by tidal forces into an egg shape and with gravity near the limits of human habitability. The poles lie in vaccuum, the equatorial regions Venus-like (and inhabited by the dinosaurian native "Bandersnatchi"); the zones between have atmosphere breathable by humans. Jinx's poles become a major manufacturing area.
- We made it orbiting Procyon, got its name because the first colony ship crash-landed. The planets axis is pointed along the plane of the ecliptic, creating ferocious winds during half of the planets year, forcing the people to live underground.
- Warhead was an uninhabitable Mars-like world, until hit with an experimental weapon which tore a kilometers-deep hole into the crust. Most of the planet's atmosphere fell into this artificial crater, resulting in a breathable environment, and the planet is renamed Canyon and settled by humans.
The series also features a number of "gee whiz" inventions which figure as plot devices, including invulnerable starship hulls, transporter booths (used only on planetary surfaces), the lifespan-extending drug "boosterspice", and the "tasp" which is capable of stimulating the pleasure centers of the brain from a distance.
The milieu can be viewed as representing the climax of the pre-cyberpunk era of science fiction, as the cyberpunk themes of information technology and competition of various sub-governmental groups do not figure in the stories.