Alpha Centauri was the first new star system humans visited at the dawn of Faster-Than-Light travel. Its locality to Sol made it a natural first stop. Scientists were intrigued by the concept of a binary star and surprised to find a handful of planets in a far orbit of the two celestial bodies.
AC IV and V were closely examined and found to have no breathable atmosphere, but deemed suitable for scientific settlements. Large, pre-fabricated buildings were flown in and half-buried in the tundra environments. Early life was cold, bleak and difficult, but scientists flocked from Sol to study the new tiny forms of life discovered, the environments and the possibilities of terraforming.
The comparatively tiny arid planet of AC V was claimed by a stubborn group of Asian Coalition settlers. Although gifted with an almost breathable atmosphere, the planet had scant resources and life was hard. The colonists’ existence was only made more difficult by the turmoil and conflict of the Pan-Eurasian War.
The colonies on AC III and IV gradually expanded in size and scope. The pre-fabricated labs were easily added to and over years the settlements grew in stature. First one of the first breakthroughs in xenobiology came out of Centauri III in the form of an antibiotic developed from a hardy weed from the surface of the tundra world. And that was just the tip of the iceberg.
Scientists transported their families to live with them, necessitating schools and increased food production. This infrastructure began as a functional response, but soon people were setting up small businesses: cafes, restaurants, general stores. The capital city of AC IV, Ravensmere, was officially established. By the Third Age the Centauri System had become a place not just for science, but for people too.
Although terraforming remains a pipe dream, a group of geologists managed to detect a number of hot springs beneath the planets surface and harness them for power and warmth. In spite of what some might see as a claustrophobic cityscape of joined up structures, many have grown to see the icy Centauri worlds as their own.