Around 50 years after the first Mars missions and the Cassini's Grand Finale (https://www.youtube.com/watch?v=xrGAQCq9BMU), Nasa develops the SoFOS program. The original idea was to study plantes and satellites that seem to allow the developing of any form of life. The Cassini_03 (2067) detects a small galaxi with a similar system to ours, where a little planet contains, apparently, water and vegetation.
This earth-like conditions fuel up the science community imagination, and ideas that until now were only developed in the film industry, are now taken seriously by the scientific community. The planet will be called UAINOT.
During the 2070's, first explorations with robots and artificial satellites are made (3 of them are still in orbit today). These allow to corroborate the viability of establishing a colony of scientists, and by 2084, twenty of them arrive with equipment to establish themself. A scientific base, machinery to process water, solar panels and a communication structure are build on the surface.
Today, 43 years after the arrival, the scientific expedition is a fully established colony, with over 800 scientists and another 5 stations.