In the early 2040s, humans took their first steps on Mars.
In the decades following, they began building stations in orbit, allowing for the refill and restocking of starships traveling from Earth without the need to touch down. These massive leaps in humanity's capability for interplanitary travel brought humanity into a new age of exploration. And of colonization. As is the nature of humans, this led to conflict. Within the next century the price of starships dropped as low as a house, allowing curious citizens to form their own rogue factions and explore.