In 2112, humanity has spread across the solar system, and peace reigns as the world turns its' eyes outward. The moon is dotted with dozens of permanent research bases. Millions call the domes of dusty Mars home. Humans soar above Venus's caustic atmosphere, and eke out a living amongst the rings of Jupiter and Saturn. The challenges of the solar system has been met, and tamed. Which left only the stars.
The UNOOSA Legatus is the path to the stars. Built by a consortium of space agencies under the direction of the United Nations Office for Outer Space Affairs, the Legatus is the largest mobile structure built by man. Designed to carry 15,000 colonists to Gliese 581, it has taken 20 years to construct. But after two decades of work it is finally completed. Most of the berths on the Legatus are given away to workers and scientists that would be necessary to establish a self sufficient colony light years from Earth, drawn from all nations of the world. Other berths have been given over to those that worked on the Legatus, or those that were simply rich enough to pay to leave the solar system. The remainder are given by lottery to those brave or desperate enough to want to leave, to appease those that claim the Legatus is just a rich man's toy.
The trip to Gliese would be long, and one way. Even with the most powerful engines designed by man, it would take centuries for the Legatus to cross the light years, and much of the ship was designed to be cannibalized to help establish the colony. Laying down in your stasis bed in far solar orbit, you know that it would be the last time that your eyes would see your home system. But humans had always been eager to step over the last frontier into a new unknown.