Project Diaspora was a privately-funded interstellar colonization mission carried out by the passengers and crew of four space arks. The project director's vision was for the prospective colonists to flee the growing destabilizing solar system as the cold war between the Moon and Mars was reaching its apex.
THE INTERPLANETARY COLD WAR: Following the end of the two Belt Wars, the governments of the Moon and Mars became embroiled in a perpetual cold war. Though tensions between the two star nations had always been adversial after the end of the Second Belt War, the tensions became increasingly more heated. (2140+)
PROJECT DIASPORA/OPERATION EXODUS: Eccentric trillionaire Vikram Salam of Praxis Astronautics becomes increasingly terrified by the cold war between the Moon and Mars. Fearing the proverbial “end of the world,” he constructs four colony ships carrying 20,000 people in hypersleep for decades-long transits to nearby potentially habitable worlds. Each ship is named after pioneering rocket scientists. The project took nearly a decade to fully realize. (2154-2164~, launches held throughout the year 2165.)
ZERO HOUR/DEPARTURE/PHOBOS CRISIS/PHOBOS CONFLICT: Tsiolkovsky, Korolev, Goddard and Oberth depart the Earth-Moon system for their respective worlds. The Goddard and Oberth are destroyed en route, only the Oberth departed the Solar System when there was relatively calm conditions in the Solar System while Commander Beach mutinied against the powers that be and traveled toward his target of Seligman 505. The Phobos Crisis, as it became known, came about due to a Lunarian military spacecraft being withheld by a Martian port. When the Martian military destroyed and murdered the crew the stage was set for a full-scale conflict which nearly lead to the destruction of both the Martian and Lunarian societies. Luckily, diplomacy won out in the end. (2165)
FALL OF THE FREE MARTIAN REPUBLIC/RISE OF THE LUNARIAN COMMONWEALTH: By 2170, the Free Martian Republic collapsed and the Lunarian Commonwealth was left the sole power in the Solar System. A few decades passed before the newly formed Terran Alliance began construction and launches of a dozen new interstellar colonial transports using antimatter propulsion, seven times faster than the nuclear fusion/fission engines of the past.
INTERPLANETARY SOCIETY AT ITS PEAK: Late 22nd century/23rd century/early 24th century. When the conditions on Earth returned to normal, the Terrans in space decided to complete the rewilding effort but instead decided to explore the universe.
INTERSTELLAR MIGRATION: Once the Earth was returned to its pre-Holocene conditions, humanity worked toward creating a city-ship to take space-bound humans out of the Solar System for good. Never forgetting home but likely never to return to it. Around the same time, self-replicating probes were sent out across the galaxy to catalogue various places for further exploration or quarantine. Though some remained in the Solar System.