In the not-so impossibly distant future, it was determined that our sun was prematurely approaching the end of its life as a yellow dwarf, but even the threat of extinction did not unite humanity in purpose. Some welcomed their inevitable demise with religious zeal, some refused to abandon their homes and fought for survival in the scorched cradle system, and some believed in humanity’s future as a spacefaring species; a movement known as the humanity exodus.
While ambitious, the proposal for a space station that would journey to Europa and terraform a new home was not entirely without precedent. Massive space stations already cycled between Earth and a terraformed Mars; though the required technologies existed, they had never been combined at such a grand scale and with such critical purpose.
After several decades of effort, the humanity exodus acquired one of the existing cycler stations and retrofitted it as a generation ship capable of transporting thousands of people across millions of miles of empty space. The station’s low-power engines, originally intended for orbital corrections, required a head start of a few hundred years to outrun the sun’s expansion; so, on one otherwise ordinary day, the navigational systems were booted up, the engines were powered on, and a small subset of humanity began their slow march away from the green paradise of their cradle towards the frozen moon they hoped would be their descendants’ salvation.
Transit Period
As the sun continued to expand and cool, the frozen surface of Europa warmed, exposing volcanic islands. Simultaneously, after three generations of travel, the humanity exodus was limping towards its destination; increasingly frequent coronal mass ejections open_in_new had required taxing evasive maneuvers and damaged key systems, and these delays meant the ark station was on the verge of exhausting its finite resources, requiring rationing measures and birth restrictions.
Colonization Period
Upon arrival to Europa, the deployment of magnetosphere controllers created a depletion region in the Io plasma torus open_in_new and stabilized the moon’s atmosphere, making it possible, if not desirable, for humans to live on the surface. By this time the entire population of the humanity exodus had been born and raised on the station, and the thought of living in the unfamiliar environmental conditions of an inhospitable moon was unappealing at best.
Unfortunately, colonization had to proceed aggressively to establish a supply chain that would prevent the station’s total collapse. Several waves of drafts built resentment among early colonists, who toiled for their service period in bunker-like complexes perched on geologically unstable islands to provide the station with the resources it so critically needed. This resentment was exacerbated by the construction of the low-orbit commerce rail (LOCR), which made exporting large amounts of resources to the station trivial while importing resources to the surface still relied on finicky, small-capacity cargo drops.
As time passed so too did the immediate threat of collapse, and the relentless pressure on the colonies lessened. Leaning on a well-established and now slightly more reciprocal trade network with the station, a few early colonies were able to grow into thriving communities in their own right. The humanity exodus begin looking towards an Earth-like future, where additional islands could be naturalistically terraformed to support the creation of complex natural ecosystems.
Decline Period
The dream of an earth-like future for Europa was waylaid when illness began to tear through the ark station. Close proximity and shared life support systems allowed it to spread rapidly, with new waves emerging despite extensive quarantine measures. It was suspected that the responsible virus was incubating asymptomatically on the moon’s surface, as the symptoms and long-term effects of the illness were milder in those who had previously resided in the colonies. As medical care stretched thin and bodies piled up, travel between and even trade with the surface became heavily restricted, bolstered by a growing public sentiment of reactionary xenophobia on the part of the station dwellers and isolationism on the part of the colonists.
With the workforce decimated and fewer supplies coming in from the surface, the station slowly began to fall into disrepair. Auxiliary systems failed or were shut down, and much of the potential biodiversity of Europa was lost when the cryobanks were finally taken offline.
As the station shut down, the magnetosphere controllers also began to falter, exposing the colonists concentrated on the Jupiter-facing hemisphere to increased radiation. In parallel, cargo hunters—a class of pirate-like mercenaries who tracked and captured the increasingly unreliable cargo drops from the station—had grown in infamy and influence. Three prominent cargo hunters united a faction of colonists to steal critical terraforming resources that would allow them to establish their own colony beyond the reach of the station.
Present Day
Unable to communicate with the station or return to the colonies, much of the history of the humanity exodus morphed into legend as the struggle to survive on the newly-settled islands led to a dramatic technological backslide akin to a dark age. Now, hundreds of years later, the inhabitants of the archipelago are left with only anachronistic remnants of the civilization they descended from.