Evacuation of Kasath

The evacuation of Kasath, known as the Great Flight in Kasatha histories, was one of the largest exoduses in the history of Elyrion, taking place between 1147 and 1230 SSD. Following the Rathyn cataclysm of 1147, it became clear that the stellar conflagrations triggered by the collapse of the ley-lines would destroy all life on the worlds of the inner galactic core, while increasing cost and difficulty of faster-than-light travel over the following decade made an FtL evacuation of the entire population of the core infeasible. While a substantial number of people fled rimwards in faster than light ships, the majority of the core's population relocated to fleets of slower-than-light generation ships constructed by authorities under the Unified Evacuation Plan. Due to the constraints on trajectory imposed by the supernovae, most ships were forced to flee away from colonized space in the East, although a handful of vessels were able to make their way eastward; almost all artifacts of the pre-Silence inner core, as well as all surviving records of pre-contact Kasatha civilization, are found aboard (or in the colonies established from) the known ships launched during the Evacuation of Kasath.

Background

Although largely spared from the bloody conflict of the Ley Wars, the damage dealt to the ley-lines caused substantial disruptions to travel and trade in the inner core in the form of frequent and intense star-storms. As the major powers of the war fractured over the early 1100s, many outside polities hoped that large-scale hostilities would begin to wind down, with major space forces increasingly focused on battling domestic, rather than distant foes. Following the Rathyn cataclysm, however, this strategic calculus was upended. By late 1147 it became clear that the ley-line network would collapse completely within a decade, and most predictions indicated that this collapse would cause a chain of supernovae in the core, the radiation and plasma of which would destroy all life on the surrounding inhabited worlds.

Early Response

With an estimated population of five to seven hundred billion at the time of the cataclysm, it was immediately clear that faster-than-light transport would be unable to relocate the population of the inner core before ley-line collapse made FtL travel impossible, while ongoing turmoil in Aenaz made the prospect of large-scale resettlement in the region politically infesable. News of the impending apocalypse caused widespread panic, and a number of planets collapsed into near-total anarchy over the following years. Although regional authorities centered on Kasath began the development of long-term plans immediately, little central guidance was available in the first years following the crisis.

Almost as soon as the scope of the crisis became clear, the region's passenger star fleet pivoted to emigration; the sudden flood of evacuees caused a number of diplomatic incidents with nearby polities, although the relative wealth of the early emigrants who could afford the suddenly invaluable tickets rimward meant that resistance to their arrival was quieter than had been feared.

However, it was still clear that a shipbuilding effort of nearly unimaginable scale would be needed to ensure the evacuation of a substantial fraction of the population. In anticipation of soaring demand, metals suppliers and manufacturing firms began scaling up production, while the export of key materials was banned all together. Shipyards which had produced civilian vessels initially ramped up the production of their existing FtL transport designs, but this increase was soon sharply limited, as such ships would have less than a decade of use before the collapse of the ley-lines made their starheart drives worthless. The push to totally pivot the region's economy towards ship construction before the designs of the needed vessels had been completed caused chaos, with huge leaps in unemployment and a collapse of the local currency, and by the beginning of 1150 Kasath's economy was in effect run by the central government. Fortunately, by that year the implementation of the unified evacuation plan began in earnest, easing the resulting social unrest.

Unified Evacuation Plan

Under development from mid-1147, the Unified Plan for the Evacuation of the Kasath Stellar Region, known simply as the Unified Evacuation Plan, called for the construction of a vast fleet of generation ships, each capable of carrying between 1 and 100 million inhabitants, and designed to sustain their embarked population for nearly a millennia while searching for suitable worlds on which to rebuild. Construction of the first ships was conducted under a number of smaller-scale programs starting in 1149; by 1151 these disparate efforts were consolidated, and production concentrated on a few highly standardized classes. Following the consolidation of production, emigration from the core was banned, and transports were instead directed to evacuate lightly populated worlds unable to efficiently sustain the needed large-scale shipbuilding.

Although authorities were able to restore order to many of the regions where the chaos of the 1147 cataclysm had toppled governments, many were either deemed too chaotic for a restoration of central authority to be worthwhile or had coalesced around leaders hostile to the government on Kasath. The decision not to devote substantial resources to the evacuation of areas not under the control of the Kasath government remains a subject of debate.

The Unified Evacuation Plan called for each participating planet to divide its ships into between three and ten waves, which would be launched separately and towards different destinations, in order to minimize the risk that local events would destroy an entire planet's population. While the earliest ships were built to evacuate particular settlements, this allocation policy was dropped in 1152 for a planet-wide lottery system based on genetic, social, and educational data, in the hope that resettlement process would address social inequalities and to ensure that each ship had robust base of genetic diversity, cultural knowledge, and practical skills amongst its inhabitants. While a slightly different process was used to populate each ship, the strategy was broadly successful.

The social controls considered necessary to sustain the evacuation ships over their long journeys were first tested in 1149 in the cities selected for evacuation by the first set of ships. As expected, the policies were unpopular; an aggressive education and propaganda campaign only partially dulled opposition. The rocky introduction of the shipboard policies delayed the first embarkations by three months; in 1150, evacuation authorities began a gradual rollout of the controls across all Kasath territories and pushed back the first general embarkations by a year to give time for the population to adjust.

By the time of the Silence in 1159 (the last faster-than light voyage in the Kasath territories took place in 1163 and the last FtL transmission in 1171), much of the first wave of generation ships had been completed and large-scale embarkation of the population was underway. Extensive standardization of ship designs and political protocols, as well as the extensive preparations made over the previous decade, meant that the loss of interplanetary cooperation did not substantially affect the evacuation. The first wave of ships launched on schedule in 1162, followed in 1171 by the second wave. The final ships, whose embarkation represented the near-complete depopulation of Kasath territories, was built largely from material salvaged from the mostly abandoned cities of Kasath, and launched in 1185.

Loss of the Evacuation Fleets

Although evacuation planners had hoped to flee along the eastern galactic arm, the predicted patterns of supernova activity made such a voyage impractically dangerous for slower-than-light ships. Each evacuation fleet targeted a different region of space in the northern galactic arm; although extensive surveys have been conducted by observatories since the Silence, no trace of either the fleets or the colonies they had planned to establish have been found, although the extreme distances involved make such observations extremely difficult. A number of faster-than-light expeditions have been launched in an effort to find the lost Kasath fleets, but none have so far been successful.

Known Ships

Despite the extreme dangers involved, several evacuation ships did end up in the galactic east after mechanical difficulties separated them from their formations.

• The Ahadaliv Ebter arrived in Gen-Greenley 91334-c in 2386. Its inhabitants renamed the system Ahavlae Averen shortly after arrival, and the colony they founded in the system has since grown into the center of a regional trade and mutual-defense body known as the Gamman Ebtinate.
• The wreck of the Ederendan Elso was discovered by observers near Atikon in 2340; an expedition launched to recover it in 2342 discovered that the ship had been destroyed after passing through a cloud of supernova-ejected plasma. Only a fraction of the electronic records aboard could be recovered. Evidence that survivors of the initial catastrophe had managed to sustain themselves for at least three centuries was found.