The largest vessels constructed were at the tail of the first wave of colonization. They were behemoths built in the floating dockyards around Titan. Twelve of them were made and each one took thousands of men working for decades to build and fit out. It was said that the wealth of nations were tied into the project.
Each vessel was over five kilometres, long with the largest three being close to nine kilometres. They had a minimum girth of five hundred metres and keel height of twelve hundred metres. They were created for the furthest missions, journeys that would take hundreds of years to complete. They had supplies to last the colonists decades after landing, and were intended to be generational colony supports.
The majority of their journey would be conducted by autonomous systems. They had some of the most complex artificial intelligences created to run the millions of support systems that were required to safely bring the vessels to their distant homes. The intelligences were sufficiently mature that they had comparable emotional matrices to mammalian lifeforms. As such each main system was governed by ten organic crew. They would take turns to wake once every ten years and spend a year in the company of the intelligence. This pattern would repeat for over two centuries, each crew member would age twenty-three years but the artificial intellect would never be alone.
The ten companions were volunteers and chosen form a varied background to best represent the differing balance of humanity. In this way the artificial intellect would have a broad spectrum of understanding to better serve the colonies that would grow and thrive at their final destination. The ten chosen for each vessel underwent a battery of psychological and physical tests to ensure their compatibility and adaptability. They had over a decade of training to bring them to the height of efficiency.
When the ships left the solar system they were heralded as the most significant step into the unknown. They would go further than any humans dared. Humanity would receive centuries of transmissions each one taking longer to return home as the vastness of distance was crossed. The furthest vessel would only be able to transmit a weak radio signal that would take over a hundred years to return to Terra.
Out of the twelve ships that left only nine made it to their destination. Two were lost en route to catastrophic incidents. The twelfth ship went silent within a few years of leaving the solar system, all that is known from its transmissions is that it went drastically off course.