Notable Arks
Arks are enormous spacecraft, powered by nuclear fusion and propelled by the enigmatic "Slipstream" drives - a name provided by frustrated American scientists, unable at the time to fully grasp the physical basis for their operation. Each can play host to at least ten million people, along with their belongings, in a comfortable environment. Arks possess artificial gravity thanks to the advanced science of the Journeymen.
Each Ark is equipped with an Eidolon, a distributed supercomputer system of alien manufacture. Eidolons are sentient and inhumanly intelligent, though their behavior is restricted by their purpose. They exist only to disseminate scientific and technical data to the human inhabitants of the Ark, and to manage the use of the technology so produced. They lack control over the Ark's life support, propulsion, navigation or communications systems, by design - although many feel (rightly so) that very little would be required for an Eidolon to effectively seize control of an Ark if it wished.
Every nation, and many powerful organizations, approached the act of creating Arks in different ways. Many major American cities, for example, were excavated wholesale from the bedrock of North America, and encased in fused silicates to be launched. The Japanese fleet of Arks are geodesic domes, each cunningly constructed. Many Arks, such as those playing host to tribal cultures, are simply hollowed-out iron asteroids. A few Arks are technically held by private corporations, organizations, or even individuals. These are often much smaller in capacity and sometimes lack their own Eidolon - the Journeymen do not interfere in the pursuit of ideology, but they also did not provide Eidolons for spacecraft that weren't designed to carry large numbers of civilians.
Notable Arks:
"The Big Apple" - a geodesic wrapper around the city of New York and its immediate environs, centered around Manhattan. A volunteer effort to paint the exterior a bright red color is underway; not surprisingly, the city leadership is using this as an opportunity to provide vacc-suit and spacer experience to anyone who seems at all willing to learn.
"Vegas" - another geodesic wrapper, the city of Las Vegas was scooped out of the desert sands and is now the de facto pleasure-center of the North American fleet. It includes a large number of smaller populations and is well-known for cultivating easy-to-grow drug crops.
"Neo-Tokyo" - the flagship of the Japanese fleet. This is one of the most scientifically advanced Arks in the human fleet, having been built by the Japanese with the express purpose of becoming the new center of research and development for humans in space.
"Neo-Kyoto" - if Neo-Tokyo is the soul of Japanese progress, Neo-Kyoto is the soul of its history. Great care has been taken to avoid marring the landscape inside with any sign of foreign elements; on the other hand, there is an unfortunate racist streak among Neo-Kyoto's residents.
"Mockba" - the great city of Moscow, scooped up wholesale by the desperate, single-minded determination of the New Russian elite and the citizens of the city.
"Kiev" - a Ukrainian city steeped in history, tradition, and bloodshed. Its liftoff came about in the tumult of two regional wars, and many of the 3 million inhabitants are factionalized and restless.