The proposal is to build an extraterrestrial settlement in Ceres orbit, using the resources of Ceres, lifting them up by a space elevator or rockets. The settlement consists of several spinning O'Neillian cylinders attached to a common megasatellite frame. The geometry is growable and could scale to almost unlimited size, eventually providing much more living area than Earth. The population density is by default a moderate 500 persons/km2, which is similar to the Netherlands. In the paper, the settlement is described to use natural sunlight collected with parabolic reflectors and be divided into rural and urban layers.
The benefits are that one has healthy earthlike 1 g artificial gravity inside the settlements, but also the possibility to travel effortlessly and sustainably between the cylinders so that the orbital megasatellite world becomes and interconnected set of paradise islands. The combination of these features sets the Ceres megasatellite concept apart from other extraterrestrial settlement ideas like Mars settlements or traditional O'Neill cylinder islands.
The reason we select Ceres is because Ceres has nitrogen for the settlement atmospheres. A space elevator for Ceres is feasible with ordinary engineering materials. Lifting the materials by reusable rockets would also be possible, but it would require setting up propellant production on the surface and would be less enery-efficient solution than the elevator.
Ceres material is mined sequentially, all is used and no waste is left behind. This is possible because the radiation shields dominate the mass and their composition is flexible. The radiation shields reside in microgravity so they need almost no mechanical strength. The spinning habitats are inside the radiation shield cylinders.
An interim, less growable version of the megasatellite could be built in Mars orbit using resources of Deimos. If Deimos does not have enough nitrogen for the atmospheres, it can be imported from Mars more cheaply than from Earth.
The paper: https://arxiv.org/abs/2011.07487 and the associated slides.
Light cycle in the 3 timezones by sloping ceilings:
1.5 hour public seminar at URSA (in Finnish), 13 April 2021.
1 h interview by Orbital Assembly Corporation, June 1 2022.