The most common habitat in the Belt or among other small planetesimals is the beehive. Tunnels burrowed into rock or ice, often in the wake of mining or exploratory operations, are converted into living spaces by either fusing the existing material or coating the walls with a sealant. Chambers are dug out of the host object and internally sealed in the same manner if additional internal volume is required. Access points on the surface are capped with airlocks, docking modules, or hard seals to prevent depressurization. Beehives are interesting because they are built much like underground bunkers and warrens on the planets, but share the microgravity environment of tin cans and cluster habitats. For people without the training or mods to think three-dimensionally, this can make beehives a veritable labyrinth. Purpose-built beehive habitats use color coding and grid assignments to make navigation easier. Those adapted from mining tunnels or designed for internal security may not have such luxuries.
An asteroid, comet, or Kuiper Belt object has to be large or dense enough to hold itself together to be suitable for a beehive. Rock and dust piles or actively venting comets are just too unstable and usually aren’t worth the energy expenditure to melt into a usable state. As a result, beehives are limited at the lower end to metallic asteroids approximately a quarter of a kilometer on the long axis. Population sizes vary from one or two dozen inhabitants and small communities of a few hundred to the ten million residents of Extropia.
Solar power is an option for beehive stations in the inner system, despite the fact that so many are built into irregularly shaped objects. If there is not enough surface area on the sunward-facing side(s), a power sat with constant collection and transmission capability can beam the energy via laser to receivers on the surface. In the Belt, smaller habitats often rely on Sterling radioisotope thermal generators continuously feeding a capacitor system that balances out peak and off-peak loads. Fusion generators are common in the outer system because of the abundance of hydrogen fuel.
Nuclear reactors (whether ﬁssion or fusion) are the generator of choice for stations with high power requirements, especially in the outer system where solar panels are dramatically less effective, but these habitats must carefully balance safety and security. If the host object is large enough, the generator can be installed behind enough rock or ice to effectively protect residents from radiation hazards and the reactor itself from outside attack. Beehives with an extended long axis will often concentrate the habitable volume on one end and the power systems on the opposite. The smallest beehive communities have even been known to use structural booms to take advantage of the inverse-square law and put the reactor out on the other side of a directional radiation shield, much like spacecraft.