Ever since the dawn of time people have turned their eyes to the sky and dreamed of flying. The mysteries of the clouds and the desire to see the world from above always called out to people.
With the emergence of mechanical, non-magical flight these dreams came closer to, and eventually became, reality. As flight became common the need for nations to control and manage their airspace grew. At first, this need was only military but eventually the need to observe weather patterns and air traffic became strong enough to rival military interests.
As the technology for airships and dirigibles evolved the amount of time a vehicle could spend in the air increased. Soon the only thing keeping airships from staying in the air indefinitely was the occasional need to refuel. The ability for one airship to deliver fuel to another made this a relatively easy problem to solve.
With this the first permanent air stations appeared in the sky. They were essentially just large airships stationed where they could observe strategic locations from a safe and convenient distance. Rather than having them return to base to refuel, smaller airships delivered fuel for the engines and food for the crew.
Over time the air stations grew; the areas they were able to observe became larger and they were able to reach even higher altitudes. These days a typical air station hosts a crew of several hundred and the very largest ones staffing over two thousand crew members. The typical station remains stationary at roughly 15,000 meters altitude and observes an area equivalent to a small country.
Most air traffic flies at significantly lower altitudes, but above 15,000 meters there is very little wind and stations usually have no issues remaining in one place.
At this altitude the outside temperature is very low and the crew will only venture outside in case of emergency hull maintenance or other similar emergencies. Some stations still do not have internal hangars for receiving deliveries and on those ones crew will have to venture out into the cold in order to oversee landing and take-off.
A fully stocked air station can remain in the air for up to six months without restocking fuel. Water can be harvested from clouds by smaller air ships carried by the station and should not be a problem. Most stations have facilities for growing their own vegetables and the ability to convert most of the bodily waste produced by the crew into fertilizer. However, the vegetables alone can’t sustain a crew of hundreds for long. Conserved food is stocked in abundance in case a delivery is missed.
The vast majority of air stations are maintained by the respective nations they belong to, but a few independent ones exist. These are generally owned and maintained by large corporations as part of their business; either as vacation or holiday retreats, or as research stations making use of the special conditions of the very high altitude.
Finally, there are several offshore stations located over unclaimed waters above the sea. These stations function as independent airborne city-states with their own local government, usually in the form of just one individual or a small council. Many of these independent stations serve as centers of operations for various criminal organizations and their exact locations are kept secret.
Less common than the high altitude stations are the low altitude ones. These generally only exist in areas with mostly calm weather, where storms are uncommon. They’re particularly common in the southern marshlands where building on the ground can be treacherous at best.
Low altitude stations are often situated no more than a few hundred meters in the air and may even be anchored to the ground depending on need. While individual low altitude stations are usually quite small they often group together, creating large floating cities in areas where building on the ground is not an option.
The smaller low altitude stations are generally mobile, and those who don’t have their own method of propulsion can easily by towed around by those who do. This means that when the need arises a station can leave the floating city it was a part of and move on to another location. In this way the floating cities come and go, frustrating cartographers the world over.