Asteroid settlements 

and colonies

With inhabited asteroids becoming a popular place for ship construction and servicing, these communities began to grow in permanent population, and rather than forcing people to live inside prefabricated passageways and tunnels in the rock, a new process of generating habitats began to emerge.

            There are two principle types of asteroid settlement, and these two different types are key to which type of habitat is developed. If an asteroid is decided to turned into a Harbour, which exclusively exists to handle the servicing and construction of ships, the settlement will evolve to suit this function, and the type of habitats will develop inside the asteroid, a more detailed article can be found here. If however an asteroid colony ‘retires’ from its ship servicing facilities, or the settlement’s aim is to provide a population base for other space facilities, it will evolve to becoming a true asteroid colony.

            This article will deal with in most part the creation of the type of habitat found on asteroid colonies, the suggested article above better deals with the enclosed type of habitats found in harbours.

The notion of a habitat on any type o settled asteroid is to create an open space, which a biosphere can be raised, these areas provide much relief from artificial environments which dominate space facilities. Harbours are predominantly concerned with the ability to service ships, and there habitats are pockets on the rock which do not interfere with ship servicing operations. On asteroid colonies there is less worry about servicing ships, and the object is to create a fuller and more satisfying environment, for its population.

Key to the creation of habitable asteroid settlements is correction of the ambient gravity, which is always to weak to simulate a proper terrestrial environment. The simplest solution is to rotate an asteroid, and to create a cylindrical inner habitat which is provided with an artificial ‘gravity’ caused by the asteroids rotation, this method, however does not provide a familiar terrestrial environment, instead of the sky above, there is in fact more land. This kind of solution is used on some harbours, but the artificiality of this environment is rarely found on true asteroid colonies.

In abandoning the ‘centrifuge’ technique, asteroid colonies have become dependent on generating artificial gravity to maintain a proper sense of sky and ground. This too has its problems, creating a field to match a planets precisely would involve creating a field that can perturb objects billions of kilometres away, would require a huge amount of energy, not to mention the problem of affecting other objects nearby. This problem, however, is not so important, if one only wants to change the local environment of the inhabitants. Existing gravity field technology used throughout the federation has the power to only generate sizable fields across small distances, gravity generators on board ships create fields only a few metres across, before the effect dwindles to nothing, but this kind of field is perfect for generating a gravity that the crew appreciate, without the ill effects of a Earth sized gravity field extending into space from the ship.

On asteroid colonies the artificial gravity devices are simply augmented, creating an earthlike gravitational field for a few kilometres round the devices, but fading abruptly at its edge, so spacecraft can closely approach asteroids with having to worry about gravitational fields extending away from the asteroid. This feature of gravity that across a few metres can be the strength of Earth’s, and then nothing is a fundamental federation technology, that not only generates artificial gravity, but also provides a propulsion system of spacecraft, and this propulsive aspect is also used by asteroid colonies to move around without generating accelerational forces.

On a simply spherical body, in principle only one powerful gravity-generating device needs to be placed at its core to generate an earthlike field. This would be the case if it were not for the fact that most asteroids are highly irregular, and placing one central device in the asteroid would turn most of the asteroids surface into an unacceptable slope. In reality most asteroids colonized are roughly regular and have at the centres few strong devices for bulk generation, and nearer the surface an array of fine generators that even out the field felt at the ground. This kind of gravity generation removes the dependence on perfectly spherical asteroids fro habitation.

The gravity generating devices are specially created chunks of Driver Coil Material (DCM), which require a suitable energy source to generate their fields. Most small asteroids are reliant on high production fusion power plants, which bathe the DCM in high energy plasma, large settlements may use the rarer antimatter power plants, to produce energy for their gravity generation, though this is rare, and is only ever really suitable if one wanted to provide gravity for very large objects, such as moons.

In more recent times, an alternative to DCM reliant gravity, and its associated energy costs has been developed. Using the same type of spatial curvature generated in the large wormhole gates, a self stable ‘singularity’ can be created, which like wormhole technology generates a smooth and controllable spatial curvature, the differences however is that these ‘singularities’ (though these are not actual true singularities) are meta stable and so only require a very small amount of power to maintain them (small only in the sense that generating similar sized fields by conventional means would require greatly more power input). The problem is initially creating such fields, which requires a vast amount of energy, and the powerful nature of such fields also mean that they can not easily be moved once created using traditional spacecraft engines (the field in fact is manipulated to generate its own propulsion, rather than boxing it up inside a ship). This technology is becoming more wide scale, though one critical problem of remains, and it is spontaneous field collapse, which instantaneously renders the asteroid without gravity, it therefore means that traditional backup systems have to be in place of such an event.

However the technologies behind gravity generation is in principle the same as operating drives on spacecraft, and these technologies have become very reliable and efficient.

Still even with adjusted gravitational field, the surface of most asteroids does not generate beautiful panoramas and vistas, this can be changed by violently rearranging the surface to create mountains and valleys, or any desired features. But some asteroids are quite content with the existing landscape and proceed to develop to the next stage. A completely new form of engineering and landscaping has grown around transforming these asteroid surfaces, often being colloquially described as ‘mountaineering’, the processes involved are often violent and extreme. A common method is to collide smaller bodies into the asteroids surface to create new mountain ranges and basins for lakes etc, though the results although quite impressive are quite dissimilar to natural terrestrial features. Namy other techniques have been developed, from fracturing and faulting the asteroid, to melting and re-volcanising its surface.

However the most important process beyond this macro scale engineering is putting in place a suitable atmosphere and the setting of a biosphere. The new artificial gravitational field generated by the asteroid is still not enough to maintain its own atmosphere, Earth’s atmosphere extends many hundred kilometres from its surface, and recreating this would require correspondingly powerful fields within the asteroid. The solution is surprisingly low tech, though has proved the most effective, it is simply to create an envelope separating space and atmosphere. Generally a multi-layered membrane is used, which can be often several metres thick, but almost completely transparent to the incoming light. The backbone to this membrane is a layer of laminate diamond, which provides the structural strength to the envelope, on either side a layer of aerogel acts to insulate thermally, and also protect against micrometeorites. Amongst this are layers of radiation capture material, which specifically block high-end radiation (x-ray, gamma etc) while being transparent to visible and safer wavelengths.

In addition to the envelope a asteroid may also generate a strong magnetic field which acts to mimic a natural magnetosphere and stops the envelope from receiving significant damage from charged solar flux, which would abrade and degrade the aerogel layer over time.

The envelope suspended over the surface by long masts, which need not be very bulky, as they do not receive a great deal of load, as the internal pressure inflates the envelope, the masts duties are to stop it drifting around or approaching the surface.

The atmospheric gases can be generated from the asteroid if it contains a suitable amount of ices and carbonaceous materials, if not volatile materials may have to be brought in from more suitable icy objects, or from other gas reservoirs (i.e. though wormhole network). Water can be delivered or created in the same way, the greatest problem is generating the organic material which an early biosphere requires. Asteroid regolith is often quite suitable growing medium once excesses have been removed and it is provided with water and nitrates, but carbon content is low, and this will have to be fixed from carbon dioxide from the new atmosphere. The quick way to establishing a biosphere on a new asteroid colony is either to import organic material (quickest but difficult, as quantity and difficulty in manufacture), or to seed a biosphere ‘fast-life’ which consists of simple organisms, predominantly algae and bacteria that can rapidly fix carbon and nitrogen into the proto-soil. Though this method is slower and requires an initial atmosphere which is very high in carbon dioxide and nitrogen compounds (therefore not breathable), it is the preferred method, and is best for covering large areas quickly.

Now that gravity, atmosphere and biosphere are in place, colonization can begin on its surface as it would on a planet. But there are a few unique features of asteroid settlements. Most developing towns or cities will develop subsurface, or more popularly facing the sides of deep canyons, which reduces the encroachment on the surface biosphere, and providing protection from loss of atmosphere.

The population of asteroid settlements will seemingly continue to grow, a very attractive culture has developed in established communities, which achieve a kind of cosmopolitan nature that planet bound cities can not rival, as well as providing a unique environment. Others specifically enjoy creating the little planets, designing in ways that is closed to traditional terraforming, with the benefit that from start to finish may be only a few years.