In the near future, mankind has a good chance of expanding its presence beyond the earth. These include the construction of infrastructure in the Low Earth orbit (LEO), on the surface of (and in orbit around) the Moon and on Mars. It presents numerous challenges, as life in space and other celestial bodies carries all sorts of potential risks and health hazards – not least, radiation and prolonged exposure to low gravity.
These issues require innovative solutions; and over the years several have been proposed! A good example is dr. Pekka Janhunen’s concept for a megasatellite settlement in orbit around Ceres, the largest asteroid in the Main Belt. This settlement will provide artificial gravity to its inhabitants, while local resources can create a closed-loop ecosystem that can enter – effectively bringing ‘terraforming’ to a spatial settlement.
Dr. Janhunen – a theoretical physicist based in Helsinki, Finland – is no stranger to advanced concepts. In addition to being a research manager at the Finnish Meteorological Institute, he is a visiting professor at the University of Tatu and a senior technical adviser at Aurora Propulsion Technologies – where he oversees the commercial development of the Electric Solar Wind Sail (E-sail )) concept he proposed in 2006.
The paper describing its concept has recently appeared online and is being submitted to the scientific journal for publication. Elsevier. This is a concept that Dr. Janhunen described to Universe Today as: ‘[T]reform from the user perspective: create an artificial environment, close to Ceres and of Ceres materials, that can expand to the same and larger population that the earth has today. ”
Rotating spatial habitats are a previously required proposal and an alternative to (or with) habitats on other celestial bodies. The first recording was Konstantin Tsiolkovsky’s 1903 book, Beyond the planet earth, where he describes a pin wheel station in space that would rotate to provide artificial gravity.
This is followed by Herman Potoikik’s extensive proposal in The problem of space travel (1929), the Von Braun Wheel (1952) and Gerard K. O’Neill’s revolutionary proposal in The High Frontier: Human Colonies in Space (1976) who asked for a rotating cylinder in space – also known as. the O’Neill cylinder. However, all of these concepts were for stations in a low-Earth orbit (LEO) or at an Earth-Sun lag-range point.
As dr. Janhunen told Universe Today in an email that a megasatellite constellation in a Ceres orbit could use local resources to create Earth-like conditions:
‘It provides Graceful 1 g of gravity, which is essential for human health, especially for children to grow into healthy adults with fully developed muscles and bones. Ceres has nitrogen to make the habitat atmosphere, and it is large enough to produce almost unlimited resources. At the same time, it is also small enough that its gravity is quite low so that the material from the surface is cheap. ‘
According to his study, the megasatellite settlement would consist of rotating habitats attached to passive magnetic bearings on a disk-shaped frame. This will enable simulated gravity within the habitats, facilitate travel within the settlement and ensure that the population density remains low.
Dr. Janhunen estimates that it can hold 500 people per km2 (190 people per mile2), while cities such as Manhattan and Mumbai have a density of about 27,500 and 32,303 people per km2 (or 71,340 and 83,660 people per mile2) respectively. The settlement would initially be provided with a depth of 1.5 m (~ 5 feet), which could be upgraded to 4 m (~ 13 feet).
This will allow green spaces with gardens and trees to produce the oxygen of the settlement and scrub the atmosphere of CO2 (as well as additional radiation protection). Similarly, Ceres is known to have abundant supplies of ammonia salts on its surface (especially around the bright spots in the Occator crater) that can be introduced into the settlement and converted into nitrogen for use as a buffer gas.
Planar and parabolic mirrors around the frame will direct concentrated sunlight to the habitat, providing relief and enabling photosynthesis. Although the creation of such an array would present many technical challenges and would require a great deal of dedication to resources, in many respects it would be easier to colonize the moon or Mars.
As far as that is concerned, it would also be much easier than shaping the moon or Mars. As Dr. Janhunen explained:
‘In some respects it’s easier (no planetary landing needed, no dust storms, no long nights). In any case, the biggest challenge is probably to download the industry from a remote location. “You need a little bit of robotics and AI, but it’s coming out in general now. ‘
But perhaps the most exciting aspect of this proposal is the fact that it makes a spacecraft possible! On earth, such a structure remains impractical (as well as extremely expensive) because the earth’s gravity (9.8 m / s) is2, of 1 g) places serious restrictions on space exploration. In short, a rocket must reach an escape velocity of 11,186 km / s (40,270 km / h; 25,020 mph) to escape from the earth’s gravity.
On Ceres, however, gravity is a fraction of what it is here on earth – 0.28 m / s2 (less than 3%), resulting in an escape velocity of only 510 meters per second (1.8 km / h; 1.14 mph). Combined with its fast turn, a spacecraft is completely feasible and will be inexpensive (compared to transporting other places).
Of course, there is also the benefit that such a settlement would have of exploring (and colonizing) the outer Solar System. With a large population and infrastructure around Ceres, ships destined for Jupiter, Saturn and beyond would have an intermediate point to refuel and stockpile. Potential destinations for colonies may include the Galilean moons, the moons of Saturn or orbiting habitats in both systems.
This would give mankind access to the abundant resources of these systems and usher in an era of post-scarcity. Meanwhile, this Ceres mega-constellation would provide an Earth-like environment for a significant population in the main steroid belt, which could be upgraded to make room for many more people. As Dr. Janhunen indicated:
‘The Ceres megasatellite could probably grow to hundreds of billions of people, so that would be sufficient for at least a few centuries. Discussing the future further is difficult, but in general the spread to various places is life. On the other hand, people like to live in an interconnected world whose parts can [all] access is per trip. ”
The core of Dr. Janhunen’s concept is a marriage of space construction and in-situ resource utilization (ISRU) with some key elements of terraforming being thrown in. The end result of this is a design for a scalable settlement that can enable people to colonize otherwise uninhabitable parts of the solar system. When addressing the future of humanity in space, the challenges and rewards are clear.
To achieve the reward, we must be powerfully creative and willing to commit!
Further reading: arXiv