Living Near Ceres

Some will have heard of Gerard O’Neill’s book, “The High Frontier”. If not, see https://en.wikipedia.org/wiki/The_High_Frontier:_Human_Colonies_in_Space. The idea was to throw material up from the surface of the Moon to make giant cylinders that would get artificial gravity from rotation, and people could live their lives in the interior with energy being obtained in part by solar energy. The concept was partly employed in the TV series “Babylon 5”, but the original concept was to have open farmland as well. Looks like science fiction, you say, and in fairness I have included such a proposition in a science fiction novel I am currently writing, However, I have also read a scientific paper on this topic (arXiv:2011.07487v3) which appears to have been posted on the 14th January, 2021. The concept is to put such a space settlement using material obtained from the asteroid Ceres, and orbiting near Ceres.

The proposal is ambitious, if nothing else. The idea is to build a number of habitats, and to ensure such habitats are not too big but they stay together they are tethered to a megasatellite, which in turn will grow and new settlements are built. The habitats spin in such a way to attain a “gravity” of 1 g, and are attached to their tethers by magnetic bearings that have no physical contact between faces, and hence never wear. A system of travel between habitats proceeds along the tethers. Rockets would be unsustainable because the molecules they throw out to space would be lost forever.

The habitats would have a radius of 1 km, a length of 10 km, and have a population of 56,700, with 2,000 square meters per person, just under 45% of which would be urban. Slightly more scary would be the fact it has to rotate every 1.06 minutes. The total mass per person would be just under 10,000 t, requiring an energy to produce it of 1 MJ/kg, or about 10 GJ.

The design aims to produce an environment for the settlers that has Earth-like radiation shielding, gravity, and atmosphere. It will have day/night on a 24 hr cycle with 130 W/m^2 insolation, similar to southern Germany, and a population density of 500/km^2, similar to the Netherlands. There would be fields, parks, and forests, no adverse weather, no natural disasters and ultimately it could have a greater living area than Earth. It will be long-term sustainable. To achieve that, animals, birds and insects will be present, i.e.  a proper ecosystem. Ultimately it could provide more living area than Earth. As can be seen, that is ambitious. The radiation shielding involves 7600 kg/m^2, of which 20% is water and the rest silicate regolith. The rural spaces have a 1.5 m depth of soil, which is illuminated by the sunlight. The sunlight is collected and delivered from mirrors into light guides. Ceres is 2.77 times as far as Earth from the sun, which means the sunlight is only about 13% as strong as at Earth, so over eight times the mirror collecting are is required for every unit area to be illuminated to get equivalent energy. 

The reason cited for proposing this to be at Ceres is that Ceres has nitrogen. Actually, there are other carbonaceous asteroids, and one that is at least 100 km in size could be suitable. Because Ceres’ gravity is 0.029 times that of Earth, a space elevator could be feasible to bring material cheaply from the dwarf planet, while a settlement 100,000 km from the surface would be expected to have a stable orbit.

In principle, there could be any number of these habitats, all linked together. You could have more people living there than on Earth. Of course there are some issues with the calculation. The tethering of habitats, and of giving the habitats sufficient strength requires about 5% of the total mass in the form of steel. Where does the iron come from? The asteroids have plenty of iron, but the form is important. How will it be refined? If it is on the form of olivine or pyroxene, then with difficulty. Vesta apparently has an iron core, but Vesta is not close, and most of the time, because it has a different orbital period, it is very far away.But the real question is, would you want to live in such a place? How much would you pay for the privilege? The cost of all this was not estimated, but it would be enormous so most people could not afford it. In my opinion, cost alone is sufficient that this idea will not see the light of day.

6 thoughts on “Living Near Ceres

  1. Dreams of space colonization collide with a simple fact: our compact energy source is hydrocarbons. At best, methane, CH4. So-called “Green hydrogen” would not be useful in space, because it would have to come from H2O, which is more precious. Energetically, we are still Neanderthals.

    Reciprocally, though, if we had compact thermonuclear fusion, we could start colonizing right away. SpaceX style rockets could land factories on Mars and start to build cities and make oxygen. Another nuclear, tech, fission, could reduce travel times in the solar system, and augment the payloads carried, by using nuclear fusion heavy duty ferries.
    So it all boils down to energy.

    Although we do have photovoltaics, there are not very efficient (20%-45%), and they need large surfaces. So our main energy source is still fully Neanderthalian!
    We need ENERGY progress…

    Something which strikes me about proposed space colonies is the waste of space in the proposed concepts. Of course, in the beginnings, we are not going to try to recreate Iowa in space. Agriculture will probably be hydroponic, concentrated… Starting with Moon colonies: the Moon has a lot of solar energy, especially on these tall crater rims by the south pole on which the sun does not set… And the Moon has water, much more than we thought it had… There again, caught in the regolith, so it has to be energetically extracted…
    It will all boil down, but we need energy.

    Fortunately, NASA is seeing the light again. Perseverance, which just landed on Mars, is NUCLEAR powered. Solar probes failed, because they were solar (dust covered the panels). NASA is also realizing that nuclear fission will enable us to get to Mars in 6 weeks, not 8 months.

    Of course the anti-science,anti-technology, anti-colonization, anti-reason critters are seriously in the way… Although their ancestors were colonialists… and not necessarily nice colonialists or slave masters… At least Kamala Harris is discrete on that one (Her ancestor Mr. Harris was a wealthy English lawyer cum slave owner)… Not like Michelle Obama… Let me explain: Obama cut down hydrogen research, to the bone, Trump re-established it. Although Biden presents himself as science president, demonstrated by wearing two masks while vaccinated, investors are not clear about whether he is not saying one thing, to cover the fact that he is doing the opposite, as Obama did.

    And the first real hard data indications on Biden’s science drift are not reassuring: whereas under Trump the overall US Congress mandated science budget augmented 17% a year, average, the first Biden budget has only an augmentation of 1% of the science budget, a small fraction of real inflation.

    We would probably already have a functional thermonuclear fusion reactor, if the spending in controlled thermonuclear fusion was open full throttle (ITER was pushed back ten years from lack of funding…).

    Instead the so-called “Democratic” Congress wants to spend 120 million dollars, in the latest “COVID” stimulus budget, building a tunnel in Silicon Valley so that the plutocrats will not hear the train anymore! The existing train line passes next to Atherton, the wealthiest city in the USA, made of palaces next to downtown Palo Alto (I have two train lines below my windows, I survive… But my wealthy (ex)friends in SV in their leafy ten million dollars homes can’t stand the possible rumble… although they don’t mind the roar of their private jets… to go skiing…)

    Why are the anti-colonization critters so loud? Because, as with animal rights, it diverts from debating the ongoing most severe real problems, such as the molding and selling of our souls by the tech monopolies, for profit…

    • Too many points there, Patrice. I agree on the energy issue, and we cannot colonize space using chemical rockets – too much fuel is carried – the great bulk of the starting weight is fuel and tank. I regard trying to get humans to Mars, say, using chemical rockets is similar to trying to cross the Atlantic in a coracle. If you built a big and stable enough one you could do it (enthusiasts have rowed across) but it is a stupid way to go. Much more effort should be put into getting thermonuclear fusion to go. You need huge electricity production so you can accelerate ions up to nearly light speed, which gives far more momentum impulse for the least weight of mass.

      You need a lot of space on a space station because you want the people in it to have something approaching 1 g directed to a “floor”, but you don’t want to spin that fast that you generate too many weird Coriolis effects. Whatever happens, it won’t happen in my lifetime.

      • People survive in the ISS for a year. It will be telling how long they can survive on the Moon if a station is built there. 1/3g there… One may be getting by with a mix of reduced gravity and heavy load carrying exercize…
        Turns out serious runners spend most of their time as couch potatoes (I can testify to this)

  2. I think the Moon is roughly 1/5 g so it is worse than what you think. As you say, a heavy load will compensate for some muscles, but I am not sure about others. If we live long enough, I guess we shall see. You can always spend sessions in centrifuges, including eating and sleeping.

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