space L4 settlement

My next idea is a half million population settlement at the L4 Lagrange point. Situated there the large cylinder will be gravitationally held in place by the Sun and the Earth so very little position correction will be required. It will be made up of three connected 2500m radius cylinders. The middle one is the settlement, 10km long, and on either side is a matching radius but shorter cylinder, on one side for food production, and the other, for industry. The whole complex will be radiation protected by a powered superconductive solenoid that is in the shade so as to be kept cold. What follows are the ideas I have about it.

As with other past posts, this would begin with sending an automated system to that L4 point that processes ERO NEA asteroids to get fuel and to build regolith bricks and to produce metal ingots that can then be fabricated into metal sheets and beams for construction. In fact, at L4 there may already be asteroids or comets being held in place due to the nature of L4.

Shipped from Earth would be the YBCO Superconductor as this is not something that is easily produced and that could be produced in situ at L4.

To handle radiation, have on the shady side of the cylinder, the length of the cylinder the YBCO solenoid fixed to an insulating backing to keep the temperature at or below 93K. It requires only 100kW for 10 seconds to charge it up. This initial charge would be done before the cylinder has begun to spin, so that it would be easy to attach a cable from the cylinder to the solenoid to charge it. It would have affixed to it a few thrusters throughout so as it can be repositioned periodically since it will not be attached to the cylinder once the cylinder is spinning. Attachable is a separate autonomous machine that has thrusters, significant batteries, capacitors and solar panels. The charger can detach and move into sunshine to charge up the batteries. When it is needed to recharge the solenoid it can return and attach to it and charge up the capacitor and the capacitor can feed the solenoid.

Paris has a population density of 20,000/km2. If the settlement cylinder is 2500m radius and 10km length, the surface area is 2*pi*r*l = 157 km2. If all 157 km2 was at Paris density it would be 3.1 million people. With half a million population in this cylinder the population density will be 3183 people per square km.

The construction will consist of an outer circular cylinder and then 4m within that a regular dodecagon; so the outer cylinder would actually be 2504m to allow for a 2500m circumradius dodecagon which provides 12 equal sides of 1294m and a perimeter of 15530m.

With 15530m perimeter and 10km length, the interior surface area would be 155.3 km2. The inner dodecagon will be supported by support beams that connect the outer cylinder to the inner dodecagon perhaps every 10m at every vertice and at the midpoint of every dodecagon side.

Using thrusters positioned at the four cardinal points on the exterior of the cylinder positioned perhaps every two km along the length of the cylinders, the thrusters will initiate and adjust as needed the position and rotation of the cylinder to bring it up to 0.6 RPM which will generate 1.00g at the 2500m circumradius dodecagon interior and ever so slightly more at the 2504m cylinder radius.

As with past posts where I’ve described the construction, the exterior will be coated with 2m of asteroid regolith bricks to protect further about radiation or any errant space debris that could come into contact with the exterior. Resting on that exterior of asteroid regolith bricks would be solar panels across all of the round surface of the 2500m cylinder. Using ChatGPT-4o’s help, I found that a 2500m radius 20km length cylinder covered in 18% efficient solar panels and spinning at 0.6rpm would generate 77GW. To put that into perspective, the province of Quebec with cold winters and over 8 million residents, generates around 42GW. We will be flush with electricity.

The interior of the cylinder will be coated with an impermeable and smoothed out layer to protect from space egress and to provide a smooth surface to the infrastructural needs of this sub level.

The sub level would only be accessible to specific people, not to the general population. Principally it is for infrastructure like water and sewage management, electricity and internet supply and other uses. For example, a handful of electric medic golf carts could be imported from Earth so as to bring anyone from anywhere in the settlement to the hospital quickly. Also, the temperature control system could be attached to the ceiling with occasional vent holes up into the settlement.

Now we get to the interior of the settlement cylinder where we have essentially a 15.5x10km rectangle with a 150 degree incline change every 1294m in the 15.5km direction.

The first thing I would suggest is that we divide it into quadrants, NW, NE, SW and SE and that at the center of this configuration we create central city things like a sports stadium, a concert hall, the hospital and university. I wrote a previous post about having a space university that gives details about all of the programs that it could offer. In addition to those programs it could give one year certifications for becoming full time farm worker or working on the industrial side, or on the infrastructure team.

The next thing is that there will be no cars; instead, at every second vertice along the dodecagon perimeter, there will be bidirectional moving walkways that lead to the center. Being at every second vertice means that at maximum a person would have to walk 1294m either to the moving walkway to the left or to the right, and most people would be walking less. There will additionally be paths that are perpendicular to the moving walkways that do a full perimeter circuit and that lead to the moving walkways. I would have km markings installed on the floor of these perimiter following walkways so that if someone was using the path for running exercise, they could track their kms.

Each of the four quadrants will be further divided into quadrants (called sub quads) and at the center will be a high school, a gymnasium and pool and other facilities that could be used by all of that quadrant. The high school would also have a dining hall so that the students (and staff and teachers) there can have both breakfast and lunch. There would also be a medical facility with GPs, physiotherapists, psychotherapists, dentists, gynecologists and others.

Each of the four sub quads will have a daycare/primary school and perhaps smaller shops like a hairdresser, barber shop, pedi/mani place. The daycare and the school will be separated by a kids dining hall. Daycare kids would enter on one side and primary school aged kids would enter the other side and all of these kids would have breakfast and lunch provided. Each sub-quad could also have a poly-denominational church/mosque/synagogue. Maybe one sub-quad for each quadrant will have a tennis complex, while another sub-quad in each quadrant will have a soccer field. In this way quadrants could have competitions with each other.

In terms of the living quarters, the first level of all of the apartment complexes will be for accessible purposes, the second and third level will only be accessible by stairs. There will be no elevators at this settlement except perhaps at the university and/or hospital at the center. The apartments will have no kitchen as all meals will be eaten in communal dining halls. There is significant food waste on Earth, here on this settlement we need to do everything we can do avoid food waste. By having dining halls for groups of 120-150 residents we can make certain that we serve to people as closely as possible exactly how much they will eat, and leftovers management can be managed better. Also, by centralizing meals this way we can ensure everyone gets all of the nutrition that they need, including vitamin D which without sunlight would be harder to obtain. Given this plan of having a dining hall for 120-150, there will be apartment complexes that will hold that many people with an interior courtyard that is a communal place for dining and hanging out and for kids to play.

The apartments will have a small living room, one, two or three bedrooms, a balcony and for the bathroom I am thinking of it being a little more complicated. I would want the urine to be processed in such a way that it can be cleaned and re-entered into our potable water system, something that the ISS is already doing. I want the defecation to be macerated, transported to be heat-composted and then aged and accumulated and then used in the farm that I’ll get to later. Also, since any form of paper will be rare, all of the toilets will have the bidet function built in, basically Japanese toilets. So it could be that each apartment will have two toilets, one clearly marked for urine and the other clearly marked for defecation; though unlike the ISS, if someone has to pee while pooing, we would let that go down the defecation channel.

Now would be a good time to indicate the social structure of this city; it will be a social democracy where once the settlement is mostly populated, it is the citizens that run it. There won’t be money or salaries and each member of the city will be expected to contribute in any number of ways. This could include janitorial, working in the kitchen, having a more official job like teacher, nurse or doctor, being a full time farm worker, being a full time industrial worker and so on. All food and lodging are provided as well as internet access, heating and hot water, attendance at sporting events and music concerts and so on. Any farm produce that is in excess of what the settlement needs can be sold to anyone outside the settlement with that money coming to the settlement and that the highest level committee will decide how it is to be spent. Similarly if there is any industrial revenue, that revenue will also be spent by the settlement committee.

The lowest level of the social structure is a small committee that represents the apartment block of 120-150 people. This small committee will manage things like who is working in the kitchen of the dining hall, who is cleaning the hallways or responsible for repairs and so on. A chairman of the apartment block would be chosen and this person would meet monthly in the sub-quad committee.

The sub-quad committee would meet monthly to discuss things about the sub-quad, like who are the daycare workers, who are working in the kids dining hall, who are the teachers, what are the teacher’s needs and anything else pertaining to that eighth of the entire settlement. A chairman would be chosen to represent the sub-quad at the Quadrant level.

At the quadrant level the leader from each of the subquads would meet with a fifth person who is chosen or selected from anywhere within the Quadrant to act as chairperson with a tie breaking vote privilege. This committee would manage things that are quadrant related, like about the high school, the facilities and of course to hear about anything at the sub-quad or apartment block level.

In all cases of these committees the members would be on the committee for three years and it would be staggered. Of course the very first committee would be all members starting together, but one third could have a 1 year mandate, one third a 2 year mandate and one third a 3 year mandate. Committee members can stay on if they choose to for a second 3 year term, but then must leave for at least one year before applying for or being elected to the committee again.

Finally at the settlement level there would be each of the four quad chair people, as well as a few others, like the Farm manager, the Infrastructure manager, the Industry manager and perhaps one or two others. This committee would make decisions that affect the whole settlement, things like the schedule for sunrise/sunset, the temperature of the settlement, immigration decisions, settlement security and others. I would be curious to know if this committee would allow for sex workers to setup shop which would be a little odd in a no pay social democracy.

In each of the four quadrants and connected to each other so that it forms one continuous and sinuous path, is a park that may be narrow in places and wider in others that will have plants, trees, benches, in some places games like ping pong or a few mini-golf holes and all with a central path the leads through it. It should be possible to make this path have a total length of exactly half of a marathon so that once or twice a year we can have a marathon (two laps) and half marathon race open to all citizens.

With most buildings being residential and being three stories high, there could be rooftop terraces from which it would be possible to see far to either side of the cylinder to see the settlement curve up into the ceiling, and also to see towards the center where some taller building are for the hospital, university and sports stadium.

The next construction part is a circular light panel that spans the length of the cylinder with a zero g catwalk within it to allow access if ever needed. The light panel would be bright enough to simulate sunlight, or bright enough to simulate a cloudy day. At sunset it would dim and change colours gradually for the span of an hour until it is all dark except for a few random lights that stay on brightly, acting as stars in the sky. In the morning the lights would slowly come on through various hues over the span of an hour and will end up back in daylight.

The first people to arrive will be the construction workers who are helping to build the settlement; they will have brought with them MREs. The second group of people to arrive are for the farm so that they can get it started, there will be more about the farm later. The third group of people to arrive will be more construction workers to accelerate the building of the downtown buildings (university, hospital, sports stadium, concert hall). With those under construction the first residential apartment complexes will start to go up, first in one quadrant, and then the first one in the second quadrant, and then the first one in the third quadrant, and then the first one in the fourth quadrant. Further residential buildings, moving walkways and the linear continuous sinuous park would get created as needed in all quadrants.

Once that has come along, the settlement will be ready to receive new settlers at a higher rate, to populate the hospital, the university, to help further with the construction and the farming.

In terms of immigration, at the beginning it will be very specifically for construction workers, farmers with aquaponic and hydroponic experience, the nurses, doctors and teachers. Of course for all of these people, they will need to agree to the social democracy way of living without money or income but getting the benefits of society. Once a certain threshold is met, then the requirements for immigration will become more lax and a constant flow of incoming people will get us to the half million citizens.

In addition to all of the different roles already described, I can imagine a media company being created that has people that do radio broadcasts, television broadcasts, sports broadcasts, make TV shows, even make movies. So all of the production staff, actors and actresses, extras, directors, producers and so on would be welcome.

With respect to fire safety, candles, matches, flints, lighters, cigarettes or anything that can be smoked will all be prohibited and searched for before anyone headed for the settlement leaves Earth. As water is not so easy to come by we won't have sprinklers in the buildings, but we will obtain from Earth fire extinguishers, especially for all of the kitchens, but in the residences as well.

Some people may come to the settlement to retire and who would eventually die. Each sub-quad’s church/mosque/synagogue could host the funeral and perform the burial right in that church building. The body would be lowered into the sub-level where it would be an infrastructure person’s job to take that body away. Incineration may be too energy intensive, but launching the body towards the Sun may be an option. A plaque can be created and then affixed in an obvious place within the church building to denote that X person was buried here on Y date. Perhaps at an edge of the industrial cylinder (discussed below) a sling shot exit can be created for the jettisoning of any material, that has enough force as a sling shot to jettison whatever (including the dead person's body) towards the Sun, or at least out of the L4 gravity well. It is likely that sling shot exit would push the entire settlement off course but as a mass comparison it wouldn't be much and over night the exterior thrusters can be fired to move it back on course. Yes, any time the whole settlement needs a positioning adjustment, this would happen overnight when most people are sleeping, so that if there is any jarring motion, however slight, it will disturb as few people as possible.

On the north side of the settlement cylinder will be affixed the farm cylinder that has the same outer cylinder dimension and could be 5km long, or perhaps more, depending on a much more detailed analysis of how much space is needed to grow the food needed by the settlement citizens.

There will be hundreds of separate aquaponic setups; each one with its own fish tank and hydroponic growing system. As an example, there could be twenty four setups for one type of tomato that are growing in such a way that twice a month there are some ready to harvest. Repeat this pattern on four levels covering the entire cylinder for all of the different things that get grown.

The most popular and easy to grow aquaponically are tomatoes, lettuce, watercress, peppers, cucumber, cauliflower, cabbage and strawberries. More challenging, but further possible things to grow aquaponically include Sweet corn, Beets, Dwarf citrus tree, Onions, Radishes, Orchids, Violas, Microgreens, Asparagus, Wheatgrass, Pak, Choi, Swiss Chard, Arugula, Chives, Carrots and Onion. Finally, there are some nutrient hungry plants that can be tried: Beans, Squash, Broccoli, Peas, Flowers, Bananas, Citrus fruits. It would be great if we could find a way to grow durum wheat (or any kind) to see about making bread and pasta. The fish that can be grown include tilapia, carp, trout, perch and catfish. Some of these fish may have more specific water temperature requirements, so those would be paired with crops that can handle that temperature.

One portion of the farm will be set aside to have a 3m depth mix of 2 parts asteroid regolith powder and 1 part Earth soil in order to grow an orchard of apples and pears. The humanure that has been heat-composted and aged and so is safe, would be buried in with the orchard to improve the soil there. With half a million residents the amount of humanure would become excessive, so we would prepare it for export as perhaps other space habitats could use it. It is possible that we could store large packs of humanure outside of the settlement as the amount of space out there is practically infinite.

Another portion will be to have chickens so as to produce eggs.

Another part of the farm will work on self sourcing, for example, how to get the fish eggs to reseed the fish in the aquaponic systems – or in the case of tilapia, they seem to replenish themselves. How to get seeds for the plants growing in the aquaponic systems. It may be economical to place a large seed order from Earth since seeds are small and ship easily. How to create the hydroponic growing medium and how to make fish food. How to get chicks to grow into chickens to replace the ones that die so as to keep up egg production.

Finally, yet another part of the farm will be a food processing plant to process the harvested food into end or interim products to be put into reusable shipping boxes that will go out to the various apartment complexes. Having a passage open between the farm cylinder and the sub-level of the settlement cylinder, a worker using a cargo bike would deliver the reusable box of food to specific apartment complexes who had placed an order for such products. The dining hall’s kitchen will have a way to retrieve the delivered box and to return to the delivery worker the previously used and now empty reusable box. These plastic boxes could presumably be 3D printed from the industrial side of this settlement.

As the food is important for everyone, every citizen will be expected to do a few hours every week at the farm. There would be a farm manager and an algorithm such that when anyone who isn’t a full time farm worker shows up, on their mobile device will appear two or three tasks that in that moment need to happen, and so the person will pick one, it will get removed from the list so on one else gets it, and then they go and do that task. Once the task is done they would flag it as done and then ask to get prompted for another set of tasks to choose from. Additionally, primary and secondary school classes can have once a month a session, scheduled to be one class of students at a time, to go to the farm and learn about doing (and doing) the various tasks that need to take place. A full time farm employee would be tasked with going to the primary school whose class is going, to help, with the teacher, to guide the young students to the farm. For secondary students the farm worker would simply greet them at the farm.

As every citizen will be required to do some and they have to use the app from which they select which task they will do; it will become obvious to the farm manager when she looks at the delinquent report, that the people in that report aren’t doing enough. I do not know what ought to be done about these people, but the settlement committee can make a decision about it. Perhaps it can be three warnings and if still no pickup on the farm labour, deportation.

On the far side of the farm cylinder, the side that is at the end and has empty space on the other side of it, a handful of observatories will be built to allow for citizens to come here for a visit and to look out into space.

So on one side of the settlement cylinder will be the farm cylinder; on the opposite side of the settlement cylinder will be the industry cylinder.

The industry cylinder will have in it various manufacturing and other industries to supply to the settlement, and possibly to other space habitats, any of the things that might be needed. In my head I started from awakening; we may need bed sheets, clothing, pillow cases, towels. Perhaps none of these could be made without Earth’s help, but maybe we can find a way to recycle what gets brought to this settlement. Then if I want to brush my teeth I’ll need a tooth brush and tooth paste; for the former we can get everyone a handle and then import from Earth just the head part in large bulk. For the latter maybe there is a way to make it and put what is made back into an existing emptied tube originally from Earth.

Then there is soap, shampoo, conditioner, skin moisturizer. Apart from the containers these would go in, I suspect that we could find a way to produce these, and refill containers that were brought from Earth when the settlers first arrived. For more specialty products we could place an order from Earth.

Maybe there is a way to produce Impossible Meat or Beyond Beef that can then be added to the food that we farm to provide to the apartment complexes.

I am confident that other people would find many different ideas to make use of the industrial cylinder to make use even of the low gravity if they work closer to the center of the cylinder.

On the far side of the industry cylinder (like at the end of the farm side), the side that is at the end and has empty space on the other side of it, a handful of observatories will be built to allow for citizens to come here for a visit and to look out into space.

The original asteroid processing plant could continue to operate outside of the industrial end, to reach further and further asteroids to bring them in for water, hydrogen, fuel, metals, carbon and so on. If we encounter any rare Earth metals, we could sell them back to Earth through the next ship that goes back to Earth.

In terms of getting to and from Earth, after the initial loads that get sent and after the first 1000 or so settlers have arrived, we as the settlement could build a space ferry that goes from our settlement to a gateway station in Earth orbit. Given our fuel production capacity, we could even sell fuel back to Earth ships on our return there.

Upon further research I discovered that using rocket fuel to exit Earth’s LEO and then using an Ion drive to travel to L4 could take as much as 2.5 years given today’s technology. I would hope that by the time that this station is starting to be built, that we can cut this time in half. Given this we as a settlement would create two ferries, so that every seven months or so one is leaving and one is arriving. Or maybe we create four ferries so that we have a ferry about every three months.

I am not certain if there are any more space chapters that I can add to what I have already added in the last ten days. Maybe I will think of something.