L4 Settlement Part 11

Having decreased the travel time to get from Sun-Earth L4 to an Earth mid LEO gateway station to be just under a week using first and last quarter of distance to accel/decel at 2m/s2, I though to apply the same thing to retrieve ammonia from the Kuiper belt for the purposes of getting the Nitrogen for the settlement, farm and industry cylinder atmospheres.

I had ChatGPT-4o assist me with this. I start with a dry weight 20t space vehicle that has the capacity to carry 200t of ammonia asteroids, that has thrusters on both sides so that it doesn't have to turn around to decelerate, it leaves our L4 settlement and for one quarter the distance accelerates at 2m/s2 and then decelerates for the last quarter at the same rate to end up at the 1/3 mark of the Kuiper belt. Then I have it spend two months there accumulating 200t of ammonia laden asteroids. Then I have it fly back under the same conditions, but now under load.

The total trip, including those 2 months in the belt, adds to 100 days and would take 1884t of Hydrolox fuel, needing most of it on the return trip since there are 200t of mass to push. In my previous post about going to the Kuiper belt it was close to a 12 year round trip, so bringing it down to 100 days is a huge improvement and makes it easier to obtain the required Nitrogen.

I found out recently that Titan, one of Saturn's moons, has an atmosphere that is 95% Nitrogen gas with most of the rest methane. I was going to try to figure out what the gravity well would be to land on Titan, simply pressure air from Titan's atmosphere into tanks and then take off again back to L4, but then I learned that this moon is almost as far from L4 as the Kuiper belt is, so rather than fight the gravity of Titan, we would just go that little extra distance.

I realized that if the farm is 5km long and the food processing plant is only on one side of the dodecagon, the farmer at the 180 degree opposite side and furthest away at 5km will have a very long way to push bins that contain harvested food to get it to the food processing building. Given this I have decided to keep the roller tracks that are between farms that lead to the food processing building, but I will also have conveyor belts replacing the roller tracks in many places. The conveyor belts will not run every minute, but rather will activate when a sensor somewhat upstream notices the presence of a bin, and then will turn on for a set period of time that surpasses the length of time a bin would be on that belt.

For the food processing building, I can imagine a long three alley system. The alley that is closest to the farms side of the building (alley 1) will have harvested goods come on a conveyor belt where sorters empty the bin. For any food that is ready to go immediately to an apartment complex, that food goes on a wide table that separates alley 1 (from the farm) to alley 2 (goes to the apartment complexes). The way food is put on that table is to ensure that it follows FIFO order. So an alley 2 person, a fulfiller would take the food and put what is allocated into the outgoing bin.

The sorter would take, for example, potatoes, carrots, corn and fish and put those in a different queue so that cleaners can take them to clean them. This cleaning station would be outside of the sorting station. Once clean, these food items would go back into bins to go on alley 3 (from the cleaners) so that sorters on alley 3 can put these food items on the wide table that separates alley 3 from the fulfilment alley 2. So fulfillers on both sides of alley 2 will fulfill the outgoing bin from alleys 1 and 3 and then just push it along until it has been fulfilled to 100% to then be sent out into the settlement cylinder through the sub-level ceiling automatic distribution network.

The sorters in alley 1 would take the empty harvest bins and put them aside to stack and accumulate. At night, the conveyor system that brings harvest bins to the food processing building will run in reverse so as to return empty harvest bins back to the farms. So the last task that the last sorter does at the end of the day is to place the empty bins in smaller stacks back on the belt so they can be reversed out back to the farms. The farm workers will just need to retrieve them from the conveyor system as their first action of the day so that the belt is ready for sending harvested food to the food processing  building.

In addition to the imported prokaryotes in the soil, a small number of species of flying insects and a small number of types of spiders will be brought into the farm cylinder across all levels. Once there are a good number of farms, perhaps one or two hundred, we would import from Earth some robins and sparrows and perhaps one or two other birds, and let them free in the farm cylinder. This way the human workers will have some bird song to keep them company. I think of robins and sparrows as they seem to be the most adaptable in my neighbourhood.

To help the birds along, on every farm scattered within the goat and chicken hectares, a few species of tree can be planted, ones that don't grow higher than 4m. For the goat hectares, these trees would need to be planted as early as possible as otherwise the goats will simply eat the seedling. Perhaps some goat fence can be put around the early trees to protect them from the goats.