Partially obsolete
I still haven’t figured out whether it’s better to have the pressure hull separate from the Shield Wall or integrated. But I have decided that moving regolith to make the protective regolith blanket is a bad idea.
Most designs (including SPORE up to now) have the majority of the Lunar base/settlement buried under 4-5 meters of regolith. This is smart as it protects the habitable areas from:
- Radiation (solar and cosmic)
- Impacts (especially the constant rain of very small particles)
- Thermal swings (by blocking direct sunlight)
- Dust (once the protective regolith blanket is in place)
The problem is that we need to conduct surface operations to cover the habitats with regolith (see Lunar Surface Mining Challenges to learn why this is a difficult thing to do). Either we have to dig out a hole to place the habitat into (and then cover it up) or we have to push a lot of regolith over the habitat (forming a hill).
This isn’t good for a number of reasons:
- Either technique is going to take time. Time that our people and sensitive equipment are exposed to surface hazards. Sure, some ideas call for tele-operated robots to do all the work before humans show up. But without human technicians, the robots have to be very durable (increasing their complexity and expense).
- Both techniques require expensive and complex machines (usually robots) to move the regolith. Robots that have been in development for decades (and are still not operational).
- Both techniques stir up a massive amount of dust. We absolutely want to avoid this!
- The regolith isn’t very thick, especially in the marias. In some places we think it’s only a couple of meters deep. So we could end up digging a hole AND covering the habitats. That seems like an awful lot of effort.
- It’s hard to expand the settlement using these designs. We’ll have to keep the ends exposed (increasing the surface risks) so we can add new sections later.
- Many concepts incorporate refining the regolith with moving it. The idea is that we’ll extract the usable resources and use the left0vers to cover the habitats. The SPORE concept also used this idea initially. I’ve come to think that the Lunar regolith is a trap though. Instead of trying to design for it’s use we should be designing to avoid it (and avoid disturbing it) as much as possible.
SPORE design version 2
My thinking goes like this:
- Create the access tube and hub as quickly as possible. This does two things.
- It gives the Homesteader a place to retreat if a solar storm kicks up (5-6 meters of regolith overhead).
- It provides some raw material for the small Solar Forge (another idea I’m working on) in the Homestead “pod” that came from Earth.
- Then the Initial Habitat is carved out and outfitted.
- Now the Homesteader has a much more comfortable (and safer) place to live while building the rest of the Homestead.
- Move as much equipment from the Homestead “pods” as possible into the Initial Homestead.
- Now the Homesteader can start creating additional habitable space to hold storage tanks, work areas, processing equipment, etc. (Expanded Habitats).
- The traditional thinking is to place storage tanks on the surface under a “ramada” or other structure to protect them from the Sun and to take advantage (?) of the Lunar vacuum. I think that only the things that HAVE to be on the surface should be. Everything else should be underground inside habitable spaces. Sure, it means that our Homesteaders will have to carve out more habitats. And that they will have to import the nitrogen to fill them. But putting as much equipment inside has huge advantages:
- None of it has to be hardened to vacuum, radiation, etc. And most of the gear can conceivably be manufactured by the Homestead.
- It can all be more easily maintained and repaired. Ask an astronaut how easy it is to get stuff done in a spacesuit.
- The Hub would have four access points so there would be 3 Expanded Habitats and the Initial Habitat.
- The traditional thinking is to place storage tanks on the surface under a “ramada” or other structure to protect them from the Sun and to take advantage (?) of the Lunar vacuum. I think that only the things that HAVE to be on the surface should be. Everything else should be underground inside habitable spaces. Sure, it means that our Homesteaders will have to carve out more habitats. And that they will have to import the nitrogen to fill them. But putting as much equipment inside has huge advantages:
- The next step would be to increase industrial output by creating a larger Solar Forge on the surface.
- Create another Hub at the end of one of the Expanded Habitats.
- Create the Solar Forge habitable space but don’t seal it yet.
- The Solar Forge is where we’ll use concentrated sunlight to heat Lunar material.
- Create the sunlight conduits for the Solar Forge.
- Another idea I’m exploring is to remove all the sunlight collectors and power plants from the Lunar surface as well. All we need is concentrated sunlight. It should be possible to pipe sunlight down to the Solar Forge
- Seal up the Solar Forge and get it operational.
- The addition of a larger Solar Forge will allow the Homestead to create more habitable space and equipment faster.
- From there it’s just a matter of adding more space, more industrial capability, agriculture, etc. And more people.
I’m not worried about the actual shape of the Homestead yet. I figure we’ll eventually have a handful of standard designs that Homesteaders can pick from.
Advantages of this design
- The “Shielded” component of SPORE is baked right in from the beginning. Surface activity and interaction will be kept at a minimum. Homesteaders and equipment will have protection from the start.
- Can still use either an iron pressure hull or an air-tight lining to create habitable space. I’ll still have to work on that issue.
- Should simplify the engineering a bit. Instead of figuring out how to construct stuff on the surface (and deal with all the hazards there) we just have to learn how to dig through the regolith and mega-regolith and how to build spaces that don’t collapse. It’s not as much about architecture as it is about mining.
- Maybe there will be less oxygen leakage because the habitats are already under 5-6 meters of compacted regolith.
- I’m sure there is more but that’s all I got at this moment. Let me know if you think of any.