Originally, the SPORE Shield Wall (SW) was going to be the outer construction protecting the inner iron Pressure Hull (PH). (See SPORE Design 1). The SW was going to be constructed first, with PH construction following right after. Now, I’m thinking that a single pressurized SW would be quicker, more efficient, and allow Homesteaders to create much larger spaces.
The first step in designing the Shield Wall is to lock in a construction material. Researching the construction material options will all help determine if a pressurized SW is possible. The key criteria for SW materials is that they are 100% sourced from Lunar material. The whole Lunar Homesteading concept is flawed if our Homesteaders have to import the materials needed to make their homes.
The materials I’m going to research include:
- Cast basalt – This is currently my top pick.
- Hewn basalt blocks – Pretty unlikely but you never know.
- Glass composite – This is my second favorite (based on the little I know).
- Sintered regolith – I’m pretty sure this won’t have the mechanical properties we’re looking for but I want to confirm this.
- Lunar iron – We might end up putting the iron pressure hull directly against the regolith/mega-regolith if a suitable material isn’t readily available for the Shield Wall.
The next step is to define the environment the SW will have to operate in. That way we can determine if the SW materials are suitable. Some parameters are:
- Thermal swings
- 1/6 gravity
- Regolith mechanical parameters
The third step is to figure out the most efficient design for our SW. It’s got to be a fine balance between:
- Materials needed
- Tools/equipment needed
- Labor (time and effort)
- Safety (of the construction and of the construction crew)
- Flexibility/adaptability/ability to respond to environmental changes
The fourth step is to figure out how to seal the SW so it can hold atmospheric pressure. This step isn’t really necessary if we’re going to end up using an internal iron PH. But I’d really like to find a way to make the SW also act as a PH.
Some of the ways I’ve come up with are:
- A thin layer of molten basalt – Hot and dangerous!
- A thin layer of molten glass – Also hot and dangerous!
- Basalt and/or glass “welding” of seams – Not really sure how to do this
- A thin layer of soft iron beaten into the seams
The fifth step is determining how the SW will be maintained. Everything eventually breaks. Moonquakes could cause the atmospheric sealant to crack. Or part of the SW to fail. There could be an explosion or a fire. The point is that we need to figure out the tools and techniques our Homesteaders will need to repair their Shield Wall.
The last step is to put it all together. Figure out which solution is the best for each step. Create a comprehensive plan on how to create a SPORE Shield Wall from start to finish. Create a working scale prototype from raw materials to functional Shield Wall. And put this part of SPORE “on the shelf”.