Version 2.1 August 18, 2023
The Shielded Pressurized Oxygen Resource Extraction (SPORE) operation is a better way for Homesteaders (Lunar and otherwise) to safely extract the resources they need from their local environment and to create habitable space at the same time. SPORE eliminates, or significantly mitigates, all of the threats and challenges of operating on the Lunar surface.
Lunar mining operations conducted inside a sheltered and pressurized structure can mitigate or eliminate all of the challenges presented by Lunar surface operations. See the Lunar surface mining challenges page for more information.
- SPORE operates primarily in the Lunar mare mega-regolith, the layer below the regolith.
- The SPORE mining area maintains a habitable environment of 100% oxygen at 48 kPa.
- SPORE is a modified tunneling shield. As mining operations move forward, a habitat pressure hull is built behind it.
- Iron extracted from the mare basalt is used to create habitat pressure hull components.
- SPORE can be used anywhere but we’re going to design it for the Apollo 12 site first. (See Lunar Homestead Experimental Location for why this site was selected)
- You can learn more about the Shielded component from episode 8 of Settle the Solar System.
- You can learn more about the Pressurized Oxygen component from episode 9 of Settle the Solar System.
- You can learn more about the Resource Extraction component from episode 10 of Settle the Solar System.
- You can learn more about the Habitat Creation component from episode 11 of Settle the Solar System.
- SPORE Mars – Presentation at the Mars Society 2020 Virtual Conference – SPORE adapted for use on Mars
Features of SPORE
Many of the challenges associated with Lunar surface mining (and operations in general) exist because the equipment and/or personnel are exposed to open space on the surface. The solution is to move as many operations as possible underground.
- Eliminates the danger of Lunar regolith dust.
- Dust inside the SPORE work area will be dealt with in the Pressurized Oxygen section.
- Radiation will be eliminated because the SPORE work area and Homestead are located at least 10 meters below the Lunar surface.
- Meteoroid impacts will also be minimized. Of course something big could still punch through 10 meters of regolith. But we can safely ignore the small stuff (which is the most common threat anyway).
- The temperature extremes are eliminated.
- SPORE should be less vulnerable to moonquakes than exposed surface mining operations. At least with SPORE, Homesteaders can retreat back to the habitat without having to cross a lot of open terrain. And being underground should make them less vulnerable to ground motion than surface structures and equipment.
- Operating in an enclosed space might even help with the low gravity. We may be able to secure the mining equipment to SPORE, allowing the equipment to work more efficiently.
- We won’t need complex and expensive robots to do our dirty work. The SPORE work area is safe enough for humans.
- Sprawling surface operations aren’t possible. The mining activities will have to be smaller scale unless the Homestead is running multiple SPORE operations. This isn’t necessarily a bad thing as Lunar Homesteading is all about small scale anyway.
- Less free metallic iron will be collected as the emphasis is switched from regolith to mega-regolith (down instead of across). SPORE won’t work as well if our goal is to mine large amounts of free metallic iron, Helium 3, or other volatile elements.
- Which seems to kinda mess up the whole Lunar iron habitat thing I’ve been working on. Until you remember that regolith contains less than 1% free metallic iron anyway. Let’s start processing mare basalt as soon as possible instead of processing thousands of tons of regolith to get the iron we need.
- The same goes for volatiles. We would have to move and process large amounts of regolith to obtain the hydrogen, nitrogen, carbon, and other elements our Homestead needs. With SPORE we focus on the resources we can gather in large quantities (basalt, oxygen, iron, aluminum, etc.). We’ll probably need to import volatiles anyway if we want to grow the Homestead quickly so why not just build that into the plan?
The shielding component is pretty straight forward. This is the dodgy bit. The thought is to pressurize the mining area with pure oxygen recovered during the refining process. As Luna is primarily made up of oxides, we’ll probably end up with more oxygen than we need.
- Removing the challenge of operating in a vacuum is the primary reason to pressurize the mining area.
- The dust problem can be minimized or even eliminated. Since the mining area is pressurized maybe we can use a method of dust control common on Earth. We can spray down the active mining area with water. I know, it’s insane. But we could recover all of that water when we process the regolith. Either extract the water or use it as part of the refining process (to lower the melting point and/or to create a reducing environment).
- The leaked oxygen can contribute to a long-term Lunar atmosphere. It will take a lot of Homesteads a lot of years to do this but it’s feasible. Human activity is going to “contaminate” the Lunar atmosphere anyway, so we might as well use it to our advantage. I read somewhere that a Lunar atmosphere could last a thousand years or more, even if we stop deliberately maintaining it.
- Fire! Maybe. If the pressure is low enough then the risk should also be pretty low. Besides, there won’t be much that is flammable inside a mining shield. Mega-regolith won’t burn. It’s highly unlikely a mining Homesteader will hit a pocket of hydrogen (that might actually be a good thing!). Safety protocols and good design should reduce this threat to a minimum.
- The loss of atmospheric pressure through exposed mega-regolith. Mining operations will need to make up the oxygen loss. This shouldn’t be a problem if we are refining basalt.
- The escaped oxygen will contaminate the local environment for a very long time. For some people this is a big problem. Realists see it as inevitable. Leaking habitats. Rocket exhaust. Mining operations. Human activity will permanently change the Lunar environment just like it’s changed the environment on Earth. At least on Luna we’re not going to destroy ecosystems, cause mass extinctions, or wipe out native populations. We’re going to do the opposite. Lunar Homesteaders will bring life, not just human life, to a world that has been dead for billions of years.
- Homesteaders will have to get dirty. Even with robotic help, the simplest solution is to get humans directly involved with mining operations. Homesteaders will have a greater risk of being injured (or even killed). They aren’t going to have the time to pursue other activities. At least not until they’ve carved out enough space, gathered enough resources, built enough infrastructure, and brought in enough personnel. Frontiers are rough. And dirty. And dangerous. People should stay on Earth if that scares them.
The primary Lunar resources are contained in rocks and regolith. That’s where we are going to find the iron we need for habitats and tools and the oxygen we need to breathe. These resources come in three very general flavors:
- Regolith – The fine-grained, reworked surface layer. We’re going to avoid this as much as possible.
- Mega-regolith – The layer below the regolith consisting of large (>1 meter) impact-fractured breccia (from the underlying bedrock) and large-scale ejecta. We have almost no information on this resource but this is where our Homesteaders will do most of their mining (once they’ve gotten through the regolith layer).
- Bedrock – The layer below the mega-regolith. In mare regions we’re talking mainly basalt. In highlands it’s mostly anorthosite. Again, we’ve got almost no information on this resource but that doesn’t really matter because the mega-regolith can be many kilometers in depth. So we’re not going to worry about mining the bedrock for now.
- One of the advantages of using SPORE is that it might reduce the trouble caused by the variability of the regolith. SPORE mines downward, not horizontally (not on the surface at least). Of course, the mega-regolith might be just as heterogeneous as the regolith. We just don’t know.
- The mega-regolith contains much larger chunks of rock than the regolith. We’ll find large samples instead of sorting through lots of regolith to find small particles of ilmenite, olivine, or basalt. Maybe this will make the refining operation simpler. Or maybe it won’t.
- All of our samples were taken from the regolith. We have far more information about the regolith than the mega-regolith. This would be a bigger problem if we had a lot more information about the regolith. As it is, we don’t know a lot about the regolith either so we’re kind of flying blind for both geologic units.
- The mega-regolith might not hold the atmospheric pressure well. There might be a lot of gaps, fissures, crevices, and cracks that will let our oxygen quickly leak out. We’ll need to figure out ways to minimize this potential problem.
- The mega-regolith has much larger particles (>1 meter) than the regolith. We’ll need ways to excavate, fracture, move, and crush these rocks.
Alright. We now have a shielded and pressurized structure. It’s a lot safer and more comfortable than mining on the Lunar surface. Now we have to remove the material from the mega-regolith. There are several ways we can go about doing this.
- Manual – The simplest method is to have the Homesteaders manually mine using hand tools. Pick, shovel, and bucket. Everything can be 100% Lunar-made (from iron initially). Sure it’s slower but this isn’t a race. Homesteaders have the time since they aren’t leaving anytime soon (unlike a government or corporate sponsored base). The manual method will require a lot less research and resources to implement. The biggest resource expenditure will be manpower (womanpower, etc.).
- Assisted manual – A step up from simple manual tool would be the introduction of power tools. A pneumatic drill (aka jackhammer) comes to mind. I’m not sure how it would work in 1/6 gravity though. Compressed oxygen might be used to loosen the mega-regolith. Although that might be a fire hazard. The introduction of compressed oxygen into the mining area will probably make keeping the atmospheric pressure steady rather tricky. Finally, we’d have to design the equipment so we can build and maintain the gear using local resources. I personally think hand tools, sweat, and time will do the job just fine.
- Automated – Robots! It’s SPACE so we have to have robots! Sure, robotic miners would free our Homesteaders to other activities (if they are remotely operated from Earth). And they would be more efficient since they can work 24/7 (we’ll need a new saying once we’re on Luna). But they present serious logistical and maintenance challenges. Importing robots from Earth reduces our mass allowance for each shipment (meaning we can’t bring as much other stuff). Lunar industry will have to be pretty advanced before Homesteaders can build their own robots from scratch. At the very least, all the high-tech electronics will have to be imported.
- Simple technology can get the job done. No need for complex, expensive robots to work outside on the surface or inside the shield. Homesteaders can easily fabricate and repair simple hand tools.
- Power tools could be introduced to improve efficiency. These tools should be designed so they can be constructed and maintained using Lunar resources.
- Robots with a much simpler design could be used if Homesteaders desired robotic assistance. The robots wouldn’t have to operate in vacuum with temperature, radiation, meteoroid, and dust threats.
- SPORE will require substantial Homesteader time and effort.
- It’s more hazardous than sitting in a chair inside a habitat commanding robots. Not a lot more but it’s still an increased risk.
- Mining efficiency will probably be lower than large-scale surface mining. But how long is it going to take for us to get to that point? Homesteaders should be able to have their SPORE operation up and running relatively quickly; creating space and extracting resources.
Phase One – Define all the components of the Shielded Pressurized Oxygen Resource Extraction concept
The first step is to figure out all the pieces needed to make SPORE work:
- Why SPORE is necessary.
- Relevant Lunar geology (selenology)
- We don’t know much about the Lunar regolith and almost nothing about the mega-regolith.
- What we do know shows the regolith and mega-regolith to be highly variable in particle size, distribution, and composition.
- SPORE needs to operate anywhere on the Lunar (and other) surface. The local geology needs to be largely irrelevant. Clever design is going to be the key to making SPORE work.
- However, it could be useful to run oxygen leakage and excavation experiments using a range of simulated regolith parameters. The data may not be of much use to actual Homesteaders but could be useful for “Proof of Concept” papers. Or even for building prototypes.
- I had decided that the Lunar Homestead Experimental Location will be based off of the Apollo 12 data. But that was before I came up with SPORE. I was more focused on the regolith but with SPORE the mega-regolith is much more important. This document is just a historical reference now.
- The SPORE Apollo 12 Regolith and Mega-Regolith Characterization page is where I’m going to park all the data I can find on, wait for it …., the Apollo 12 regolith and mega-regolith. I’ll probably do a similar page for the other five Apollo sites. I plan on using this data to run oxygen leakage and excavation experiments.
- SPORE design
- Version 1 – I had originally thought the Pressure Hull and the Shield Wall would be separate components. Now I think they should be the same thing (the Shield Wall IS the Pressure Hull). This page lays out the advantages and disadvantages of both.
- Version 2 – This page I move from burying habitats (the current paradigm) to creating habitats while tunneling. I note the advantages and disadvantages of both ideas.
- SPORE Surface Functions – Some Homestead functions must be located on the Lunar surface. This is a working list of these functions.
- SPORE physical components
- Habitat Pressure Hull
- Cast Basalt
- Cast Iron
- Construction tools
- Maintenance tools
- Excavation tools
- Material transportation tools
- Habitat Pressure Hull
- SPORE techniques
- Excavation methods
- Tunneling Shield
- Dust control
- Oxygen atmosphere pressure loss mitigation
- Material transportation to processing machinery
- Shield wall construction
- Optimal 100% oxygen atmospheric pressure
- How are we going to build the pressure hull while still allowing access to more excavation?
- Existing research done on similar concepts
- On going – I’ve done a lot of research already and haven’t run across anything like SPORE. Maybe there’s an article out there hidden behind a paywall or buried in an obscure article.
Phase Two – Experiments
- SPORE Pressure Experiment 1
- The purpose of this experiment is to determine the oxygen loss through the exposed regolith. I’m not sure how valuable the data will be for actually building a prototype SPORE unit but it may prove useful for a “Proof of Concept” paper.
- The problem is three-fold:
- We have very limited data about the Lunar regolith.
- The data we have shows that the regolith is highly variable.
- We have almost no data about the Lunar mega-regolith.
- Basalt Crushing Experiments
- My original plan was to crush up basalt gravel into several particle sizes for SPORE Pressure Experiment 1. It’s been more challenging that I predicted.
- Basalt Crushing Experiment 1
- Basalt Crushing Experiment 2
- Basalt Crushing Experiment 3
- Basalt Crushing Experiment 4
Phase Three – Working (non-flight ready) scale prototype of a SPORE structure
- The goal is to have a prototype “on the shelf”. I won’t know all the steps necessary until I am further along.
Phase Four – Public outreach and education
- Scale non-functioning mockup
- Publish data and findings
- Book – written for non-scientists
- Working on it!