Version 1.4 August 10, 2020
The Shielded Pressurized Oxygen Resource Extraction (SPORE) project is my attempt to come up with a better way for Homesteaders (Lunar and otherwise) to extract the resources they need from their local environment and to create habitable space. For Lunar Homesteaders this would mean dealing with the regolith and the underlying mega-regolith.
In biology, a spore is a one-celled, reproductive unit adapted for dispersal and survival for long periods of time in unfavorable conditions. Like a spore, humans can take the SPORE technology and techniques anywhere in the solar system (which is pretty hostile to Earth life) and establish a Homestead. Using SPORE, they will be able to safely extract the resources they need while simultaneously creating critical habitable space.
I was working on the regolith characterization of Phase 3 of my Lunar Iron Project, Lunar Regolith Moving Equipment, when I realized something. Three things actually.
- Surface mining operations present many challenges. One of the primary reasons (among many) why we don’t currently have Lunar mining is because it’s so hard. Check out Lunar Surface Mining Challenges for more information.
- Exact replication of Lunar surface conditions is practically impossible on Earth. It’s very difficult to replicate the Lunar regolith with Earth-based simulants, let alone all the environmental hazards.
- I was going down the same path as everyone else. Trying to figure out the parameters (regolith characteristics and surface conditions) and the technology to overcome them (robotic regolith movers, drag lines, slusher mining, etc.). It occurred to me that I need to try something different. Something unconventional. Because Lunar Homesteading is unconventional.
The SPORE concept will constantly evolve. Check out the SPORE Outline page for the most current information. Please let me know if you see something here that doesn’t look right and I’ll update it. I’d also love any feedback (positive or negative) or suggestions in general. Thanks.
SPORE presentation PDF (with lots of additional information in the Appendix)
Lunar mining operations conducted inside a sheltered and pressurized structure can mitigate or eliminate all of the challenges presented by Lunar surface operations.
If Lunar surface operations are so dangerous and challenging then I should find a way to avoid them. List as many problems as I can find, find ways around each one, and figure out how to put the solutions together in a way that makes sense and doesn’t create even bigger issues.
- I know this idea is “out of the box”. Conventional thinking is taking forever to get us there. There’s other people out there researching the conventional approaches. Lunar Homesteading is an unconventional idea that demands we follow the road less (or not) traveled.
- I’m not stating that this is a completely original idea. A lot of very smart people have spent decades thinking about this topic. I’m sure someone has already thought of this. That said, I’ve read an awful lot books and papers on this subject and I don’t recall reading about something like SPORE. Let me know if you have any references. I’d love to read them.
- I make no claims that SPORE is feasible. It’s probably not. But I’m going to run with it until I come across a scientifically proven deal breaker.
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. They would be a lot more efficient (and protected) if we could put a shield between them and the sky. They would be even more protected if that shield had a significant amount of mass on top of it.
- Dust from other surface operations and electrostatic storms will be minimized or eliminated as the mining operation is contained. Dust inside the shield wall will be dealt with in the Pressurized Oxygen section.
- Radiation will be minimized or eliminated with a thick enough regolith blanket or other shielding material.
- Meteoroid impacts will also be minimized by putting mining operations under a shield and regolith blanket. Of course something big could still punch through, or collapse, the shield. But we can safely ignore the small stuff (which is the most common threat anyway).
- The temperature under the shield would be constant, even if we didn’t pressurize it. Blocking out direct sunlight will keep it cold and we can pump in waste heat to warm up the area. Of course, we are pressurizing it so we’ll have more flexibility in temperature control.
- The 14 day light and dark cycles are going to be a problem for almost all Lunar Homestead operations, not just mining. The only way to solve for it is to have enough power generation and storage available to make it a non-issue. That’s another project! But at least the 14 days of intense heat and cold are taken care of.
- Regolith covered shield should be less vulnerable to moonquakes than exposed surface mining operations. At least with SPORE, Homesteaders can retreat back to a habitat without having to cross a lot of open terrain. Homesteaders will have a chance to reach safety before a shield fails. Of course, we also need to engineer them to be sturdy when they aren’t being used for mining operations (when they are protecting habitats instead). So this is something we would have to do anyway.
- Operating in an enclosed space might even help with the low gravity. We may be able to temporarily secure the mining equipment to the shield, allowing the equipment to work more efficiently.
- We won’t need complex and expensive robots to do our dirty work. Which also takes care of the time delay remote control problem. We can, and should, still use robots but they can be far simpler (maybe even built on site) and controlled locally. We should definitely use simple robots to place the regolith blanket over the shield. No need to expose people for that.
- Sprawling surface operations aren’t possible. The mining activities will have to be smaller scale unless the Homestead is running multiple operations under multiple shields. This isn’t necessarily a bad thing as Lunar Homesteading is all about small scale.
- 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 Helium 3 or free metallic iron. 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?
- Homesteaders will have to construct the shield first, before starting mining operations. The initial shield will most likely be a lightweight framework brought from Earth.
Need to research:
- I’ll need to figure out how to keep the internal pressure from blowing the shield wall off the Lunar surface (talk about sudden depressurization!).
- Material of shield wall.
- Thickness of shield wall.
- Design of shield wall.
- Necessary regolith thickness and loading pressure.
- Loose regolith vs bagged vs sintered vs none (use glass or basalt blocks maybe).
- Supporting the shield wall as regolith and mega-regolith is excavated downward and sideways.
- Moonquake resistance.
- How our Homesteaders are going to move and place the shielding over the shield wall.
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 engineering challenges get significantly easier even with a small amount of atmospheric pressure. The equipment doesn’t have to be as specialized and our Homesteaders might even be able to operate without pressure suits (depending on the optimal atmospheric pressure).
- 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 most 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). I’ll need to figure out how much we could lose as the oxygen leaks out through the exposed regolith and mega-regolith.
- The dust problem is minimized further because we are digging down instead of across. Particle sizes increase with depth, meaning there is less of the fine dust. Dust should be minimal once we reach the mega-regolith.
- It may be easier to capture volatile gasses from the regolith using the SPORE method. We could capture released gasses by constantly cycling the oxygen in the mining area thorough some kind of scrubber. It might also not be worth the effort, especially if we are focused on reaching the mega-regolith instead of processing huge areas of regolith.
- The presence of some atmospheric resistance might help a little with overcoming the low gravity. It would be minimal at best.
- I don’t know yet if the SPORE concept will help mitigate the abrasiveness of the Lunar regolith. Even under pressure the rocks will be sharp. It can’t hurt though.
- I’m also not sure if SPORE will help alleviate the problem of regolith interlocking with itself. Again, I can’t see how having an atmosphere will hurt.
- 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.
- It will be much easier to construct habitat pressure hulls inside a shielded, pressurized environment. The oxygen inside the shield will be recovered once the habitat is sealed. Eventually the atmosphere between the shield wall and the pressure hull will reach equilibrium between the leakage from the habitat and the loss through shield.
- 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. Regolith and 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 regolith and mega-regolith. Mining operations will need to make up the oxygen loss. This shouldn’t be a problem if we are refining basalt, ilmenite, or olivine. I’ll also look into ways to seal the shield and the exposed regolith that isn’t currently being mined. Ice might be a solution.
- 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.
Need to research:
- The minimum pressure needed to mitigate the risk of fire while providing protection and eliminate the dust threat.
- The rate of pressure loss through regolith and mega-regolith. We’ll want to minimize this.
- Using water to suppress Lunar dust.
- Scavenging released regolith volatile gasses.
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.
- 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). Each mining enclosure will have a limited amount of regolith to deal with before it gets into the mega-regolith. 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.
Need to research:
- Gather as much data as we have on the regolith and mega-regolith.
- Figure out suitable simulants for the regolith and mega-regolith.
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 regolith and mega-regolith from the enclosure and move them to the processing equipment. 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 regolith and 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. Try using a shovel on the surface while wearing a space suit!
- 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.
Need to research:
- Mining equipment designed to operate in a low gravity, 100% oxygen reduced pressure environment. We’ll need manual and powered tools to:
- Scoop up regolith.
- Break up mega-regolith.
- Transport regolith and mega-regolith out of the mining area to the processing area.
- Using water to extract Lunar regolith and mega-regolith.
- Simple robotic assistance might be necessary. On the other hand, if someone is running the robots they can just as easily grab a shovel. Maybe that’s a good job for kids, elderly, pregnant, or injured/sick Homesteaders. I may eventually work on designing mining robots but for now I’m sticking with hand tool.
SPORE operations could continue even when the Homesteader are mining horizontally thorough the mega-regolith. It won’t be like mining through solid rock. They’ll still need to construct walls to support the material above and iron pressure hulls to house people and equipment. Eventually larger settlements could reach solid rock. Maybe then they can carve living spaces directly out of the rock. Until then, SPORE will allow them to create surface and subsurface living spaces as well as extract critical resources. All while being safely protected from the hostile surface environment.
SPORE at a glance – No frills description.
SPORE Project Outline – Details what I’ve learned and what I still need to work on.
SPORE Project Goals – The goals of the project.
SPORE Project Expenses – Research costs money.
SPORE Project Posts – All the posts involving the SPORE Project.
SPORE Project Updates – All the updates I have posted.