Research projects are the main reason Lunar Homestead exists. There is so much we need to figure out before permanent human settlements on Luna (and anywhere else besides Earth) are a reality. You would think that after all these decades we would be further along.
Shielded Pressurized Oxygen Resource Extraction (SPORE)
Lunar mining operations conducted inside a sheltered and pressurized structure can mitigate or eliminate all of the challenges presented by Lunar surface operations.
The SPORE project is a component of my larger project, Lunar Iron (see below). I was working on Phase Three – Lunar Regolith Moving Equipment when I started to realize that I was going down the same rabbit hole everyone else has disappeared into to. Mining the regolith on the Lunar surface is HARD. There are a lot of problems that make it extremely challenging. Check out the Lunar Surface Mining Challenges page for more information.
For the past 50 years engineers and scientists have tried to figure out ways to safely and efficiently gather and refine the Lunar regolith. There’s been lots of ideas and papers on the subject. Even some basic experiments. NASA even has an annual Robotic Mining Competition. But we still haven’t mined anything yet.
The way I see it the current paradigm has three huge flaws that make it really hard to establish Lunar mining:
- Regolith is the medium of choice. It’s pre-crushed and easily accessible. The Lunar regolith can contain all kinds of goodies like metallic iron, glass, and needed volatile gasses. All true.
- THE PROBLEM – Regolith mining is surface mining. I’ve already covered why Lunar surface mining is so difficult. Plus, the regolith in the marias isn’t particularly deep. The average mare regolith depth is estimated to be only 4-5 meters thick (Lunar Sourcebook, pg 286). So instead of digging down, we’ll have to spread the mining operations out across the surface. And the surface is dangerous and difficult.
- Robots are the preferred miners. The surface is dangerous so we want to minimize human exposure. Plus, there are never enough astronauts available to do all the work expected of them. And robots are very cool. These are all valid points.
- THE PROBLEM – Engineering robots that can handle the surface environment for long periods while doing everything we want them to do is a really tall order. And expensive. We’ve already waited a long time for our technology to get better. We could end up waiting a lot more. Robots are good but frontiers are build on manual labor and hard work. And a lot of sweat.
- Resource extraction is measured in tons per day (or even per hour). I get it. Bigger operations are usually more efficient. You can get more resources extracted per person than a much smaller operation.
- THE PROBLEM – Large operations are more complex. The equipment is more massive and takes up more space. Larger equipment also requires more energy. Nothing wrong with ramping up the mining operation once the settlement has the infrastructure and personnel to sustain it. We need to start much smaller. Something one or two people can run and maintain.
A fourth paradigm problem is that everyone is planning for a small, limited outpost crewed by professional astronauts. When has a frontier ever been settled that way? But that’s more of a Lunar Homestead thing.
The solution (well a possible solution)? SPORE!
Check out the Shielded Pressurized Oxygen Resource Extraction (SPORE) Overview page for more information.
Lunar iron can serve as the primary construction material for Lunar Homestead habitat pressure hulls.
Why is iron my first project for Lunar Homesteading you ask? Because the most critical component (aside from the people) is pressurized shelter. Sure, a functioning homestead needs lots of other technology but no pressure hull equals no people. And you can’t have a homestead without people. Besides, we need a cool container to put all the other nifty gadgets into.
We can build pressure hulls out of many other materials besides iron. But iron has a unique combination of qualities that makes it the obvious (at least to me) first choice for Lunar, and most other, Homesteaders.
Some of the characteristics of Lunar iron that make it highly desirable are:
- We know iron. Humans have been using it for thousands of years. We know how to make tools, parts, and even pressure hulls with it.
- Elemental iron is pretty strong and durable. Alloyed with other elements (carbon, nickel, etc.) it becomes even more useful. Nature has already alloyed some of the Lunar iron with nickel (asteroids smashing into the Lunar surface). We just have to pick it up.
- Iron is a common resource both on Luna and throughout the solar system. The Lunar regolith contains significant amounts of iron, both free and in minerals. Nickel-iron asteroids are abundant. Even the iconic red Martian regolith is composed of rusting iron minerals. If we can master iron beyond the Earth, we can build almost anything almost anywhere. And we can standardize common hardware because they can all be constructed from the same material.
- Lunar iron should be relatively easy to obtain (needs experimentation). Free iron can be found throughout all of the Lunar surface. See all those craters covering the Lunar surface? All of them were caused by things hitting Luna at high velocity. This resulted in quite a lot of free iron being generated (through reduction of the regolith) as well vaporized iron from the impactor being scattered all over the place. We don’t need to mine or refine this iron. All we need is a magnet. Well, we actually probably need to process it a bit before it’s usable.
- Refining iron from the iron oxides found in Lunar regolith is a relatively simple process (at least on Earth!). Doing it on Luna will be trickier but it will still take less energy and chemicals than aluminum, titanium, and most other elements bound up in the Lunar regolith. And we still don’t have to mine it. All we have to do is move regolith around.
- Iron makes a decent radiation shield. Sure, it’s no lead. But a reasonable thickness will get the job done. Mass matters a lot less once we are already on the Lunar surface. Throw some regolith on top and radiation becomes much less of a problem.
- Iron is easy to build with and repair. Again, we’ve been doing it for a very long time. We know how to cast, forge, weld, and sinter iron. We can even use it in 3D printers. Of course, we’ll need to learn some new tricks to do all that on Luna.
- Homesteads are going to need storage tanks before we start extracting oxygen, hydrogen, and all the other stuff we need. Even simple water tanks are going to be important. Storing pressurized gas is much easier than dealing with cryogenic liquids. We can make both pressurized and non-pressurized storage tanks from iron.
Other options for Lunar habitat construction (basalt, sintered regolith, aluminum, titanium, lunar concrete, etc.) just don’t have all the advantages of iron. At least that’s what my preliminary research shows. Part of this project is to quantify all of iron’s advantages and prove my hypothesis that iron should be a primary resource for Lunar Homesteaders.
Here’s some more applications for iron.
It’s time for the next project once I can show how our Homesteaders can go from raw regolith to finished habitat pressure hull. I think the next project should build on this. After pressure hulls we’re going to need other containment vessels. We’re going to be extracting all kinds of gases (oxygen, hydrogen, nitrogen, etc.) while we’re getting iron. We’re also going to be producing water (the best way to store oxygen and hydrogen). We need a way to store these critical resources. We’re also going to need other types of surface shelters.
Hey! I just started.