This is part 1 of a 3 part presentation that begins with defining the resources available on the Moon, then describing a potential process that will allow rapid implementation of In Situ Resource Utilization (ISRU) of both metals, oxygen, and volatiles (water, hydrogen, methane, etc), and finally how those will be used as feedstocks for industrial processes and transportation fuels and oxidizers.
With a new administration and a NASA administrator adamant about the return of the United States to the lunar surface, the purpose of surface operations become a source of speculation regarding motives, methods, and expected results. Is it just for science, a training ground for Mars missions, Industrialization, tourism or just another set of flags and footprints? The key to making it more than a touch and go science excursion on the way to Mars is finding useful things to do there, develop there, and export from there.
Without an expansive sense of purpose for the Moon the effort this time will die just as surely as the last three efforts and as of today we don’t really see one yet. The latest NASA presentation on the subject, by John Guidi from NASA headquarters, has little to say about lunar surface activities by humans. The timeline for the development of a human lander only begins in 2026 according to the timeline of the June presentation to the NASA FISO telecom. That schedule is shown in figure 1.
Looking at the presentation timeline above it is readily apparent to those of us who have been around a while that post Apollo space plans for the Moon have actually devolved over time. Compare the above with the Space Exploration Initiative (SEI) era of the late 1980s where an expansive plan for lunar exploration and development was developed by NASA. This can be seen here in figure 2 here in the key chart of SEI development.
This has devolved to a much lighter touch as shown by this chart from the Guidi presentation figure 1 and figure 3 below.
One thing is certain, our national leadership is fully committed to the Moon but this has not been converted into action at the NASA level. I wrote about this separation between the White House and NASA previously as it was also the case during the Bush era Vision for Space Exploration. This is a tweet from the Vice President and I have to say he does get it right, but then so did President Bush in 2004.
How can we in the lunar science and development community work to help bring this about? What can we offer in the way of rationales for lunar surface activities that help to actually bring into being what the Vice President (and President Bush in 2004 said basically the same thing) has so clearly stated? In previous blogs I went through a lot of thing things that can be done to move toward a lunar surface industrial facility and even a lunar orbital shipyard as well as site selection and the buildup of capabilities. However, there are some steps that were left out that we can go into in detail now.
This missive will deal with the industrial bootstrapping on the surface and how that influences the crucial part from the first landing missions for resource prospecting and ground truth validation of orbital remote sensing to providing the metals as an input into the 3D printing and other industrial processes which can then lead to products that can be exported from the Moon. The discussion here will also go into some other possible products that come from the metals acquisition process that could be of use (i.e. sold) for profits in space to earthly customers to products delivered to the Earth. A key point to make is that the Moon is not just one thing (or one product). It’s not just science, or exploration, or even obtaining water for propellant, its about creating an industrial system that can not only drive down the cost of lunar surface operations, helps us get to Mars and beyond, and provides us with concrete products to help advance technology capabilities on the Earth.
In the following sections I reverse how I usually write things. Usually general principles are stated and then these flow down to detailed investigations or discussions and then these are used to enunciate findings. This time the writing will begin with details, and then expand to a general exposition of how things can look in the future.
What Do We Know From the Apollo Samples?
The most important detail of all is that our decisions today regarding lunar surface activities, operations, and development are based upon a relative poverty of data compared to what is desirable to design and build an efficient systems implementation. All of our ground truth data regarding the Moon comes from the six Apollo landing sites, two Russian landing sites, (and now from the Chang’e lander, the Chandrayaan impactor, and the NASA LCROSS impactor) and some random lunar derived meteorites found on the Earth. The Apollo missions brought back invaluable samples that provide precise knowledge regarding the composition of the lunar surface in the areas where Apollo landed.
Note: Lunar meteorites provide compositional data but we have no idea where they come from on the Moon other than appearing to generally come from the Highlands regions.
The 382 kilograms (842 pounds) of rocks and regolith provides the scientific calibration for modern remote sensing missions, specimens to study to understand the origin and evolution of the Moon, and a body of lunar materials to utilize in order to develop methods for processing lunar resources into products. Table 1, from the Book “Resources of Near Earth Space” (online pdf version here) gives an indication of the bulk composition of the lunar surface at the six Apollo landing sites:
The Moon is made up of almost exclusively metal oxides, that is a metal bound with oxygen. A comparison of the bulk composition of the surface of the Earth and Moon is shown in figure 3 (from Wikipedia).
The above information is far and above what we would have had without Apollo, but still represents only a very small fraction of the lunar surface. Even within those areas the samples that were taken can sometimes be wildly divergent in mineralogy and chemical composition. It was meant to be this way as Apollo was technically a set of geological surveys and not resource prospecting missions but this divergence in samples both informs and distorts our understanding. Tables 2a and 2b show samples from a single Apollo landing site.
The two samples above represent two types of lunar rocks as the first (74275) has a high iron content (FeO), high Titanium (TiO2), and low Aluminum (Al2O3) content. Also, this particular sample is high in Magnesium (MgO). Other interesting species includes pretty high Chromium content (Cr) (4,372 parts per million or 4.372 kg/ton) vs very low content (not detectable), in the 79215 sample. Other minor elements such as Vanadium (V), Strontium (Sr), Yttrium (Y) Zirconium (Zr), and Niobium (Nb) are also present in interesting quantities. In comparison, these rare earth elements are either completely lacking or of much lower concentration in the second sample (79215). The first sample is fairly representative of a Mare Ilmenite Basalt and the second represents highlands type material in a Felspathic Granulitic Impactite. It probably was blasted there from an impact in the lunar highlands. There is some really interesting resources in both of those rocks.
Apollo 16 was the only mission to almost exclusively sample the lunar highlands.
Note: When you look up at the Moon, the lighter colored areas are the lunar highlands and the darker regions are the basaltic lunar mare regions. This is important to postulating resources at the lunar poles, as they are highlands material.
This gave the Apollo mission a truly diverse set of samples compared to the other missions that landed in the volcanic Mare regions of the Moon. Tables 3a and 3b represent some of the diversity of Apollo 16 samples.
According to the sample information, sample 60055 that makes up the material in table 3a is a Cataclastic Anorthosite, a very light-colored rock that is very high in Aluminum oxide (Al2O3), very low concentration of iron oxide (FeO) with a high concentration of silicon. High aluminum content is typical of highlands samples (from figure 3) as it more represents the older surface of the Moon. This sample also has the typically low concentration of rare earth’s and other interesting metals. Table 3b from another Apollo 16 site is much more interesting.
Sample 64815 is a Poikilitic Impact melt rock. It has a lot of minor elements and some meteoric metal content (the Ni, Co, and Ir and others). There is also a good amount (4.92 parts per million) of thorium and some (1.21 ppm) Uranium. Except for the major constituents, these are all pretty small numbers, but they add up if you are processing a lot of rock for the major metals (Al, Si, Fe, Ca, Mg, and Ti) and oxygen.
One of the things that is annoying to someone interested in these as economic resources is that the official reports are focused just on the lunar origins interest and other science questions regarding age, temperature of origin, and other interesting, but somewhat misleading foci. The Apollo missions were for science, without any resource prospecting considerations. Thus for some things, like meteoric metals, there is less consideration and much less discussion. For example the composition of sample 60615 looks a lot like the previous tables shown here in table 4.
This is all well and good and you can see that the magnesium and aluminum content is higher, but what is not told in this document for sample 60615 is the content of meteoric metal. From another document (here), you get this shown in figure 4:
Another super interesting tidbit from the same document (Apollo 16 sample catalog), is in figure 5.
Thus as can be seen, there are significant metals content from meteoric metals (kamacite is a taxonomic description of typical meteoric metal). This is very important as if you know anything about metals for 3D printing these metallic particles are within the size ranged used in those devices. This makes processing exceptionally easy as simple mechanical methods can be used to separate metals. If you look at the Apollo 16 sample catalog, most if not all Apollo 16 samples have Ni-Fe metal as part of their makeup. The same is true of the regolith. All lunar highlands regions have higher meteoric metals content than the Mare regions due to the much older age of that terrain.
The above numbers are for rocks, the regolith is much more diverse and complex in composition as it consists of small fragments and atomized “dirt” of local rocks that have been blasted off by micrometeorites. Regolith also has a lot of meteoric metal, fragments from all over the Moon, and other meteoric types. It should be the case that for every 3 grams of metal there should be over 95 grams of asteroidal rocks, just due to the general composition of asteroids in the inner solar system. Table 5 shows the soil composition from a Apollo 16 sample.
As one would expect, this sample of lunar regolith (61221) (soil) looks much like the lunar rocks that are in the same area chemically. Where it gets interesting is the volatiles in the sample. Figures 6a, 6b, and 6c provide some interesting chemical analyses of this regolith sample.
The reason for being so detailed and hammering the point home here is that the Apollo regolith samples provide irrefutable proof of enhanced volatiles that increase resources on the Moon for industrial applications. The only one of these three graphs with concentration values is 6b, but the point is that there is on the order of tens to hundreds of ppm or stated otherwise, grams per ton even near the lunar equator of these volatile species. The water in these samples during the Apollo era were mostly disregarded as being from contamination. The samples being in humid Houston this is understandable, but the recent remote sensing missions have now confirmed that the H2O concentrations are real. If they are real at the equator, the same remote sensing missions show concentrations tens to thousands of times higher even in the non permanently shadowed regions of the poles. This is excellent news!
Note, there are also agglutinates that are fused fragments of regolith, small rocks, melted rocks, and meteoric fragments. They are intermediate between regolith and rocks and there are many of these in the Apollo samples as well. Some of these have quite high meteoric iron contents by weight, some over 5% by weight metal. They also have a patina nano-phase iron. This will be discussed further in part 2 of this missive.
Here I have focused mostly on highlands resources in preference to the mare regions. This is, considering conclusions provided in previous writings, because of the lower startup capital cost of first outposts in the polar regions (highland terrain) because nuclear power is not required for significant industrial operations. As previously stated, there is also more free metals from meteorites. The Moon is rich with many resources for a technical civilization but the key is that we have to start in a region where it requires the least cost to develop, and then bootstrap from there.
What We Know From Recent Remote Sensing
Our Apollo ground truth has been greatly extended by more recent remote sensing missions. It was 21 years (1993) from the last Apollo mission before the U.S. (Strategic Defense Initiative Organization) sent a spacecraft (Clementine) to the Moon for global remote sensing as a technology development mission for anti-ballistic missile sensing. It was 1998 before the first NASA mission went back to the Moon (Lunar Prospector). Clementine had a very good set of instruments for science and produced some of the first evidence for remotely sensed water. Lunar Prospector was a mission for global science but the name was specifically chosen to connote exploration for resources and not just science. The Lunar Prospector Gamma Ray instrument provided complimentary evidence regarding lunar polar water and crucial elemental composition information. However, the water results of these missions were initially explained away with alternate interpretations and then only grudgingly accepted by many in the science community, after other missions confirmed their results.
For example, it took 40 years (from the 1960’s till post 2010) to convince some in the scientific community regarding water on the Moon via findings from Chandrayaan, Lunar Reconnaissance Orbiter, Kaguya and Galileo. Also, we now know, from the LCROSS mission that the hydrogen and other volatile signatures seen in the remote sensing data in the polar regions have a ground truth to confirm the findings. Additionally, the Apollo 16 findings for water have been validated by remote sensing [Lawrence et. al. 2015, Banfield et. al. 2018] to cover the entire highlands region of the moon. Thus it can be assumed that in non polar regions that over 100 ppm (or 100 grams/ton) of water exists everywhere in the lunar highlands. This is just a baseline, in the polar regions >5 degrees from the poles, these numbers are far higher. Figure 7a shows the results of the analysis of the LCROSS impactor plume of volatiles from Cabeus .
Similar results for water volatiles comes from the Chandrayaan impactor shown in figure 7b:
Thus we have two fairly definitive results of remote sensing of impact plumes in the polar regions from recent missions. Other remote sensing results build upon this data as well as from Apollo ground truth. A representative of this are the results from the Chandrayaan Moon Mineralology Mapper (M-cubed) shown in figure 8.
There is a growing corpus of papers on this subject of water in the polar regions of the Moon, both for concentrated forms and for more diffuse forms spread over large areas. Here is another Spudis graphic showing in figure 9 overlapping and confirmatory findings for water in certain polar craters.
Another related though finding pertains to large metal impacts on the Moon. As was discussed in my book “Moonrush“, there should be a fairly large impactor from a metal asteroid approximately ever 1500 square km. There should be a remote sensing way of finding these large metal bodies and a high powered radar is one of those ways. Figure 10 shows anomalous Circular Polarization Ratio (CPR) from the same data for the water in the polar regions.
I hope that the reader, no matter the level of technical knowledge, can understand here is that there are a lot of resources on the Moon, and that in the last 10 years now with many new lunar missions our remote sensing is much improved, and is much more believable due to the Apollo and impactor ground truths.
Here is a link to papers that go into more detail on the water.
Elemental Compositions From Remote Sensing
Two charts presented in figures 11a and11b are from remote sensing based on the ground truth of the Apollo samples. With the known spectral characteristics of the returned samples and the known physics of how certain lunar situated elements fluoresce in X-Ray, Gamma, or infrared, it is possible to definitively catalog at the elemental scale some lunar resources, such as titanium, iron, and even thorium. It goes without saying that all lunar resources are going to be also made up mostly of oxygen and silicon, since it is in high concentrations in all rocks as the previous tables show.
These are elemental concentrations, telling us nothing about the minerals that these elements are bound in. That information comes from the Apollo ground truth! Our ground truth for elemental compositions is more sparse in the polar regions due to the nature of the instruments (gamma ray and x-ray) that gained this data. Since in the near term we want to focus on the polar regions, this is shown to indicate that remote sensing does provide a lot of information on elemental abundances.
What are the intrinsic resources of the Moon? On the Earth this would be air, water, Earth, all things that have been basically free, and the foundation for life and society here. There are many books that go into the advantages of these resources and it is no surprise that just about every powerful ancient civilization’s capital city was located on a river.
On the Moon the intrinsic ones that are key to future industrialization are simple, light and vacuum. Where there is abundant light, such as at the poles, there the costs for industrialization are lower than in areas where there is two weeks of day and two weeks of night. My paper on Site Selection for Lunar Industrialization has the numbers for what lunar polar power systems will be able to provide compared to the non polar regions. This shifts over time, but until the late 2020s will be accurate. Table 6 provides the numbers for the various locations.
The power (or total energy) available in the polar regions is more than twice that available in non equatorial regions. This saves a lot of money on solar power installations and doubles the amount of power available for industrial activities.
The second intrinsic resource on the Moon is the vacuum itself. The 1 x 10^-12 torr maximum vacuum is an amazing resource for industrial activities. The vacuum materials market globally is worth several tens of billions of dollars per year. One of the issues that will become very apparent in part 2 of this missive is that a particular method of separating metals and oxygen (Vapor Phase Pyrolysis) becomes easier and occurs at lower temperatures the better the vacuum. There are many other advantages of this hard vacuum that will be discussed.
Summary and Lead In to Part II
It is hoped that by now it is abundantly clear to the reader who is not a technical and scientific professional that there are very significant resources on the Moon. These resources are in metals, metal meteorite fragments, and water. There are many rare elements, including radioactive thorium and uranium present on the Moon that are exploitable. The key is how do we get there, how do we exploit them to build a sustainable and profitable lunar industrial system.
In part 2 I will go into the processes for processing lunar materials for resources in metals and volatiles such as water and other hydrogen bearing gasses show earlier here. The easiest will be mechanical methods for separating meteoric metals. The next will be simple baking to 1,000 degrees C to boil off the volatiles. Finally, Vapor Phase Pyrolysis will be deeply investigated for its advantages. It should be noted that there has been a lot of work done regarding using chemical methods. It is my opinion that at some point these will become more economically efficient. However, our focus is on the early days, and there are some great findings on Vapor Phase Pyrolysis that shows that much has been done to advance this technology since NASA’s last great work in this area in the early 1990’s. It has the potential to be far easier and more cost effective to do so in the near term. That is for next time…