Welcome to the Sunday Paper Club. Every Sunday, this blog will offer an analysis of a paper on space habitation and other related topics. These are my opinions on a weekly scientific paper; basically, I read the paper and write down my thoughts while I read it. They are subject to my perspectives and believes. I am open to debate, so if any reader believes I have misinterpreted something in a paper, please point it out. I'm only a student and I'm still learning how to read these papers and interpret them. All quotes and ideas are from the paper, unless otherwise noted.
This week we are reviewing the paper Report of Workshop on Methodology for Evaluating Potential Lunar Resource Sites. I am using a new format based on the Lifehacker article Back to School: Keep an Academic Reading Journal.
Article Information
Title: Report of Workshop on Methodology for Evaluating Potential Lunar Resource Sites
Author(s): Richard Williams and Norman Hubbard
Date: February 1981
NASA Technical Memorandum 58235
Article Overview
This paper starts with assuming a Space Solar Power (SSP) campaign will take place. Then it goes into detail what technology and information is needed to set up a moon base to mine for resources needed in a SSP satellite. There is also a detail explanation of methods for prospecting on the moon, including ways to prospect for the moon's orbit. It also finds ways to apply what was learned during Apollo to find mining sites.
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Quotes and Analysis
"The workshop analysis examined five major topics - lunar resources geological studies, geophysical studies, geochemical instrumentation, and robotics" Page 2.
"A polar orbiter with a variety of remote-sensing instruments would be launched to survey the entire Moon and, depending on what was found, one or more rovers would be dispatched to confirm and map in detail the deposits of highly concentrated resources" Page 3.
Comment: This allows for extremely cheap and quick prospecting of the moon, as opposed to manned crews. This report was written in 1981, so I'm not sure whether this was done before, but having this map could bring about a profitable moon base. The first moon base will most likely be built near the highest concentration of useful minerals on the moon. Placing a moon base here would be for more significant then building the first moon base because a moon base placed in the richest part of the moon can be useful for longer.
"if very large structures of relatively low inherent complexity are to be constructed for either applied or research use, it may be desirable to use lunar materials in their construction [whereas complex structures should be made on Earth]" Page 4.
Comment: This implies we will never see the great glass domes on the moon, what is most likely to be constructed on the moon are bases in lava tubes and/or lunar soil covering some form of structure. A prefabricated moon base would blow the cost of the ISS out of the water, thus, moon bases will be as simple as possible.
"Theoretically, the energy required to go from the Moon to geosynchronous orbit is only 4.5 percent of that required to go there from the Earth's surface" Page 4.
Comment: I was really stunned to know that it was this big of a different.
"...the materials that are needed to construct an SPS [Solar Power Satellite] are mainly the same as those necessary to construct the other systems" Page 4.
"[A Space Solar Power(SSP)] construction program needs nearly 10000000 megagrams (10000000 metric tons) of satellite-specific material" Page 5.
Comment: This might be a deal killer for SSP, will these is that much material on the moon, the program will depend on a highly efficient process, else you'll need more then one mining site, which means more then one base and higher costs.
"Glasses, fused silica, or silica with minor additives account for 30.3 percent of the amount needed [for SSP construction]; silicon, for 15.1 percent; aluminum 9 for 11.4 percent; and ironfor 5.7 percent" Page 5.
"Oxygen should be a natural byproduct of metal recovery from silicates and oxides and thus is not considered explicitly as a resource" Page 5.
Comment: This is a huge deal because this base could easily produce fuel with little burden on the facility.
"Of the materials needed for large-scale satellite systems, the easiest to obtain will be the glasses, which can either be extracted from the regolith or formed by fusing the soil" Page 6.
"...carbon, hydrogen, nitrogen and noble gases ... tend to be most concentrated in the fine-grained soil fraction. Other volatiles such as chlorine, fluorine and sulfur, are known to be concentrated in the dark mantle material and in regions with orange soil (such as the Apollo 17 site)" Page 7.
"...zinc, cadmium, indium, mercury, lead, germanium and the halogens...are often found in considerably higher concentrations in areas shadowed by large rocks and on grain surfaces of the finest grain sizes of soils" Page 7.
"Solar protons (and other solar products such as noble gas atoms are found implanted in lunar soil particles, mostly within a few hundred angstroms of the grain surface, where they can be easily extracted by heating the soil to a few hundred degrees centigrade" Page 7.
Comment: This is really cool because we have an abundance of a volatile gas on the moon, this means we will not have to bring these important gases to a moon base. This could mean an abundance of hydrogen and helium for fuel and argon for industrial proposes. If the moon base uses a magnetic launcher, the noble gases will be needed for coolants.
"The topography of a candidate mine site must be known within a resolution of 10 meters for detailed planning of the mining operation" Page 10.
"Possible measurements that can be obtained from orbit are gravity, magnetic field, infrared, microwave emission, and active radar" Page 13.
"Electrical conductivity, or equivalent loss tangent (tan delta), is more sensitive to ilmenite [,titanium-iron oxide ore,] content than to density at frequencies greater than 100 kilohertz (ref. 22). At 450 megahertz, a regression fit was found to the Apollo 16 data of: tan delta = [(0.0015 ± 0.0012) + (0.00009 ± 0.00022)C] rho, where C is the percent of ferrous oxide (FeO) + titanium oxide (TiO 2) and rho is the density" Page 14.
Comment: This formula is a huge deal because it gives a precise knowledge of how much material is at a site. Which in turn means better mission planning leading to cheaper missions.
"The seismic refraction experiment consisted of a seismic energy source, a geophone array, and a recording system. On the Apollo 14 and 16 missions, the energy source was a squlb-fired thumper" Page 16.
Comment: I never knew about this experiment during the Apollo mission, I thought it was pretty cool they where prospecting.
"the acquisition of additional remote-sensing data will be from lunar orbit because the spatial resolution required can only be obtained that way" Page 18.
"A prospecting/assaying rover, however, must meet new requirements: (1) it must have essentially unlimited range and endurance; (2) it must be able to operate... out of sight from Earth; and (3) ... its obstacle-crossing, slope-negotiation, and crisis-extrication abilities should be as high as possible" Page 21.
"a lunar resources map covering all the Apollo photography should be constructed. The map would incorporate photogeology interpretations, sample returns, geophysical and geochemical data and meaningful correlations between these data sets" Page 26.
"...it will be worthwhile to advance the technologies affecting the mass of the processing plant 9 its needed reagent makeup rate, and its operating lifetime" 27.
"NASA's proposed scientific Lunar Polar Orbiter (LPO) (ref. 49) was examined as a candidate for the orbital resource survey and it was concluded that the mission would be well-suited to the purpose with no changes in its instrumentation and only minor changes in its operations" Page 28.
"we would recommend that resource maps be prepared for several sites using existing data, that automated systems be developed to obtain in situ physical and chemical data, and that R&D projects be conducted to test and quantify the mineral beneficiation and refining processes that have been proposed" Page 29.
Questions Raised by the Paper
Was the Lunar Reconnaissance Orbiter (or any lunar orbiter) outfitted with the prospecting tools this paper proposes?
What were the prospecting experiments conducted during Apollo?
