What to Do on the Moon
written by Steven Wintergerst on June 01, 2005 | contact me
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Being far from a part of the aerospace loop, I cannot say with certainty that any of my schemes are appropriate for lunar industrialization. These are provided as mere ideas, some more researched than others, but none definitive.
WHY THE MOON?
I have chosen the moon, not for any reasons of feasibility, but because it is the closest world to the earth. The moon is ever present. It’s size, and brightness makes it the realest of the extraterrestrial worlds in the common mind. Beyond that, manned missions to the moon are a proven fact. Having done something once makes doing it again, or at all far more attractive to politicians, who try to stick to the known possibilities.
A third reason is the unknown quantity of microbes. The moon has no microbes, but a flurry of papers, and websites have claimed that Mars probably does. The public has learned to fear, and mistrust all microbes, even the ones that let cows eat hay. Until a categorical proof of the absence, presence, and dangers of Martian microbes has been achieved, return trips from Mars will equal political suicide.
Granted, scientifically speaking, the fuel needed to reach the moon is little less than a trip to Mars, and Mars has far more resources, including materials capable of producing fuel for the return trip, but due to political, and emotional reasons, a trip to the moon seems more likely in the near future.
Visiting the moon will not be so bad. Skylab, Mir space station, and the ISS have proven that manned missions gain at least as much attention, and more prestige than any unmanned trips to other worlds, despite the science return, or cost.
Since orbiting space stations have proven viable, albeit not particularly cost efficient, a manned base on another world seems the next logical step. Missions to other worlds, in fact, are far more attractive than interstellar space.
Some have argued that the moon is too poor in resources for human habitation; however, scientific endeavors have proven that man can both live, and learn in space. The moon, resource poor as it is, certainly has more resources than space. Compared with space, the moon will be a better subject for colonization and discovery. Certainly, the moon may not prove the best target, but it will prove a better target than our previous colonization efforts.
RESOURCES: Low earth orbit, where our previous extraterrestrial bases have been built, is a particularly resource-poor section of space. There are only four resources in low earth orbit: Solar energy, Solar wind, a hard vacuum, and the earth’s magnetic field. Currently, the solar energy is used for electricity production, no efficient method of harvesting the solar wind has been designed, and the magnetic field is used only for shielding against the harshest features of the solar wind. The hard vacuum itself is not actually usable, but certain industrial techniques can be performed in hard vacuum best, and producing such a vacuum on the surface of the earth is rather expensive.
Some experiments have been conducted on using the magnetic field to produce electricity, and methods for using the solar wind, and sunlight for propulsion have had limited success, but these are not yet “proven” technologies. While I eagerly await such technologies becoming trustworthy, their current state prevents me from discussing them in any economic considerations other than as prospects. Goods produced in the hard vacuum of low earth orbit, although of great interest, currently lack an economical means of transportation for large scale production to be worthwhile.
Thus, low earth orbit really has only two “goods” that are currently used: Electricity from the sunlight, and shielding from the magnetic field. Since low earth orbit is very close to the earth, objects there are shaded from the sun almost 50% of the time.
On the surface of the moon, sunlight is not much diminished from that found in Low earth orbit. On the surface of the moon, illumination occurs only half the time, although the time between light and dark is longer. There is no magnetic field on the Moon, but there is a large supply of mass, in the form of various stones and ores.
For these reasons, a moon colony need only find radiation shielding to make it self economically competitive with low earth orbit. Such a shielding can easily be obtained through the judicious use of a shovel like device, designed to place lunar regolith over the lunar outpost. Likewise, the material resources on the moon can be utilized in a fashion more like that on earth.
Thankfully, the moon has a number of other resources. The moon has LAND. It is amazing how comforting it is to be able to build things on a surface. Such construction schemes are tried and true, and will be of great use on the moon. Travel on the moon is also far less costly than in interstellar space, thanks to the utility of human feet, and other surface mobility schemes, which need not depend on rocket fuel. Wheels, for example have been proven on three worlds, and are a far more robust, and efficient tool than rocket power.
The moon also contains a good deal of oxygen, silicon, and some iron in the lunar regolith. None of these have been found in quantities that would lend themselves to being considered an ore, but they are there, and can be obtained.
Silicon is rather useful in the production of electronic components, and solar panel arrays. In fact, everything needed for producing solar panel arrays is available on the moon.
The moon is also fairly rich in refractory materials, titanium, rutile, etc. Refractory materials can be used to make heat shields, a practical device, useful for aero braking, and reentry of the earth’s atmosphere. Thus, travel to, and from the Moon may eventually prove more economical than that from Low Earth Orbit. Such an economic reversal may prove impossible, due to the higher orbit necessary to reach before getting to the moon.
Iron, as I mentioned is also available on the moon. Actually, iron here is available mainly from the impact of iron meteorites. Little of it is available on the surface, but large bodies of it may be intact in the craters from impact with iron bodies. A little prospecting could go a long way in finding nearly pure bodies of this, which will be alloyed to some degree with nickel.
Many areas of the moon also include minerals that have trapped some quantity of hydrogen from the solar wind. Another source of hydrogen may be in cometary ice, some of which should be located in craters near the poles. This is probably not enough hydrogen for serious industrial operations, but could replenish losses of terrestrial hydrogen from industrial uses of this resource.
Carbonaceous meteorites, which would normally degrade on earth, could survive a long time on the surface of the moon. These may contain valuable materials. Some carbonaceous meteorites resemble coal, or even petroleum. The burning of hydrocarbons as a means of energy production may not be possible on the moon, due to a lack of oxygen. However, it may still be possible to produce plastics, lubricants, and various synthetic rubber, and textiles.
A number of endeavors may be possible on the moon with a little practice. Here, I will attempt to list a few of the more likely purposes that might bring people to the moon.
ASTRONOMERS: The lack of an atmosphere, slow rotational period, and low gravity all work together to make the moon a very attractive place for astronomers. Without an atmosphere, they can study the whole spectrum of light produced by any star, or other heavenly body they desire. Doing so will also be possible for most of the day, as the sunlight is not scattered, and therefore does not obscure the daytime sky.
The slow rotational period means that telescopes do not need to move as fast to track objects in the sky. It also ensures that longer exposures can be taken without fear of loosing the objects.
The lower gravity is really an incidental bonus. Refracting telescopic lenses can be built much larger than on earth, but reflecting telescopic lenses have become much more desirable. These too can be built much larger, although the real benefits may prove to be in reduced supporting structures. Some effort will need to be placed in determining exactly how much support is needed.
To get the industry started, it is my firm belief that one of Robert Zubrin’s “Tuna Can” habitats could be admirably modified to house a telescope assembled on earth. However, to achieve any real leverage, the production of lenses will have to occur on the Moon, making the use of local resources highly desirable.
Lunar astronomy may prove to have a few difficulties. Making airtight observatories has not yet been proven possible, but with remote sensing equipment, this may be a small concern. In fact, making human habitation within a lunar observatory may be superfluous, since many high class astronomers would prefer to work from home.
The slower rotation will require a different time piece from what current astronomers use. This too is not a major problem for modern science, and requires only minor engineering efforts.
A more difficult problem may be political pressure. Very large telescopes on the moon might be put to more sinister efforts, such as spying. Astronomers might have some interest in studying the atmospheric properties of the earth, and observing it to obtain a better ephemeris, but until the question of spying is resolved, large telescopes will have to be located only on the far side of the moon.
ELECTRICITY: The benefits of Helium3 fusion have been touted by many would be lunar colonists. Helium 3 is a rare isotope of the helium atom. It has been trapped in ilmenite granules on the moon over the 4 billion years of solar activity. Helium 3 can be fused with deuterium in a very clean fusion process. Helium is rather light, and one shuttle full of this product could theoretically supply all the energy needs of the earth for over a year.
Sadly, the amount of helium three available on the moon is not much more than what could fit in about ten shuttle loads. Also, the Deuterium (Hydrogen 2) needed to fuse with this helium is not available on the moon. A supply of hydrogen 2 sufficient to fuse with helium 3 would require expensive cryogenics, and shipping it from the earth would cost nearly as much energy as it would produce. Replenishing the supplies of helium 3 in the moon’s regolith would take about 4 billion years, making it a more or less non-renewable resource.
There is also the troubling little fact that fusion of helium three with Hydrogen two, although very clean, has not been performed in such a way as to produce any net energy gain. Entrepreneurs are still optimistic, but researchers have been unsuccessful in this effort since the late 1970s. Over 30 years of failure might indicate that this line of research is a blind alley.
Processing the raw ilmenite to obtain Helium 3 for export requires heating the rock to over 4,000 degrees Fahrenheit. Mirrors, heating cables, and nuclear reactors have all been suggested for this process. Most of these ideas will require a fairly large outlay of materials, and if helium 3 fusion does not prove cost-effective, it would all be wasted.
A further trouble with this scheme is that the richest deposits of helium three are in the areas that have been around the longest. That is, there is more ilmenite, with more helium three in it, in the older and more rugged highlands than in the younger and lower Mares. As discussed in other places, the highlands are more rugged, making transportation more difficult than around the Mares.
The energy necessary to process helium 3 might be more efficiently put to work in creating solar panels. Solar panels on the moon would be more efficient than on the earth, since no atmosphere, or cloudy weather would interfere with the production. The electricity could then be beamed to earth via microwave.
The energy cost necessary to extract hydrogen 3 from the entire lunar surface would probably be more than the energy cost necessary to pave the entire moon in solar paneling. While the energy production would not be immediately as great, solar panels would continue to produce energy until the panels surface is smashed apart, or pitted beyond recognition by various meteorite impacts.
This risk goes down the longer the solar system exists, and certain measures might be taken to reduce this risk. Magnetic fields, lasers, plastic coating on the panels, and large orbiting balls of foam have been suggested for such purposes Maintenance expenses for replacement due to this problem is likely to be less expensive than replacement and maintenance due to human error. All of the raw materials that go into making solar panels can be found on the moon. Current processes require the use of hydrogen in the processing. This could be limiting, but at least there is a large supply of that on earth.
Oxygen-carbon fuel cells can also be produced on the moon, in order to store power while the sun is down. This will allow the production of electricity to go on fairly well and such power could be transported to other areas via microwave, thus doing away with the need for rocket ships to transport this commodity.
Electrical production on the moon provides an attractive alternative to the usual practice of burning fossil fuels for energy, because it is an inexhaustible and reusable form of energy production. Electricity produced on the moon would also not affect the atmosphere of the earth.
One slight drawback is the possibility that beaming electricity in from the moon might raise the temperature of the earth, but this concern is comparable to that of global warming, and if global warming is to occur, I would rather it be caused by pure energy than by polluting gasses that could have other health effects as well.
GREEN HOUSES: A green house on the moon is likely to be a far more intricate affair than a greenhouse on earth, or on Mars. It may be slightly simpler than a greenhouse in orbit around some other planet though, and since people need lots of food, it is desirable to produce this food on location, rather than having it shipped in at significant costs in rocket fuel.
I suspect that the lunar poles would be the best place to set up a green house. Here, sunlight can be obtained all the time, whereas in other locations, sunlight would be available 14 days straight, followed by 14 days of total darkness. The lunar poles are also the most likely place to find relatively abundant water, and other volatiles, all useful in green house production.
Robert Zubrin (among others) will point out that several feet of glass will be necessary to shield against radiation for greenhouses on the moon to make use of natural sunlight. Such thick pieces of glass will be very heavy, and must be replaced if they become pitted, or cracked. Another option would be to make extensive use of artificial lighting. For this to be effective, a grow light factory would probably need to be built on the moon.
A large sheet of glass several feet thick is something that could make any colonist rather nervous. Special glass would be necessary, something akin to bulletproof glass, so that micrometeorites would not penetrate all the way. Even then, occasionally changing out the glass would be necessary. Perhaps several individual sheets, one over the other would be better.
A totally different suggestion might be to use fiber optic cables of a few feet in length. Such short lengths are quite easy to make. The small diameter of these cables also makes it possible to change out one or two at a time without seriously threatening the integrity of the habitat. Being fibrous in nature, they can also be woven together on the outside of the habitat, to provide some protection against micrometeorites.
Fiber optic cables might also be stretched some length along the ground, so as to modify the solar period for greenhouses not at the poles. Such a scheme works best closer to the poles, where shorter lengths of cable could increase the growing period more. Even a small gain in areas far from the pole may be worth the while.
In greenhouses beyond the poles, the sunlight could become a problem. Using rotating shade panels to give the plants regular days, and nights will work just fine during the 14 day period of sunlight. Growing things for longer than 14 days will require fiber optic cables to pipe in sunlight, battery operated electric lighting, or mobile greenhouses. This greatly limits the types of crops that can be raised.
In non-polar areas, growing plants becomes increasingly more costly, due to the rarity of sunlight over some part of the month. After extensive colonization, it may be possible to have small greenhouses inside rovers, going from town to town, following the sunlight, and selling their wares. Such a scheme sounds unlikely, even to me. The use of fiber optics seems a more likely plan, although I doubt that this would get far very close to the equator. Here, I feel that grow lights are the only reasonable alternative for large scale production.
These various arguments suggest that the polar areas will remain a major force in the food production system for years. The polar greenhouses and mobile greenhouses may eventually work on selectively breeding plants, to produce crops capable of making food in 14 days, or surviving in the dark, and cold for fourteen days. The Polar Regions may not be too enthusiastic about giving up a virtual monopoly, and may in fact fight against such efforts.
AUTOMATED ROVERS: Automated rovers could be built on the moon, and rented out to earth based research companies. This would allow terrestrial controllers to work on the Moon. Real time communication with automated rovers is possible only on the near side of the moon, but satellites going around the moon, as for mapping, or other survey work, could relay instructions from time to time to far side rovers, much like NASA currently controls Martian rovers. Such an industry is likely to be most useful for research, and science return, but eventually, rovers that could build various industrial complexes might become quite useful.
Astronomical telescopes might also be automated, and controlled in a similar fashion, and probably will be, since the best, and brightest astronomers may not be able to actually strap themselves onto a pile of explosives for the trip to the moon or back.
VACUUM INDUSTRIES: On earth, an industrial vacuum is a costly thing to maintain, and in al honesty, it isn’t very vacuous. This forces the vacuum industry to work with a high overhead, and produce substandard products.
Some people have argued that vacuum industries could achieve a better vacuum by assembling their products on the trailing side of satellites. Most satellites, however, have a very small customer base and few resources. Another problem with satellite is that importing resources or exporting product is a costly business.
These are all problems with man-made satellites, but not such a problem with natural satellites, such as the moon. The moon could support a reasonable customer base. The moon has resources for producing electronics. The moon also has far more possible applications for the various electronic components that could be made.
The moon has a very, very tenuous atmosphere, at least during the night. However, I suspect that this is still a harder vacuum than industrial vacuums on earth, and even if it is not, mechanical vacuum forming processes would be more effective on the moon than on earth.
The trailing hemisphere of the moon is likely to host some form of vacuum industries. Near the poles, equipment for local use could be made with fairly low overhead due to the permanent solar energy.
Near the nearest and farthest points from earth, hubs for the production of product to be exported to other worlds might form, taking advantage of the lower escape velocity for shipping.
Along the equator in general, shipping facilities might crop up, but the largest is sure to be near the terminator, where the vacuum should be hardest, and a communication line to the earth could be assured.
ROVER TRANSPORT: Using some sort of transportation on the surface will be necessary. Wheeled vehicles should suffice for most places on the Maria, at least until roads can be made. In the highlands, other forms of transportation may prove necessary. Jumping devices have been suggested, but I have some doubts about that system.
MINING: Underground habitats are likely to be the norm on the moon, and obtaining resources will be difficult. I expect that tunnel digging, for both of these purposes is likely to be extensive. In the highlands, with thick regolith, tunneling will be easier, impact bodies are more numerous and the bedrock is more varied. I suspect that much of our efforts will focus here, in an effort to obtain metallic and carbonaceous meteorites, if for nothing else. Since the surface of the highlands is not particularly amenable to transportation, many abandoned shafts may be filled in with habitats, and subways.
SATELLITE CONSTRUCTION: The lunar surface has everything necessary for the construction of satellites; iron, silicon, refractories for aero braking shields, a hard vacuum for constructing electronic components, and hard radiation for radiation hardening.
The moon also has one sixth the gravity of the earth, so that launching a particular mass from the moon should be cheaper than launching the same mass from earth. A shot from the moon down to the earth takes very little power. Sadly, the moon doesn’t have a lot of volatiles. Fueling these satellites for their trip to earth could be a challenge. Thankfully, once in earth orbit, filling up the station keeping attitude jets is simple enough.
This could be a very lucrative business if only there was a way to launch the satellites off the moon without using volatiles such as hydrogen, which is in extremely short supply.
BALLISTIC SHIPPING: On the moon, no roads, rails, subways, or other paths have yet been formed. There is no liquid for shipping over, and no gasses for flying though. Transportation has traditionally been by foot, off road vehicles, or ballistic trajectories.
Rockets are considered ideal for ballistic travel, since they possess the capability of altering their course while in flight. Technically, this ability makes their paths not quite ballistic. However, since they do not posses enough fuel for constant course changing, most of their path is ballistic in nature.
Most of the fuel expended in rocket travel is during takeoff, and landing. In fact, NASA’s preference for exploring Mars stems mainly from the fact that they can reduce fuel expenditure for landing by such processes as aero braking, and parachutes. These practices require an atmosphere to slow down in.
On the moon, only the tiniest bit of fuel can be conserved, by using air bags to cushion the impact. Thus, landing will be an expensive process for years to come. Takeoff from the moon may not always be so expensive though.
In the early days of flight, airplanes did not rely on their own propulsion to get started. They used catapults, and various other launching systems to achieve this speed. With a little building equipment, there is no reason some similar devices cannot be built on the moon to launch objects.
The transportation of smaller goods in this manner could quickly be achieved, allowing for a mail system that relies on throwing messages attached to rocks. For larger goods, air bags, and perhaps even retro rockets for slowing down before landing may be necessary.
Catapults and other mechanical projectile weapons may serve adequately for numerous purposes, but I do not think human transportation would be one of them. Even with retro rockets, air bags, hydraulic landing gear, and what not, humans generally shy away from getting inside anything that was once used to break down castle walls.
For humans, a magnetic mass driver may prove more psychologically acceptable. These devices also have the major benefit of being able to accelerate slowly. There is no theoretical upper limit to the size, or mass that such a device could be capable of launching, and these devices may even be used to send people back to earth, where small rockets for adjusting the entry corridor, heat shields, parachutes, and a floating capsule are all that would be needed for a safe landing.
On earth, using such a device would be nearly impossible, but on the moon, no atmosphere slows us down, less gravity holds us in place, and the cold temperatures achieved at night will improve the power of the magnetic fields. Such a device might even prove to be a useful way to use the moon as a stepping stone to Mars. It certainly has at least as much validity as wasting the precious lunar polar ice deposits to achieve the same goal.
1) The Case for Mars, by Robert Zubrin. Simon & Schuster, NY, NY, 1996. ISBN 0-684-83550-9
2) Moon Missions, by William F. Melberg. Plymouth Press, Plymouth, MI, 1997. ISBN 1-882663-12-8
3) Mining the Sky, by John S. Lewis. Perseus Books, Reading, Massachusetts. 1996. ISBN 0-201-32819-4
4) Out of the Silent Planet, by Clive Staples Lewis. ISBN 0-00-628165-6