Colonize the Moon
The moon has always been the object of our fascination. It has a gravitational pull that is only one-sixth of Earth’s, which means that it can never have an atmosphere to speak of. But even so, it is still a place where we could live. In the future, we may colonize the moon for many reasons. One reason is to establish a base for space exploration and research. Another reason is to mine resources like helium-3 – which can be used as fuel for nuclear fusion power plants on Earth – from lunar soil and send them back to Earth.
Various theories hypothesize how the moon formed, including the capture theory, the fission theory, and the twin formation theory. However, the soil samples from the surface of the moon, collected in 1969, did not support any of these theories. The composition of moon rocks contains earth rocks (iron, volatiles, and oxygen isotope ratios) and cosmic object rocks. This led to the development of the impact theory in 1975. According to the impact theory, a cosmic object crashed into the earth sending rocks from the crust into orbit. As these rocks cooled, gravity formed the moon. The impact would also explain why the earth’s axis is tilted at an angle.
The debate over a cold moon versus a hot moon was settled when we saw up close that the moon’s surface had ravines and molten rocks, proving the moon was hot at one point. The Late Heavy Bombardment theory set the timeframe for when life appeared on earth. All seven basins where the moon was struck contain rocks from 3.8 – 4 billion years ago. This suggests the earth was struck at the same time and that life began 3.5 billion years ago. There are rocks in the Imbrium-Procellarum terrain that are 4.5 billion years old, which is close to the age of the universe (4.57 billion years old). These rocks may not be the oldest though. We still need to sample rocks from the largest basin, called Aitken, at the South Pole. This could help determine how old the solar system is and how it came about.
Arrive on the moon by 2030 with a crew of 16 scientists and engineers. The base will be on the south side because this is where the deepest crater is and where ice crystals have been found. Initially, the colony will not be self-sustaining, and combustibles will have to be shipped five times a year. A sustainable and affordable human and robotic program on the moon should be implemented. To promote international and commercial participation, we must find a resource that can be mined for profit and be used to produce solar power for all energy needs. We should mine for solar wind volatiles (helium-3 isotopes). They are created by the sun’s fusion reaction, which turns hydrogen into helium. It is a stable isotope of helium with only one neutron instead of two. Volatiles are more abundant on the far side of the moon since the near side of the moon always faces the earth.
The moon has a simpler mineral composition than the earth because it consists of lower boiling point elements. The surface composition is O: 42%, Si: 21%, Fe: 13%, Ca: 8%, Al: 7%, and Mg: 6%.
98% of the moon is made of four minerals:
- Anorthite (CaAlSi2O8) is a common form of plagioclase feldspar. NaAlSi2O8 is another, and it contains no iron and is therefore light, which is why the astronauts mainly brought this back.
- Olivine: (Mg, Fe) 2SiO4 is green
- Pyroxene: FeSiO3 and CaFeSi2O6
- Ilmenite: FeTiO3 is dark and heavy. Composition: TiO2: 52 – 54%, FeO: 45%, Al2O3: 0.3 – 0.4%, MnO: 0.3 – 0.4%, Cr2O3: 0.2 – 0.4%, and MgO: 0.1 – 0.4%.
Other than mare basalts (cooled molten rocks), most rocks are breccias. They are formed by the shock wave of high-speed impact craters fusing material. As a result, many craters have small glass pools at the bottom. Later research showed that the anorthosite samples came from 600 miles below the moon’s surface from meteorite impacts. It proved the moon was a magma ocean at one point.
The surface has an inch of dust which can cause problems, followed by 30 feet of pulverized rock fragments that can be mined. After a few feet, it becomes tough as cement and must be broken up with explosives. Since mineral deposits are formed by the action of water, elements such as gold, silver, and platinum are unlikely to be present. They would not justify going there anyway. In 1994, ice crystals were discovered, in the bottom of a permanently shadowed crater near the south pole. The icy patches cover an estimated 15,400 square miles (the size of Maryland and Delaware combined). There was no evidence of water on the moon previously because there was no water vapor, sedimentary rocks, or hydrous minerals such as mica. Highlands cover 85% of the surface and almost all the far side. This area is rich in aluminum, which can be extracted, and closer craters can be searched for diamonds or coesite (SiO2).
Benefits and Feasibility
It is intriguing to discover what we can accomplish as a human race and how the universe began. The technology is there, but there are not yet adequate nuclear fusion reactors that can handle even trace amounts of helium-3.10 In addition, mining enough He-3 to make it worthwhile is a daunting task. There is only 20 ppb He-3 in the regolith, which means we need to mine a 0.75-mile area, 9 feet deep. This yields 220 pounds of He-3, worth $141 million. The mining of 2*109 tons per year of regolith will not disturb the moon’s orbit because the moon weighs much less than the earth (73*1018 tons vs 5.976*1021 tons).
Qualifications & Schedule
- Extract oxygen
- Oxygen is found in 45% of the regolith.
- It produces water, vital to sustain life.
- Is stored as rocket fuel. 85% of rocket fuel is oxygen.
- Extraction occurs by fluffing up moon dust (ilmenite), reacting it with hydrogen, and adding heat or ionizing the hydrogen. The dirt then acts like a fluid, which contributes to the production of water.
- Many processes require high temperatures and thus large amounts of energy.
- Titanium and more oxygen can be extracted by chlorine or fluorine reactions.
- Waste products Si, Fe, and TiO2 are used for solar cells.
- Fuel cells use H2 and O2.
- Life-support uses N2O2, H2O, and CO2.
- Propulsion uses H2, O2, and He-4,
- Hydrogen cycle: H2 + FeTiO3 <-> Fe + TiO2 + H2O -> H2 + ½ O2 (900 °C).
- Carbon monoxide cycle: FeTiO3 + CO <-> Fe + TiO2 + CO2.
- Methane cycle:
- FeTiO3 + CH4 <-> Fe + TiO2 + CO + 2H2
- 2CO + 6H2 <-> 2CH4 + 2H2O
- 2H2O <-> 2H2 + O2
- Williams’s reduction reaction: 79’ FeTiO3 + H2 <-> Fe + TiO2 + H2O2
- Build a camp in the largest crater
- Craters, commonly called mascons, have higher gravity due to their concentrated mass. The increased gravity will help keep the machines on the ground.
- To build the camp, we need an efficient way to extract iron from dirt to use for building materials and electrical cables. The mare has up to 20% weight iron, but we need a way to find where the iron is concentrated, and then use large magnets to separate the iron.
- The structure of the base camp will be constructed with a bulldozer brought from earth, which can also produce the bricks used for the buildings. The bulldozer will excavate roads, the power systems area, the habitat and crew workstation, and the volatile refining area. Later, it will create a launch and landing area that is a safe distance from the camp to maintain dust control.
- Assemble the rover brought from earth.
- The rover is powered by solar panels on top, which can rotate to achieve optimum solar flux. The rover will have sufficient mass to remain on the surface and give it traction. Due to its heavier mass, its speed will be slow compared to on earth (P = mv).
- Its task is to scoop up the moon dust and process it for helium-3 and other elements or vacuum the dust into an area that can be stored and processed later.
- It grates the surface smooth and heats it to form silicon solar cells. Solar panels will be on an incline, with incident solar radiation normal to them. The electricity generated is sent to a transducer on a pole 100 feet in the air attached to the base. The environment is an ultra-high vacuum, so it is easy to create thin film solar panels, and the necessary Si, Fe, TiO2, Ca, and Al are already present.
- The earth’s atmosphere does not obstruct solar energy from reaching the solar panels, and eight times more sunlight reaches them. However, the efficiency of lunar panels is 0.266% (low-end) compared to 20% for satellite panels. The lunar panels are 1/12th as efficient as satellite panels, so the panels must cover 15.3% of the lunar surface to justify this approach.
- Theoretically, if the lunar panels were doped with GaAs, their efficiency increases by a factor of 3.
- Produce stainless steel
- Heat-treated type 420, which can be used for future machines, rockets, and building materials. Composition: Fe: 86.65%, Cr: 13%, C: 0.35%.
- Set up radar equipment
- To decide where the best place to mine for volatiles and set up satellite dishes.
- Make shielding for habitat
- A few feet of regolith over the buildings
- Weld and produce glass fibers for fiber optics
- Advanced or retreat mining
- The most preferred for the quick return on investment.
- Most of the energy will be used to bust the rock up and classify it.
- Also, a combination of surface and underground mining will be used.
- Other options are drill and blast, in-situ recovery with solutions to heap leach out metals from the ore in the ground, or open-cut.
- A crusher with a jaw is used to break up the material.
- Other options are gyratory, cone, and ball/rod mill.
- For the sorter, we can use grizzles, screens, cyclones, flotation, settling velocity, or shaker table.
- A mining bulldozer can switch from a scraper, rake, and plow.
- Aluminum will be mined along with other ores.
- The new Saturn VI must cost $3,000/kg and have a payload of 104 kg (the current Saturn V costs $57,000/kg and has a payload of 105 kg).
- 75% of the costs incurred in the first 30 years
- Total cost: $19.95B
- Capital costs (setup costs of the plant): $1.098B/1,000MW plant ($1,098/kW)
- Saturn VI capability: $5B
- Basic support: $1.5B
- Flight: $1.5B
- Fuel: $1000/kg
- Demonstration plant: $5B
- Development planning: $1B
- He-3 plant: $1.5B
- Fusion power plant: $6B
- Assume $15B capital available.
- Revenue: $800B/kW-h
- 15 miner-processor He-3: $585M/yr
- Fusion: $1B net
- Gross: 10 years from arrival and 15th plant: $1.1B
- Breakeven: 12-years
- Breakeven: $140 M/100 kg He-3
The downside to fusion or He-3 is it takes 18 years to build the first operating 100 kg He-3 plant or 1,000 MW fusion plant. The upside is it is clean (non-radioactive) energy. The project must provide near-term returns on investment and support expansion through internal cash flows. The production of radioisotopes for medical (cancer) treatment on earth will help justify the costs. Equipment and buildings have a limited lifetime due to particle and radiation damage. The equipment will remain operational while astronauts work on it, and 90% of manufacturing and machine operations will be carried out from the earth.
To justify this mission, we must supply most of the world’s energy. This breaks down to 20 TW per year by 2050 and 1,000 TW per year by 2070. Once we have 13,000 MW for the moon base, we will make more solar panels on the flat surfaces of the moon and send 20 – 30 TW to 12 receiving stations on earth via radio waves. This must be an international effort and would be a launch platform for Mars. NASA’s initial plan was to go to Mercury, and they had planned missions. They were not interested in going to the moon and most scientists agreed the moon was not worth the scientific benefit. Everything changed when President John F. Kennedy gave his famous 1961 speech, which brought us to the moon. Why did we not want to spend only 0.5% of our GDP on NASA after the Apollo flights? There were crashes, but mainly scientists withdrew from the debate when they noticed that advanced scientific missions did not follow the Apollo missions.
1. D. Mackenzie. The Big Splat: Or How Our Moon Came to Be. Hoboken, New Jersey. John Wiley & Sons. 2003.
2. D. Nardo. The Moon. Farmington Hills, Michigan: KidHaven Press. 2003.
6. H. H. Schmitt. “Mining the Moon”, Popular Mechanics. October 2004.
8. M. Smith. “Moon Reports: Moon Wars”.
9. Fusion Technology Institute: NEEP533 Course Notes (Spring 2004) Resources from Space. The University of Wisconsin-Madison. May 7, 2004.