Colonization of the Moon

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1986 artist concept

The colonization of the Moon is the proposed establishment of permanent human communities or robot industries^[1] on the Moon.

Recent indication that water might be present in noteworthy quantities at the lunar poles has renewed interest in the Moon. Polar colonies could also avoid the problem of long lunar nights – about 354 hours,^[2] a little more than two weeks – and take advantage of the sun continuously, at least during the local summer (there is no data for the winter yet).^[3]

Permanent human habitation on a planetary body other than the Earth is one of science fiction's most prevalent themes. As technology has advanced, and concerns about the future of humanity on Earth have increased, the argument that space colonization is an achievable and worthwhile goal has gained momentum.^[4][5] Because of its proximity to Earth, the Moon has been seen as the most obvious natural expansion after Earth.

Proposals

Concept art from NASA showing astronauts entering a lunar outpost

The notion of siting a colony on the Moon originated before the Space Age. In 1638 Bishop John Wilkins wrote A Discourse Concerning a New World and Another Planet, in which he predicted a human colony on the Moon.^[6] Konstantin Tsiolkovsky (1857–1935), among others, also suggested such a step.^[7] From the 1950s onwards, a number of concepts and designs have been suggested by scientists, engineers and others.

In 1954, science-fiction author Arthur C. Clarke proposed a lunar base of inflatable modules covered in lunar dust for insulation.^[8] A spaceship, assembled in low Earth orbit, would launch to the Moon, and astronauts would set up the igloo-like modules and an inflatable radio mast. Subsequent steps would include the establishment of a larger, permanent dome; an algae-based air purifier; a nuclear reactor for the provision of power; and electromagnetic cannons to launch cargo and fuel to interplanetary vessels in space.

In 1959, John S. Rinehart suggested that the safest design would be a structure that could "[float] in a stationary ocean of dust", since there were, at the time this concept was outlined, theories that there could be mile-deep dust oceans on the Moon.^[9] The proposed design consisted of a half-cylinder with half-domes at both ends, with a micrometeoroid shield placed above the base.

Project Horizon

Project Horizon was a 1959 study regarding the United States Army's plan to establish a fort on the Moon by 1967.^[10] Heinz-Hermann Koelle, a German rocket engineer of the Army Ballistic Missile Agency (ABMA) led the Project Horizon study. The first landing would be carried out by two "soldier-astronauts" in 1965 and more construction workers would soon follow. Through numerous launches (61 Saturn I and 88 Saturn II), 245 tons of cargo would be transported to the outpost by 1966.

Lunex Project

Lunex Project was a US Air Force plan for a manned lunar landing prior to the Apollo Program in 1961. It envisaged a 21-airman underground Air Force base on the Moon by 1968 at a total cost of $7.5 billion.

Sub-surface base

In 1962, John DeNike and Stanley Zahn published their idea of a sub-surface base located at the Sea of Tranquility.^[8] This base would house a crew of 21, in modules placed four meters below the surface, which was believed to provide radiation shielding on par with Earth's atmosphere. DeNike and Zahn favored nuclear reactors for energy production, because they were more efficient than solar panels, and would also overcome the problems with the long Lunar nights. For the life support system, an algae-based gas exchanger was proposed.

Recent proposals

As of 2006, Japan planned to have a Moon base in 2030.^[11]

As of 2007, Russia planned to have a Moon base in 2027–2032.^[12]

In 2007 Jim Burke of the International Space University in France said people should plan to preserve humanity's culture in the event of a civilization-stopping asteroid impact with Earth. A
Lunar Noah's Ark was proposed.^[13] Subsequent planning may be taken up by the International Lunar Exploration Working Group (ILEWG).^[14][15][16]

In a January 2012 speech Newt Gingrich, Republican candidate for President, proposed a plan to build a U.S. moon colony by the year 2020.^[17]

Moon exploration

Exploration of the Lunar surface by spacecraft began in 1959 with the Soviet Union's Luna program. Luna 1 missed the Moon, but Luna 2 made a hard landing (impact) into its surface, and became the first artificial object on an extraterrestrial body. The same year, the Luna 3 mission radioed photographs to Earth of the Moon's hitherto unseen far side, marking the beginning of a decade-long series of unmanned Lunar explorations.

Responding to the Soviet program of space exploration, US President John F. Kennedy in 1961 told the U.S. Congress on May 25: "I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the Earth." The same year the Soviet leadership made some of its first public pronouncements about landing a man on the Moon and establishing a Lunar base.

Manned exploration of the lunar surface began in 1968 when the Apollo 8 spacecraft orbited the Moon with three astronauts on board. This was mankind's first direct view of the far side. The following year, the Apollo 11 Lunar module landed two astronauts on the Moon, proving the ability of humans to travel to the Moon, perform scientific research work there, and bring back sample materials.

Additional missions to the Moon continued this exploration phase. In 1969 the Apollo 12 mission landed next to the Surveyor 3 spacecraft, demonstrating precision landing capability. The use of a manned vehicle on the Moon's surface was demonstrated in 1971 with the Lunar Rover during Apollo 15. Apollo 16 made the first landing within the rugged Lunar highlands. However, interest in further exploration of the Moon was beginning to wane among the American public. In 1972 Apollo 17 was the final Apollo Lunar mission, and further planned missions were scrapped at the directive of President Nixon. Instead, focus was turned to the Space Shuttle and manned missions in near Earth orbit.

The Soviet manned lunar programs failed to send a manned mission to the Moon. However, in 1966 Luna 9 was the first probe to achieve a soft landing and return close-up shots of the Lunar surface. Luna 16 in 1970 returned the first Soviet Lunar soil samples, while in 1970 and 1973 during the Lunokhod program two robotic rovers landed on the Moon. Lunokhod 1 explored the Lunar surface for 322 days, and Lunokhod 2 operated on the Moon about four months only but covered a third more distance. 1974 saw the end of the Soviet Moonshot, two years after the last American manned landing. Besides the manned landings, an abandoned Soviet moon program included building the moonbase "Zvezda", which was the first detailed project with developed mockups of expedition vehicles^[18] and surface modules.^[19]

In the decades following, interest in exploring the Moon faded considerably, and only a few dedicated enthusiasts supported a return. However, evidence of Lunar ice at the poles gathered by NASA's Clementine (1994) and Lunar Prospector (1998) missions rekindled some discussion,^[20][21] as did the potential growth of a Chinese space program that contemplated its own mission to the Moon.^[22] Subsequent research suggested that there was far less ice present (if any) than had originally been thought, but that there may still be some usable deposits of hydrogen in other forms.^[23] However, in September 2009, the Chandrayaan probe, carrying an ISRO instrument, discovered that the Lunar regolith contains 0.1% water by weight, overturning theories that had stood for 40 years.^[24]

In 2004, U.S. President George W. Bush called for a plan to return manned missions to the Moon by 2020 (since cancelled – see Constellation program). Propelled by this new initiative, NASA issued a new long-range plan that includes building a base on the Moon as a staging point to Mars. This plan envisions a Lunar outpost at one of the moon's poles by 2024 which, if well-sited, might be able to continually harness solar power; at the poles, temperature changes over the course of a Lunar day are also less extreme,^[25] and reserves of water and useful minerals may be found nearby.^[25] In addition, the European Space Agency has a plan for a permanently manned Lunar base by 2025.^[26][27] Russia has also announced similar plans to send a man to the moon by 2025 and establish a permanent base there several years later.^[5]

A Chinese space scientist has said that the People's Republic of China could be capable of landing a human on the Moon by 2022 (see Chinese Lunar Exploration Program),^[28] and Japan and India also have plans for a Lunar base by 2030.^[29] Neither of these plans involves permanent residents on the Moon. Instead they call for sortie missions, in some cases followed by extended expeditions to the Lunar base by rotating crew members, as is currently done for the International Space Station.
NASA’s LCROSS/LRO mission had been scheduled to launch in October 2008.^[30] The launch was delayed until 18 June 2009,^[31] resulting in LCROSS's impact with the Moon at 11:30 UT on 9 October 2009.^[32][33] The purpose is preparing for future Lunar exploration.

Water discovered on Moon

On September 24, 2009 NASA announced the discovery of water on the Moon. The discovery was made by three instruments on board Chandrayaan-1. These were the ISRO's Moon Impact Probe (MIP), the Moon Mineralogy Mapper (M3) and Mini-Sar, belonging to NASA.^[34]

On November 13, 2009 NASA announced that the LCROSS mission had discovered large quantities of water ice on the Moon around the LCROSS impact site at Cabeus. Robert Zubrin, president of the Mars Society, relativized the term 'large': "The 30 m crater ejected by the probe contained 10 million kilograms of regolith. Within this ejecta, an estimated 100 kg of water was detected. That represents a proportion of ten parts per million, which is a lower water concentration than that found in the soil of the driest deserts of the Earth. In contrast, we have found continent sized regions on Mars, which are 600,000 parts per million, or 60% water by weight."^[35] Although the Moon is very dry on the whole, the spot where the LCROSS impacter hit was chosen for a high concentration of water ice. Dr. Zubrin's computations are not a sound basis for estimating the percentage of water in the regolith at that site. Researchers with expertise in that area estimated that the regolith at the impact site contained 5.6 ± 2.9% water ice, and also noted the presence of other volatile substances. Hydrocarbons, material containing sulfur, carbon dioxide, carbon monoxide, methane and ammonia were present.^[36]

In March 2010, NASA reported that the findings of its mini-SAR radar aboard Chandrayaan-1 were consistent with ice deposits at the Moon's north pole. It is estimated there is at least 600 million tons of ice at the north pole in sheets of relatively pure ice at least a couple of meters thick.^[37]

In March 2014, researchers who had previously published reports on possible abundance of water on the Moon, reported new findings that refined their predictions substantially lower.^[38]

Advantages and disadvantages

Placing a colony on a natural body would provide an ample source of material for construction and other uses in space, including shielding from cosmic radiation. The energy required to send objects from the Moon to space is much less than from Earth to space. This could allow the Moon to serve as a source of construction materials within cis-lunar space. Rockets launched from the Moon would require less locally produced propellant than rockets launched from Earth. Some proposals include using electric acceleration devices (mass drivers) to propel objects off the Moon without building rockets. Others have proposed momentum exchange tethers (see below). Furthermore, the Moon does have some gravity, which experience to date indicates may be vital for fetal development and long-term human health.^[39][40] Whether the Moon's gravity (roughly one sixth of Earth's) is adequate for this purpose, however, is uncertain.

In addition, the Moon is the closest large body in the Solar System to Earth. While some Earth-crosser asteroids occasionally pass closer, the Moon's distance is consistently within a small range close to 384,400 km. This proximity has several benefits:

• A lunar base could be a site for launching rockets with locally-manufactured fuel to distant planets such as Mars. Launching rockets from the Moon would be easier than from Earth because the Moon's gravity is lower, requiring a lower escape velocity. A lower escape velocity would require less propellant, but there is no guarantee that less propellant would cost less money than that required to launch from Earth.
• The energy required to send objects from Earth to the Moon is lower than for most other bodies.
• Transit time is short. The Apollo astronauts made the trip in three days and future technologies could improve on this time.
• The short transit time would also allow emergency supplies to quickly reach a Moon colony from Earth, or allow a human crew to evacuate relatively quickly from the Moon to Earth in case of emergency. This could be an important consideration when establishing the first human colony.
• If the Moon were colonized then it could be tested if humans can survive in low gravity. Those results could be utilized for a viable Mars colony as well.
• The round trip communication delay to Earth is less than three seconds, allowing near-normal voice and video conversation, and allowing some kinds of remote control of machines from Earth that are not possible for any other celestial body. The delay for other Solar System bodies is minutes or hours; for example, round trip communication time between Earth and Mars ranges from about eight to forty minutes. This, again, could be particularly valuable in an early colony, where life-threatening problems requiring Earth's assistance could occur.
• On the Lunar near side, the Earth appears large and is always visible as an object 60 times brighter than the Moon appears from Earth, unlike more distant locations where the Earth would be seen merely as a star-like object, much as the planets appear from Earth. As a result, a Lunar colony might feel less remote to humans living there.
• A Lunar base would provide an excellent site for any kind of observatory.^[4] In the near-vacuum of the Moon's atmosphere, there is practically no atmospheric diffraction. Observations could be made continuously, provided that during the lunar day an optical telescope would be shaded from the Sun and from surrounding glare, and that it would not be pointed too close to the Sun or to the horizon. It would be possible to maintain constant observations on a specific target with a few such observatories at different longitudes. The Moon's geological inactivity and its infrastructural remoteness bring about an unusual mechanical calmness, which would be advantageous particularly regarding the erection of interferometric telescopes, even at relatively high frequencies such as visible light.^[41] NASA scientists have done developmental work toward manufacturing telescope mirrors using lunar material.^[42] Building observatory facilities on the Moon from lunar materials allows many of the benefits of space based facilities without the need to launch these into space.
• A farm at the Lunar North Pole could provide eight hours of sunlight per day during the local summer by rotating crops in and out of the sunlight which is continuous for the entire summer. A beneficial temperature, radiation protection, insects for pollination, and all other plant needs could be artificially provided during the local summer for a cost. One estimate suggested a 0.5 hectare space farm could feed 100 people.^[43]
• With fewer rockets launched from Earth, there would be less contribution to global warming through the burning of rocket fuel.

There are several disadvantages to the Moon as a colony site:

• The long lunar night would impede reliance on solar power and require a colony to be designed that could withstand large temperature extremes. An exception to this restriction are the so-called "peaks of eternal light" located at the Lunar north pole that are constantly bathed in sunlight. The rim of Shackleton Crater, towards the Lunar south pole, also has a near-constant solar illumination. Other areas near the poles that get light most of the time could be linked in a power grid.
• The Moon is highly depleted in volatile elements, such as nitrogen and hydrogen. Carbon, which forms volatile oxides, is also depleted. A number of robot probes including Lunar Prospector gathered evidence of hydrogen generally in the Moon's crust consistent with what would be expected from solar wind, and higher concentrations near the poles.^[44] There had been some disagreement whether the hydrogen must necessarily be in the form of water. The mission of the Lunar Crater Observation and Sensing Satellite (LCROSS) proved in 2009 that there is water on the Moon.^[45] This water exists in ice form perhaps mixed in small crystals in the regolith in a colder landscape than people have ever mined. Other volatiles containing carbon and nitrogen were found in the same cold trap as ice.^[36] If no sufficient means is found for recovering these volatiles on the Moon, they would need to be imported from some other source to support life and industrial processes. Volatiles would need to be stringently recycled. This would limit the colony's rate of growth and keep it dependent on imports. The transportation cost of importing volatiles from Earth could be reduced by constructing the upper stage of supply ships using materials high in volatiles, such as carbon fiber and plastics. The 2006 announcement by the Keck Observatory that the binary Trojan asteroid 617 Patroclus,^[46] and possibly large numbers of other Trojan objects in Jupiter's orbit, are likely composed of water ice, with a layer of dust, and the hypothesized large amounts of water ice on the closer, main-belt asteroid 1 Ceres, suggest that importing volatiles from this region via the Interplanetary Transport Network may be practical in the not-so-distant future. However, these possibilities are dependent on complicated and expensive resource utilization from the mid to outer Solar System, which is not likely to become available to a Moon colony for a significant period of time.
• It is uncertain whether the low (one-sixth g) gravity on the Moon is strong enough to prevent detrimental effects to human health in the long term. Exposure to weightlessness over month-long periods has been demonstrated to cause deterioration of physiological systems, such as loss of bone and muscle mass and a depressed immune system. Similar effects could occur in a low-gravity environment, although virtually all research into the health effects of low gravity has been limited to zero gravity.
• The lack of a substantial atmosphere for insulation results in temperature extremes and makes the Moon's surface conditions somewhat like a deep space vacuum. It also leaves the Lunar surface exposed to half as much radiation as in interplanetary space (with the other half blocked by the moon itself underneath the colony), raising the issues of the health threat from cosmic rays and the risk of proton exposure from the solar wind, especially since two-thirds^{[citation needed]} of the Moon's orbit is outside the protection of the Earth's magnetosphere. Lunar rubble can protect living quarters from cosmic rays.^[47] Shielding against solar flares during expeditions outside is more problematic.
• When the moon passes through the magnetotail of the earth, the plasma sheet whips across its surface. Electrons crash into the moon and are released again by UV photons on the day side but build up voltages on the dark side.^[48] This causes a negative charge build up from −200 V to −1000 V. See Magnetic field of the Moon.
• The lack of an atmosphere increases the chances of the colony being hit by meteor. Even small pebbles and dust (micrometeoroids) have the potential to damage or destroy insufficiently protected structures.
• Moon dust is an extremely abrasive glassy substance formed by micrometeorites and unrounded due to the lack of weathering. It sticks to everything and can damage equipment, and it may be toxic.^[49]
• Growing crops on the Moon faces many difficult challenges due to the long lunar night (354 hours), extreme variation in surface temperature, exposure to solar flares, nitrogen-poor soil, and lack of insects for pollination. Due to the lack of any atmosphere on the Moon, plants would need to be grown in sealed chambers, though experiments have shown that plants can thrive at pressures much lower than those on Earth.^[50] The use of electric lighting to compensate for the 354-hour night might be difficult: a single acre of plants on Earth enjoys a peak 4 megawatts of sunlight power at noon. Experiments conducted by the Soviet space program in the 1970s suggest it is possible to grow conventional crops with the 354-hour light, 354-hour dark cycle.^[51] A variety of concepts for lunar agriculture have been proposed,^[52] including the use of minimal artificial light to maintain plants during the night and the use of fast growing crops that might be started as seedlings with artificial light and be harvestable at the end of one Lunar day.^[53]
• One of the less obvious difficulties lies not with the Moon itself but rather with the political and national interests of the nations engaged in colonization. Assuming that colonization efforts were able to overcome the difficulties outlined above – there would likely be issues regarding the rights of nations and their colonies to exploit resources on the lunar surface, to stake territorial claims and other issues of sovereignty which would have to be agreed upon before one or more nations established a permanent presence on the moon. The ongoing negotiations and debate regarding the Antarctic is a good case study for prospective lunar colonization efforts in that it highlights the numerous pitfalls of developing/inhabiting a location that is subject to the claims of multiple sovereign nations.

Locations

Three criteria that a Lunar outpost should meet are:

• good conditions for transport operations;
• a great number of different types of natural objects and features on the Moon of scientific interest; and
• natural resources, such as oxygen. The abundance of certain minerals, such as iron oxide, varies dramatically over the Lunar surface.^[54]

While a colony might be located anywhere, potential locations for a Lunar colony fall into three broad categories.

Polar regions

There are two reasons why the north pole and south pole of the moon might be attractive locations for a human colony. First, there is evidence that water may be present in some continuously shaded areas near the poles.^[55] Second, the Moon's axis of rotation is sufficiently close to being perpendicular to the ecliptic plane that the radius of the Moon's polar circles is less than 50 km. Power collection stations could therefore be plausibly located so that at least one is exposed to sunlight at all times, thus making it possible to power polar colonies almost exclusively with solar energy. Moreover, due to the Moon's uneven surface some sites have nearly continuous sunlight. For example, Malapert mountain, located near the Shackleton crater at the Lunar south pole, offers several advantages as a site:

• It is exposed to the sun most of the time (see Peak of Eternal Light for further discussion); two closely spaced arrays of solar panels would receive nearly continuous power.^[56]
• Its proximity to Shackleton Crater (116 km, or 69.8 mi) means that it could provide power and communications to the crater. This crater is potentially valuable for astronomical observation. An infrared instrument would benefit from the very cold temperatures. A radio telescope would benefit from being shielded from Earth's broad spectrum radio interference.^[56]
• The nearby Shoemaker and other craters are in constant deep shadow, and might contain valuable concentrations of hydrogen and other volatiles.^[56]
• At around 5,000 meters (16,000 feet) elevation, it offers line of sight communications over a large area of the moon, as well as to Earth.^[56]
• The South Pole-Aitken basin is located at the Lunar south pole. This is the second largest known impact basin in the Solar System, as well as the oldest and biggest impact feature on the Moon,^[57] and should provide geologists access to deeper layers of the Moon's crust.

NASA chose to use a south-polar site for the Lunar outpost reference design in the Exploration Systems Architecture Study chapter on Lunar Architecture.^[57]

At the north pole, the rim of Peary Crater has been proposed as a favorable location for a base.^[58] Examination of images from the Clementine mission appear to show that parts of the crater rim are permanently illuminated by sunlight (except during Lunar eclipses).^[58] As a result, the temperature conditions are expected to remain very stable at this location, averaging −50 °C (−58 °F).^[58] This is comparable to winter conditions in Earth's Poles of Cold in Siberia and Antarctica. The interior of Peary Crater may also harbor hydrogen deposits.^[58]

A 1994^[59] bistatic radar experiment performed during the Clementine mission suggested the presence of water ice around the south pole.^[20][60] The Lunar Prospector spacecraft reported enhanced hydrogen abundances at the south pole and even more at the north pole, in 2008.^[61] On the other hand, results reported using the Arecibo radio telescope have been interpreted by some to indicate that the anomalous Clementine radar signatures are not indicative of ice, but surface roughness.^[62] This interpretation, however, is not universally agreed upon.^[63]

A potential limitation of the polar regions is that the inflow of solar wind can create an electrical charge on the leeward side of crater rims. The resulting voltage difference can affect electrical equipment, change surface chemistry, erode surfaces and levitate Lunar dust.^[64]

Equatorial regions

The Lunar equatorial regions are likely to have higher concentrations of helium-3 (rare on Earth but much sought after for use in nuclear fusion research) because the solar wind has a higher angle of incidence.^[65] They also enjoy an advantage in extra-Lunar traffic: The rotation advantage for launching material is slight due to the Moon's slow rotation, but the corresponding orbit coincides with the ecliptic, nearly coincides with the Lunar orbit around Earth, and nearly coincides with the equatorial plane of Earth.

Several probes have landed in the Oceanus Procellarum area. There are many areas and features that could be subject to long-term study, such as the Reiner Gamma anomaly and the dark-floored Grimaldi crater.

Far side

The Lunar far side lacks direct communication with Earth, though a communication satellite at the L₂ Lagrangian point, or a network of orbiting satellites, could enable communication between the far side of the Moon and Earth.^[66] The far side is also a good location for a large radio telescope because it is well shielded from the Earth.^[67] Due to the lack of atmosphere, the location is also suitable for an array of optical telescopes, similar to the Very Large Telescope in Chile.^[68] To date, there has been no ground exploration of the far side.

Scientists have estimated that the highest concentrations of helium-3 will be found in the maria on the far side, as well as near side areas containing concentrations of the titanium-based mineral ilmenite. On the near side the Earth and its magnetic field partially shields the surface from the solar wind during each orbit. But the far side is fully exposed, and thus should receive a somewhat greater proportion of the ion stream.^[69]

Lunar lava tubes

Lunar lava tubes are a potential location for constructing a Lunar base. Any intact lava tube on the moon could serve as a shelter from the severe environment of the Lunar surface, with its frequent meteorite impacts, high-energy ultra-violet radiation and energetic particles, and extreme diurnal temperature variations. Lava tubes provide ideal positions for shelter because of their access to nearby resources. They also have proven themselves as a reliable structure, having withstood the test of time for billions of years.

An underground colony would escape the extreme of temperature on the Moon's surface. The average temperature on the surface of the moon is about −5 °C. The day period (about 354 hours) has an average temperature of about 107 °C (225 °F), although it can rise as high as 123 °C (253 °F). The night period (also 354 hours) has an average temperature of about −153 °C (−243 °F).^[70] Underground, both periods would be around −23 °C (−9 °F), and humans could install ordinary air conditioners.^[71]

One such lava tube was discovered in early 2009.^[72]

Craters

The central peaks of large lunar craters may contain material that rose from as far 19 kilometers beneath the surface when the peaks formed by rebound of the compressed rock under the crater. Material moved from the interior of craters is piled in their rims.^[73] These and other processes make possibly novel concentrations of minerals accessible to future prospectors from lunar colonies.

Structure

Habitat

There have been numerous proposals regarding habitat modules. The designs have evolved throughout the years as mankind's knowledge about the Moon has grown, and as the technological possibilities have changed. The proposed habitats range from the actual spacecraft landers or their used fuel tanks, to inflatable modules of various shapes. Early on, some hazards of the Lunar environment such as sharp temperature shifts, lack of atmosphere or magnetic field (which means higher levels of radiation and micrometeoroids) and long nights, were recognized and taken into consideration.

Underground colonies

Some suggest building the Lunar colony underground, which would give protection from radiation and micrometeoroids. This would also greatly reduce the risk of air leakage, as the colony would be fully sealed from the outside except for a few exits to the surface.

The construction of an underground base would probably be more complex; one of the first machines from Earth might be a remote-controlled excavating machine. Once created, some sort of hardening would be necessary to avoid collapse, possibly a spray-on concrete-like substance made from available materials.^[74] A more porous insulating material also made in-situ could then be applied. Rowley & Neudecker have suggested "melt-as-you-go" machines that would leave glassy internal surfaces.^[75] Mining methods such as the room and pillar might also be used. Inflatable self-sealing fabric habitats might then be put in place to retain air. Eventually an underground city can be constructed. Farms set up underground would need artificial sunlight. As an alternative to excavating, a lava tube could be covered and insulated, thus solving the problem of radiation exposure.

Surface colonies

Variant for habitat creation on the surface or over lava tube

A NASA model of a proposed inflatable module

A possibly easier solution would be to build the Lunar base on the surface, and cover the modules with Lunar soil. The Lunar regolith is composed of a unique blend of silica and iron-containing compounds that may be fused into a glass-like solid using microwave energy.^[76] Blacic has studied the mechanical properties of lunar glass and has shown that it is a promising material for making rigid structures, if coated with metal to keep moisture out.^[77] This may allow for the use of "Lunar bricks" in structural designs, or the vitrification of loose dirt to form a hard, ceramic crust.

A Lunar base built on the surface would need to be protected by improved radiation and micrometeoroid shielding. Building the Lunar base inside a deep crater would provide at least partial shielding against radiation and micrometeoroids. Artificial magnetic fields have been proposed^[78][79] as a means to provide radiation shielding for long range deep space manned missions, and it might be possible to use similar technology on a Lunar colony. Some regions on the Moon possess strong local magnetic fields that might partially mitigate exposure to charged solar and galactic particles.^[80]

In a turn from the usual engineer-designed lunar habitats, London-based Foster + Partners architectural firm proposed a building construction 3D-printer technology in January 2013 that would use Lunar regolith raw materials to produce Lunar building structures while using enclosed inflatable habitats for housing the human occupants inside the hard-shell Lunar structures. Overall, these habitats would require only ten percent of the structure mass to be transported from Earth, while using local Lunar materials for the other 90 percent of the structure mass.^[81] "Printed" Lunar soil will provide both "radiation and temperature insulation. Inside, a lightweight pressurized inflatable with the same dome shape will be the living environment for the first human Moon settlers."^[81] The building technology will included mixing Lunar material with magnesium oxide. which will turn the "moonstuff into a pulp that can be sprayed to form the block" when a binding salt is applied that "converts [this] material into a stone-like solid."^[81] Terrestrial versions of this 3D-printing building technology are already printing 2 metres (6 ft 7 in) of building material per hour with the next-generation printers capable of 3.5 metres (11 ft) per hour, sufficient to complete a building in a week.^[81]

Moon Capital

In 2010, The Moon Capital Competition offered a prize for a design of a Lunar habitat intended to be an underground international commercial center capable of supporting a residential staff of 60 people and their families. The Moon Capital is intended to be self-sufficient with respect to food and other material required for life support. Prize money was provided primarily by the Boston Society of Architects, Google Lunar X Prize and The New England Council of the American Institute of Aeronautics and Astronautics.^[82]

3D printed structures

On January 31, 2013, the ESA working with an independent architectural firm, tested a 3D-printed structure that could be constructed of lunar regolith for use as a Moon base.^[83]

Energy

Nuclear power

A nuclear fission reactor might fulfill most of a Moon base's power requirements.^[84] With the help of fission reactors, one could overcome the difficulty of the 354 hour Lunar night. According to NASA, a nuclear fission power station could generate a steady 40 kilowatts, equivalent to the demand of about eight houses on Earth.^[84] An artist’s concept of such a station published by NASA envisages the reactor being buried below the Moon's surface to shield it from its surroundings; out from a tower-like generator part reaching above the surface over the reactor, radiators would extend into space to send away any heat energy that may be left over.^[85]

Radioisotope thermoelectric generators could be used as backup and emergency power sources for solar powered colonies.

Solar energy

Solar energy is a possible source of power for a Lunar base. Many of the raw materials needed for solar panel production can be extracted on site. However, the long Lunar night (354 hours) is a drawback for solar power on the Moon's surface. This might be solved by building several power plants, so that at least one of them is always in daylight. Another possibility would be to build such a power plant where there is constant or near-constant sunlight, such as at the Malapert mountain near the Lunar south pole, or on the rim of Peary crater near the north pole. A third possibility would be to leave the panels in orbit, and beam the power down as microwaves.

The solar energy converters need not be silicon solar panels. It may be more advantageous to use the larger temperature difference between sun and shade to run heat engine generators. Concentrated sunlight could also be relayed via mirrors and used in Stirling engines or solar trough generators, or it could be used directly for lighting, agriculture and process heat. The focused heat might also be employed in materials processing to extract various elements from Lunar surface materials.

Energy storage

In the early days, a combination of solar panels for 'day-time' operation and fuel cells for 'night-time' operation could be used.

Fuel cells on the Space Shuttle have operated reliably for up to 17 Earth days at a time. On the Moon, they would only be needed for 354 hours (14 3/4 days) – the length of the Lunar night. Fuel cells produce water directly as a waste product. Current fuel cell technology is more advanced than the Shuttle's cells – PEM (Proton Exchange Membrane) cells produce considerably less heat (though their waste heat would likely be useful during the Lunar night) and are lighter, not to mention the reduced mass of the smaller heat-dissipating radiators. This makes PEMs more economical to launch from Earth than the shuttle's cells. PEMs have not yet been proven in space.

Combining fuel cells with electrolysis would provide a 'perpetual' source of electricity – solar energy could be used to provide power during the Lunar day, and fuel cells at night. During the Lunar day, solar energy would also be used to electrolyze the water created in the fuel cells – although there would be small losses of gases that would have to be replaced.

Even if (and when) lunar colonies had provided themselves access to a near-continuous source of solar energy, they would still need to maintain fuel cells (or some other energy storage system) to sustain themselves during lunar eclipses and for emergencies.

Transport

Earth to Moon

Conventional rockets have been used for most Lunar exploration to date. The ESA's SMART-1 mission from 2003 to 2006 used conventional chemical rockets to reach orbit and Hall effect thrusters to arrive at the Moon in 13 months. NASA would have used chemical rockets on its Ares V booster and Lunar Surface Access Module, that were being developed for a planned return to the Moon around 2019, but this was cancelled. The construction workers, location finders, and other astronauts vital to building, would have been taken four at a time in NASA's Orion spacecraft.

Proposed concepts of Earth-Moon transportation are Space elevators and non-rotating Skyhooks.^[86][87]

On the surface

A Lunar rover being unloaded from a cargo spacecraft. Conceptual drawing

Lunar colonists will want the ability to transport cargo and people to and from modules and spacecraft, and to carry out scientific study of a larger area of the Lunar surface for long periods of time. Proposed concepts include a variety of vehicle designs, from small open rovers to large pressurized modules with lab equipment, and also a few flying or hopping vehicles.

Rovers could be useful if the terrain is not too steep or hilly. The only rovers to have operated on the surface of the Moon (as of 2008^[update]) are the three Apollo Lunar Roving Vehicles (LRV), developed by Boeing, and the two robotic Soviet Lunokhods. The LRV was an open rover for a crew of two, and a range of 92 km during one Lunar day. One NASA study resulted in the Mobile Lunar Laboratory concept, a manned pressurized rover for a crew of two, with a range of 396 km. The Soviet Union developed different rover concepts in the Lunokhod series and the L5 for possible use on future manned missions to the Moon or Mars. These rover designs were all pressurized for longer sorties.^[88]

If multiple bases were established on the Lunar surface, they could be linked together by permanent railway systems. Both conventional and magnetic levitation (Mag-Lev) systems have been proposed for the transport lines. Mag-Lev systems are particularly attractive as there is no atmosphere on the surface to slow down the train, so the vehicles could achieve velocities comparable to aircraft on the Earth. One significant difference with lunar trains, however, is that the cars would need to be individually sealed and possess their own life support systems.

For difficult areas, a flying vehicle may be more suitable. Bell Aerosystems proposed their design for the Lunar Flying Vehicle as part of a study for NASA. Bell also developed the Manned Flying System, a similar concept.

Surface to space

Launch technology

A Lunar base with a mass driver (the long structure that goes toward the horizon). NASA conceptual illustration

Experience so far indicates that launching human beings into space is much more expensive than launching cargo.

One way to get materials and products from the Moon to an interplanetary way station might be with a mass driver, a magnetically accelerated projectile launcher. Cargo would be picked up from orbit or an Earth-Moon Lagrangian point by a shuttle craft using ion propulsion, solar sails or other means and delivered to Earth orbit or other destinations such as near-Earth asteroids, Mars or other planets, perhaps using the Interplanetary Transport Network.

A Lunar space elevator could transport people, raw materials and products to and from an orbital station at Lagrangian points L₁ or L₂. Chemical rockets would take a payload from Earth to the L1 Lunar Lagrange location. From there a tether would slowly lower the payload to a soft landing on the lunar surface.

Other possibilities include a momentum exchange tether system.

Launch costs

• Estimates of the cost per pound of launching cargo or people from the Moon vary and the cost impacts of future technological improvements are difficult to predict. An upper bound on the cost of launching material from the Moon might be about $40,000,000 per kilogram, based on dividing the Apollo program costs by the amount of material returned.^[89][90][91] At the other extreme, the incremental cost of launching material from the moon using an electromagnetic accelerator could be quite low. The efficiency of launching material from the Moon with a proposed electric accelerator is suggested to be about 50%.^[92] If the carriage of a mass driver weighs the same as the cargo, two kilograms must be accelerated to orbital velocity for each kilogram put into orbit. The overall system efficiency would then drop to 25%. So 1.4 kilowatt-hours would be needed to launch an incremental kilogram of cargo to low orbit from the Moon.^[93] At $0.1/kilowatt-hour, a typical cost for electrical power on Earth, that amounts to $0.16 for the energy to launch a kilogram of cargo into orbit. For the actual cost of an operating system, energy loss for power conditioning, the cost of radiating waste heat, the cost of maintaining all systems, and the interest cost of the capital investment are considerations. David R. Criswell believes that there is a potential for the cost of electrical power on the Moon to become enough less than the cost on Earth for electrical power to be exported from the Moon to Earth by microwave.^[94]
• Passengers cannot be divided into the parcel size suggested for the cargo of a mass driver, nor subjected to hundreds of gravities acceleration. However, technical developments could also affect the cost of launching passengers to orbit from the Moon. Instead of bringing all fuel and oxidizer from Earth, liquid oxygen could be produced from lunar materials and hydrogen should be available from the lunar poles. The cost of producing these on the Moon is yet unknown, but they will be more expensive than production costs on Earth. The situation of the local hydrogen is most open to speculation. As a rocket fuel, hydrogen could be extended by combining it chemically with silicon to form silane,^[95] which has yet to be demonstrated in an actual rocket engine. In the absence of more technical developments, the cost of transporting people from the Moon will be an impediment to colonization.

Surface to and from cis-Lunar space

A cis-Lunar transport system has been proposed using tethers to achieve momentum exchange.^[96] This system requires zero net energy input, and could not only retrieve payloads from the Lunar surface and transport them to Earth, but could also soft land payloads on to the Lunar surface.

Economic development

For long term sustainability, a space colony should be close to self-sufficient. Mining and refining the Moon's materials on-site – for use both on the Moon and elsewhere in the Solar System – could provide an advantage over deliveries from Earth, as they can be launched into space at a much lower energy cost than from Earth. It is possible that large amounts of matter will need to be launched into space for interplanetary exploration in the 21st century, and the lower cost of providing goods from the Moon might be attractive.^[74]

Space-based materials processing

In the long term, the Moon will likely play an important role in supplying space-based construction facilities with raw materials.^[88] Zero gravity allows for the processing of materials in ways impossible or difficult on Earth, such as "foaming" metals, where a gas is injected into a molten metal, and then the metal is annealed slowly. On Earth, the gas bubbles rise and burst, but in a zero gravity environment, that does not happen. Annealing is a process that requires large amounts of energy, as a material is kept very hot for an extended period of time. (This allows the molecular structure to realign.) Materials which cannot be alloyed or mixed on Earth because of gravity-field effects on density differences could be combined in space, resulting in composites which could have exceptional qualities. (This is the foundation of the free MoonBaseOne game that teaches children about space.)

Exporting material to Earth

Exporting material to Earth in trade from the Moon is more problematic due to the cost of transportation, which will vary greatly if the Moon is industrially developed (see above). One suggested trade commodity, Helium-3 (³He) from the solar wind, is thought to have accumulated on the Moon's surface over billions of years, but occurs only rarely on Earth. Helium might be present in the Lunar regolith in quantities of 0.01 ppm to 0.05 ppm (depending on soil). In 2006 ³He had a market price of about $46,500 per troy ounce ($1500/gram, $1.5M/kg), more than 120 times the value per unit weight of gold and over eight times the value of rhodium.

In the future ³He may have a role as a fuel in thermonuclear fusion reactors.^[97]

Exporting propellant obtained from lunar water

To reduce the cost of transport, the Moon could store propellants produced from lunar water at one or several depots between the Earth and the Moon, to resupply rockets or satellites in earth orbit.^[98] The Shackleton Energy Company estimate investment in this infrastructure could cost around $25 billion.^[99]

Solar power satellites[edit]

Gerard K. O'Neill, noting the problem of high launch costs in the early 1970s, came up with the idea of building Solar Power Satellites in orbit with materials from the Moon.^[100] Launch costs from the Moon will vary greatly if the Moon is industrially developed (see above). This proposal was based on the contemporary estimates of future launch costs of the space shuttle.

On 30 April 1979 the Final Report "Lunar Resources Utilization for Space Construction" by General Dynamics Convair Division under NASA contract NAS9-15560 concluded that use of Lunar resources would be cheaper than terrestrial materials for a system comprising as few as thirty Solar Power Satellites of 10 GW capacity each.^[101]

In 1980, when it became obvious NASA's launch cost estimates for the space shuttle were grossly optimistic, O'Neill et al. published another route to manufacturing using Lunar materials with much lower startup costs.^[102] This 1980s SPS concept relied less on human presence in space and more on partially self-replicating systems on the Lunar surface under telepresence control of workers stationed on Earth.

Mercantilism

From Wikipedia, the free encyclopedia

   

An imaginary seaport with a transposed Villa Medici, painted by Claude Lorrain around 1637, at the height of mercantilism

 

Mercantilism is an economic theory practice, commonly used in Europe from the 16th to the 18th century that promoted governmental regulation of a nation’s economy for the purpose of augmenting state power at the expense of rival national powers. It was the economic counterpart of political absolutism.^[1] It includes a national economic policy aimed at accumulating monetary reserves through a positive balance of trade, especially of finished goods. Mercantilism dominated Western European economic policy and discourse from the 16th to late-18th centuries.^[2] Mercantilism was a cause of frequent European wars and also motivated colonial expansion. Mercantilist theory varied in sophistication from one writer to another and evolved over time. High tariffs, especially on manufactured goods, are an almost universal feature of mercantilist policy. Other policies have included:

• Building overseas colonies;
• Forbidding colonies to trade with other nations;
• Monopolizing markets with staple ports;
• Banning the export of gold and silver, even for payments;
• Forbidding trade to be carried in foreign ships;
• Export subsidies;
• Promoting manufacturing with research or direct subsidies;
• Limiting wages;
• Maximizing the use of domestic resources;
• Restricting domestic consumption with non-tariff barriers to trade.

Mercantilism in its simplest form was bullionism, but mercantilist writers emphasized the circulation of money and rejected hoarding. Their emphasis on monetary metals accords with current ideas regarding the money supply, such as the stimulative effect of a growing money supply. Specie concerns have since been rendered moot by fiat money and floating exchange rates. In time, the heavy emphasis on money was supplanted by industrial policy, accompanied by a shift in focus from the capacity to carry on wars to promoting general prosperity. Mature neomercantilist theory recommends selective high tariffs for "infant" industries or to promote the mutual growth of countries through national industrial specialization^{[citation needed]}.

The term "mercantile system" was used by its foremost critic Adam Smith,^[3] but "mercantilisme" had been used earlier by Mirabeau. While many nations practised it, one leading exemplar was France, the economically most important state, where King Louis XIV followed the guidance of Jean Baptiste Colbert, his controller general of finances (1662-83). They were determined that the state should rule in the economic realm as it did in the diplomatic, and that the interests of the state as identified by the king were superior to those of merchants and everyone else. The goal of economic policies was to build up the state, especially in an age of incessant warfare, and the state should look for ways to strengthen the economy and weaken foreign adversaries.^[4]

Influence

Mercantilism was the dominant school of thought in Europe throughout the late Renaissance and early modern period (from the 15th to the 18th century). Mercantilism encouraged the many intra-European wars of the period and arguably fueled European expansion and imperialism – both in Europe and throughout the rest of the world – until the 19th century or early 20th century.

Evidence of mercantilistic practices appear in early modern Venice, Genoa, and Pisa regarding control of the Mediterranean trade of bullion. However, as a codified school, mercantilism's real birth is marked by the empiricism of the Renaissance, which first began to quantify large-scale trade accurately.^[5]

England began the first large-scale and integrative approach to mercantilism during the Elizabethan Era (1558–1603). An early statement on national balance of trade appeared in Discourse of the Common Weal of this Realm of England, 1549: "We must always take heed that we buy no more from strangers than we sell them, for so should we impoverish ourselves and enrich them."^[6] The period featured various but often disjointed efforts by the court of Queen Elizabeth to develop a naval and merchant fleet capable of challenging the Spanish stranglehold on trade and of expanding the growth of bullion at home. Queen Elizabeth promoted the Trade and Navigation Acts in Parliament and issued orders to her navy for the protection and promotion of English shipping. A systematic and coherent explanation of balance of trade was made public through Thomas Mun's argument England's Treasure by Forraign Trade, or the Balance of our Forraign Trade is The Rule of Our Treasure. It was written in the 1620s and published in 1664.^[7]

These efforts organized national resources sufficiently in the defense of England against the far larger and more powerful Spanish Empire, and in turn paved the foundation for establishing a global empire in the 19th century.^{[citation needed]} The authors noted most for establishing the English mercantilist system include Gerard de Malynes and Thomas Mun, who first articulated the Elizabethan system, which in turn was then developed further by Josiah Child. Numerous French authors helped cement French policy around mercantilism in the 17th century. This French mercantilism was best articulated by Jean-Baptiste Colbert (in office, 1665–1683), though policy liberalised greatly under Napoleon.

In Europe, academic belief in mercantilism began to fade in the late 18th century, especially in Britain, in light of the arguments of Adam Smith and the classical economists. The repeal of the Corn Laws by Robert Peel symbolised the emergence of free trade as an alternative system.

Neomercantilism is a 20th-century economic policy that uses the ideas and methods of neoclassical economics. The new mercantilism has different goals and focuses on more rapid economic growth based on advanced technology. It promotes such policies as substitution state taxing, subsidizing, spending, and general regulatory powers for tariffs and quotas, and protection through the formation of supranational trading blocs.^[8]

Theory

Most of the European economists who wrote between 1500 and 1750 are today generally considered mercantilists; this term was initially used solely by critics, such as Mirabeau and Smith, but was quickly adopted by historians. Originally the standard English term was "mercantile system." The word "mercantilism" was introduced into English from German in the early 19th century.

The bulk of what is commonly called "mercantilist literature" appeared in the 1620s in Great Britain.^[9] Smith saw English merchant Thomas Mun (1571–1641) as a major creator of the mercantile system, especially in his posthumously published Treasure by Foreign Trade (1664), which Smith considered the archetype or manifesto of the movement.^[10] Perhaps the last major mercantilist work was James Steuart’s Principles of Political Economy published in 1767.^[9]

"Mercantilist literature" also extended beyond England. Italy and France produced noted writers of mercantilist themes including Italy's Giovanni Botero (1544–1617) and Antonio Serra (1580–?); France's, Jean Bodin, Colbert and other physiocrats. Themes also existed in writers from the German historical school from List, as well as followers of the "American system" and British "free-trade imperialism," thus stretching the system into the 19th century. However, many British writers, including Mun and Misselden, were merchants, while many of the writers from other countries were public officials. Beyond mercantilism as a way of understanding the wealth and power of nations, Mun and Misselden are noted for their viewpoints on a wide range of economic matters.^[11]

Merchants in Venice

The Austrian lawyer and scholar Philipp Wilhelm von Hornick, in his Austria Over All, If She Only Will of 1684, detailed a nine-point program of what he deemed effective national economy, which sums up the tenets of mercantilism comprehensively:^[12]

• That every little bit of a country's soil be utilized for agriculture, mining or manufacturing.
• That all raw materials found in a country be used in domestic manufacture, since finished goods have a higher value than raw materials.
• That a large, working population be encouraged.
• That all export of gold and silver be prohibited and all domestic money be kept in circulation.
• That all imports of foreign goods be discouraged as much as possible.
• That where certain imports are indispensable they be obtained at first hand, in exchange for other domestic goods instead of gold and silver.
• That as much as possible, imports be confined to raw materials that can be finished [in the home country].
• That opportunities be constantly sought for selling a country's surplus manufactures to foreigners, so far as necessary, for gold and silver.
• That no importation be allowed if such goods are sufficiently and suitably supplied at home.

Other than Von Hornick, there were no mercantilist writers presenting an overarching scheme for the ideal economy, as Adam Smith would later do for classical economics. Rather, each mercantilist writer tended to focus on a single area of the economy.^[13] Only later did non-mercantilist scholars integrate these "diverse" ideas into what they called mercantilism. Some scholars thus reject the idea of mercantilism completely, arguing that it gives "a false unity to disparate events". Smith saw the mercantile system as an enormous conspiracy by manufacturers and merchants against consumers, a view that has led some authors, especially Robert E. Ekelund and Robert D. Tollison to call mercantilism "a rent-seeking society". To a certain extent, mercantilist doctrine itself made a general theory of economics impossible.^[14] Mercantilists viewed the economic system as a zero-sum game, in which any gain by one party required a loss by another.^[15] Thus, any system of policies that benefited one group would by definition harm the other, and there was no possibility of economics being used to maximize the "commonwealth", or common good.^[16] Mercantilists' writings were also generally created to rationalize particular practices rather than as investigations into the best policies.^[17]

Mercantilist domestic policy was more fragmented than its trade policy. While Adam Smith portrayed mercantilism as supportive of strict controls over the economy, many mercantilists disagreed. The early modern era was one of letters patent and government-imposed monopolies; some mercantilists supported these, but others acknowledged the corruption and inefficiency of such systems. Many mercantilists also realized that the inevitable results of quotas and price ceilings were black markets. One notion mercantilists widely agreed upon was the need for economic oppression of the working population; laborers and farmers were to live at the "margins of subsistence". The goal was to maximize production, with no concern for consumption. Extra money, free time, or education for the "lower classes" was seen to inevitably lead to vice and laziness, and would result in harm to the economy.^[18]

Infinite growth

The mercantilists saw a large population as a form of wealth which made possible the development of bigger markets and armies. The opposing doctrine of physiocracy predicted that mankind would outgrow its resources. The idea of mercantilism was to protect the markets, but it also helped to maintain the agriculture and those who were dependent upon it.

Origins

Scholars debate over why mercantilism dominated economic ideology for 250 years.^[19] One group, represented by Jacob Viner, sees mercantilism as simply a straightforward, common-sense system whose logical fallacies remained opaque to people at the time, as they simply lacked the required analytical tools.

The second school, supported by scholars such as Robert B. Ekelund, portrays mercantilism not as a mistake, but rather as the best possible system for those who developed it. This school argues that rent-seeking merchants and governments developed and enforced mercantilist policies. Merchants benefited greatly from the enforced monopolies, bans on foreign competition, and poverty of the workers. Governments benefited from the high tariffs and payments from the merchants. Whereas later economic ideas were often developed by academics and philosophers, almost all mercantilist writers were merchants or government officials.^[20]

Monetarism offers a third explanation for mercantilism. European trade exported bullion to pay for goods from Asia, thus reducing the money supply and putting downward pressure on prices and economic activity. The evidence for this hypothesis is the lack of inflation in the British economy until the Revolutionary and Napoleonic wars when paper money came into vogue.

A fourth explanation lies in the increasing professionalisation and technification of the wars of the era, which turned the maintenance of adequate reserve funds (in the prospect of war) into a more and more expensive and eventually competitive business.

Mercantilism developed at a time of transition for the European economy. Isolated feudal estates were being replaced by centralized nation-states as the focus of power. Technological changes in shipping and the growth of urban centres led to a rapid increase in international trade.^[21]

Mercantilism focused on how this trade could best aid the states. Another important change was the introduction of double-entry bookkeeping and modern accounting. This accounting made extremely clear the inflow and outflow of trade, contributing to the close scrutiny given to the balance of trade.^[22] Of course, the impact of the discovery of America cannot be ignored.^{[citation needed]} New markets and new mines propelled foreign trade to previously inconceivable heights. The latter led to "the great upward movement in prices" and an increase in "the volume of merchant activity itself".^[23]
Prior to mercantilism, the most important economic work done in Europe was by the medieval scholastic theorists. The goal of these thinkers was to find an economic system compatible with Christian doctrines of piety and justice. They focused mainly on microeconomics and on local exchanges between individuals. Mercantilism was closely aligned with the other theories and ideas that began to replace the medieval worldview. This period saw the adoption of the very Machiavellian realpolitik and the primacy of the raison d'état in international relations. The mercantilist idea of all trade as a zero-sum game, in which each side was trying to best the other in a ruthless competition, was integrated into the works of Thomas Hobbes. The dark view of human nature also fit well with the Puritan view of the world, and some of the most stridently mercantilist legislation, such as the Navigation Ordinance of 1651, was enacted by the government of Oliver Cromwell.^[24]

Jean-Baptiste Colbert's work in seventeenth century France came to exemplify classical mercantilism. In the English-speaking world its ideas were criticized by Adam Smith with the publication of The Wealth of Nations in 1776 and later David Ricardo with his explanation of comparative advantage. Mercantilism was rejected by Britain and France by the mid-19th century. The British Empire embraced free-trade and used its power as the financial centre of the world to promote the same. The Guyanese historian Walter Rodney describes mercantilism as the period of the world-wide development of European commerce, which began in the fifteenth century with the voyages of Portuguese and Spanish explorers to Africa, Asia and the New World.

Policies

French finance minister and mercantilist Jean-Baptiste Colbert served for over 20 years.

Mercantilist ideas were the dominant economic ideology of all of Europe in the early modern period, and most states embraced it to a certain degree. Mercantilism was centred in England and France, and it was in these states that mercantilist polices were most often enacted.

France

Mercantilism arose in France in the early 16th century soon after the monarchy had become the dominant force in French politics. In 1539, an important decree banned the importation of woolen goods from Spain and some parts of Flanders. The next year, a number of restrictions were imposed on the export of bullion.^[25]

Over the rest of the sixteenth century further protectionist measures were introduced. The height of French mercantilism is closely associated with Jean-Baptiste Colbert, finance minister for 22 years in the 17th century, to the extent that French mercantilism is sometimes called Colbertism. Under Colbert, the French government became deeply involved in the economy in order to increase exports.
Protectionist policies were enacted that limited imports and favored exports. Industries were organized into guilds and monopolies, and production was regulated by the state through a series of over a thousand directives outlining how different products should be produced.^[26]

To encourage industry, foreign artisans and craftsmen were imported. Colbert also worked to decrease internal barriers to trade, reducing internal tariffs and building an extensive network of roads and canals. Colbert's policies were quite successful, and France's industrial output and economy grew considerably during this period, as France became the dominant European power. He was less successful in turning France into a major trading power, and Britain and the Netherlands remained supreme in this field.^[26]

Great Britain

In England, mercantilism reached its peak during the Long Parliament government (1640–1660). Mercantilist policies were also embraced throughout much of the Tudor and Stuart periods, with Robert Walpole being another major proponent. In Britain, government control over the domestic economy was far less extensive than on the Continent, limited by common law and the steadily increasing power of Parliament.^[27] Government-controlled monopolies were common, especially before the English Civil War, but were often controversial.^[28]

The Anglo-Dutch Wars were fought between the English and the Dutch for control over the seas and trade routes.

With respect to its colonies, British mercantilism meant that the government and the merchants became partners with the goal of increasing political power and private wealth, to the exclusion of other empires. The government protected its merchants – and kept others out – by trade barriers, regulations, and subsidies to domestic industries in order to maximize exports from and minimize imports to the realm. The government had to fight smuggling – which became a favorite American technique in the 18th century to circumvent the restrictions on trading with the French, Spanish or Dutch. The goal of mercantilism was to run trade surpluses, so that gold and silver would pour into London. The government took its share through duties and taxes, with the remainder going to merchants in Britain. The government spent much of its revenue on a superb Royal Navy, which not only protected the British colonies but threatened the colonies of the other empires, and sometimes seized them. Thus the British Navy captured New Amsterdam (New York) in 1664. The colonies were captive markets for British industry, and the goal was to enrich the mother country.^[29]
British mercantilist writers were themselves divided on whether domestic controls were necessary. British mercantilism thus mainly took the form of efforts to control trade. A wide array of regulations was put in place to encourage exports and discourage imports. Tariffs were placed on imports and bounties given for exports, and the export of some raw materials was banned completely. The Navigation Acts expelled foreign merchants from England's domestic trade. The nation aggressively sought colonies and once under British control, regulations were imposed that allowed the colony to only produce raw materials and to only trade with Britain. This led to friction with the inhabitants of these colonies, and mercantilist policies (such as forbidding trade with other empires and controls over smuggling) were a major irritant leading to the American Revolution.

Over all, however, mercantilist policies had a positive impact on Britain helping turn it into the world's dominant trader, and the global hegemon.^{[citation needed]} One domestic policy that had a lasting impact was the conversion of "waste lands" to agricultural use. Mercantilists felt that to maximize a nation's power all land and resources had to be used to their utmost, and this era thus saw projects like the draining of The Fens.^[30]

Mercantilism helped create trade patterns such as the triangular trade in the North Atlantic, in which raw materials were imported to the metropolis and then processed and redistributed to other colonies.

Other countries

The other nations of Europe also embraced mercantilism to varying degrees. The Netherlands, which had become the financial centre of Europe by being its most efficient trader, had little interest in seeing trade restricted and adopted few mercantilist policies. Mercantilism became prominent in Central Europe and Scandinavia after the Thirty Years' War (1618–1648), with Christina of Sweden, Jacob Kettler of Courland, Christian IV of Denmark being notable proponents. The Habsburg Holy Roman Emperors had long been interested in mercantilist policies, but the vast and decentralized nature of their empire made implementing such notions difficult.

Some constituent states of the empire did embrace Mercantilism, most notably Prussia, which under Frederick the Great had perhaps the most rigidly controlled economy in Europe. During the economic collapse of the seventeenth century Spain had little coherent economic policy, but French mercantilist policies were imported by Philip V with some success. Russia under Peter I (Peter the Great) attempted to pursue mercantilism, but had little success because of Russia's lack of a large merchant class or an industrial base.

Wars and imperialism

Mercantilism was economic warfare and was well suited to an era of military warfare.^[31] Since the level of world trade was viewed as fixed, it followed that the only way to increase a nation's trade was to take it from another. A number of wars, most notably the Anglo-Dutch Wars and the Franco-Dutch Wars, can be linked directly to mercantilist theories. Most wars had other causes but they reinforced mercantilism by clearly defining the enemy, and justified damage to the enemy's economy.

Mercantilism fueled the imperialism of this era, as many nations expended significant effort to build new colonies that would be sources of gold (as in Mexico) or sugar (as in the West Indies), as well as becoming exclusive markets. European power spread around the globe, often under the aegis of companies with government-guaranteed monopolies in certain defined geographical regions, such as the Dutch East India Company or the British Hudson's Bay Company (operating in present-day Canada).

Criticisms

Much of Adam Smith's The Wealth of Nations is an attack on mercantilism.

Adam Smith and David Hume were the founding fathers of anti-mercantilist thought. A number of scholars found important flaws with mercantilism long before Adam Smith developed an ideology that could fully replace it. Critics like Hume, Dudley North, and John Locke undermined much of mercantilism, and it steadily lost favor during the 18th century.

In 1690, John Locke argued that prices vary in proportion to the quantity of money. Locke's Second Treatise also points towards the heart of the anti-mercantilist critique: that the wealth of the world is not fixed, but is created by human labor (represented embryonically by Locke's labor theory of value). Mercantilists failed to understand the notions of absolute advantage and comparative advantage (although this idea was only fully fleshed out in 1817 by David Ricardo) and the benefits of trade.^[32]

For instance, if Portugal was a more efficient producer of wine than England, yet in England cloth could be produced more efficiently than it could in Portugal. Thus if Portugal specialized in wine and England in cloth, both states would end up better off if they traded. This is an example of the reciprocal benefits of trade due to a comparative advantage. In modern economic theory, trade is not a zero-sum game of cutthroat competition because both sides can benefit.

Hume famously noted the impossibility of the mercantilists' goal of a constant positive balance of trade^{[citation needed]}. As bullion flowed into one country, the supply would increase and the value of bullion in that state would steadily decline relative to other goods. Conversely, in the state exporting bullion, its value would slowly rise. Eventually it would no longer be cost-effective to export goods from the high-price country to the low-price country, and the balance of trade would reverse itself.
Mercantilists fundamentally misunderstood this, long arguing that an increase in the money supply simply meant that everyone gets richer.^[33]

The importance placed on bullion was also a central target, even if many mercantilists had themselves begun to de-emphasize the importance of gold and silver. Adam Smith noted at the core of the mercantile system was the "popular folly of confusing wealth with money," bullion was just the same as any other commodity, and there was no reason to give it special treatment.^[9] More recently, scholars have discounted the accuracy of this critique. They believe Mun and Misselden were not making this mistake in the 1620s, and point to their followers Josiah Child and Charles Davenant, who, in 1699, wrote: "Gold and Silver are indeed the Measure of Trade, but that the Spring and Original of it, in all nations is the Natural or Artificial Product of the Country; that is to say, what this Land or what this Labour and Industry Produces."^[34] The critique that mercantilism was a form of rent-seeking has also seen criticism, as scholars such Jacob Viner in the 1930s point out that merchant mercantilists such as Mun understood that they would not gain by higher prices for English wares abroad.^[35]

The first school to completely reject mercantilism was the physiocrats, who developed their theories in France. Their theories also had several important problems, and the replacement of mercantilism did not come until Adam Smith published The Wealth of Nations in 1776. This book outlines the basics of what is today known as classical economics. Smith spends a considerable portion of the book rebutting the arguments of the mercantilists, though often these are simplified or exaggerated versions of mercantilist thought.^[20]

Scholars are also divided over the cause of mercantilism's end. Those who believe the theory was simply an error hold that its replacement was inevitable as soon as Smith's more accurate ideas were unveiled. Those who feel that mercantilism was rent-seeking hold that it ended only when major power shifts occurred. In Britain, mercantilism faded as the Parliament gained the monarch's power to grant monopolies. While the wealthy capitalists who controlled the House of Commons benefited from these monopolies, Parliament found it difficult to implement them because of the high cost of group decision making.^[36]

Mercantilist regulations were steadily removed over the course of the Eighteenth Century in Britain, and during the 19th century the British government fully embraced free trade and Smith's laissez-faire economics. On the continent, the process was somewhat different. In France, economic control remained in the hands of the royal family and mercantilism continued until the French Revolution. In Germany mercantilism remained an important ideology in the 19th and early 20th centuries, when the historical school of economics was paramount.^[37]

Legacy

Adam Smith rejected the mercantilist focus on production, arguing that consumption was paramount to production. He added that mercantilism was popular among merchants because it was what is now called "rent seeking".^[38] However John Maynard Keynes argued that encouraging production was just as important as consumption, and he favoured the "new mercantilism". Keynes also noted that in the early modern period the focus on the bullion supplies was reasonable. In an era before paper money, an increase for bullion was one of the few ways to increase the money supply. Keynes said mercantilist policies generally improved both domestic and foreign investment. Domestic because the policies lowered the domestic rate of interest. And it increased investment by foreigners in the nation by tending to create a favorable balance of trade.^[39]

Keynes and other economists of the 20th century also realized the balance of payments is an important concern. Keynes also supported government intervention in the economy as necessity, as did mercantilism.^[40]

As of 2010^[update], the word "mercantilism" remains a pejorative term, often used to attack various forms of protectionism.^[41] The similarities between Keynesianism, and its successor ideas, with mercantilism have sometimes led critics to call them neo-mercantilism. Indeed, Paul Samuelson, writing within a Keynesian framework, defended mercantilism, writing: "With employment less than full and Net National Product suboptimal, all the debunked mercantilist arguments turn out to be valid."^[42]

Some other systems that do copy several mercantilist policies, such as Japan's economic system, are also sometimes called neo-mercantilist.^[43] In an essay appearing in the 14 May 2007 issue of Newsweek, business columnist Robert J. Samuelson argued that China was pursuing an essentially mercantilist trade policy that threatened to undermine the post-World War II international economic structure.^[44]

Murray Rothbard, representing the Austrian School of economics, describes it this way:

Mercantilism, which reached its height in the Europe of the seventeenth and eighteenth centuries, was a system of statism which employed economic fallacy to build up a structure of imperial state power, as well as special subsidy and monopolistic privilege to individuals or groups favored by the state. Thus, mercantilism held exports should be encouraged by the government and imports discouraged.^[45]

In one area economists rejected Smith well before Keynes: in the use of data. Mercantilists, who were generally merchants or government officials, gathered vast amounts of trade data and used it extensively in their research and writing. William Petty, a strong mercantilist, is generally credited with being the first to use empirical analysis to study the economy. Smith rejected this, arguing that deductive reasoning from base principles was the proper method to discover economic truths. Today, many schools of economics accept that both methods are important.

In specific instances, protectionist mercantilist policies also had an important and positive impact on the state that enacted them. Adam Smith himself, for instance, praised the Navigation Acts as they greatly expanded the British merchant fleet, and played a central role in turning Britain into the naval and economic superpower from the 18th Century onward.^[46] Some economists thus feel that protecting infant industries, while causing short-term harm, can be beneficial in the long term.