Why the current proposals for Space Tourism are a dead end

There are nowadays dozens, so not, hundreds of companies offering or planning to offer tourist trips to outer space. Most of this proposals only provide a flight up to a hundred kilometres above the surface of the Earth, technically this is outer space. But those trip only offers a few minutes outside our atmosphere, so we don’t consider this as “real” space travel.

Of course we believe that anyone should have the right to start his/her own space travel agency, we of course want to do same in a few years time, but we seriously doubt whether these current initiatives are helpful for the start-up of human settlement of Outer Space. First most space tourist companies are not interested in permanent settlement of space, since they didn’t have the budget to support such colonization programs.

But our second and most important argument is, that many space tourists companies, ask much money from their would-be costumers. There is a large range in prices, but they are usually in the order hundred thousands to millions of dollars a flight a person, this means that only a few people in the world can actually afford this. Further of the worlds millionaires only a small percentage is likely willing to pay a large sum of money for a few minutes in Outer space. So we expect that these initiatives wouldn’t succeed due to lack of sufficient demand.

Our conclusion is therefore that the current Space Tourist proposals are a dead-end to humanization of Space.

Advertisements

O’Neill Cylinders and spatial planning

This post was originally posted on blogspot.com on October 18, 2012

In an earlier post I discussed the potential of Bernal spheres and Stanford tori for city states, in this posting I will discuss several ideas for the spatial planning of O’Neill cylinders.

The ideas I will discuss here are not developed for space colonization as such, but can nevertheless be very inspiring for Space settlers. Especially for the larger space habitats spatial planning is an important topic. In this post I will discuss three proposals: O’Neill’s own idea, Ebenezer Howard’s garden cities and the ideas of Frank Lloyd Wright. The purpose of this post is not to force a certain spatial plan on to Space colonies, but rather to provide a framework for developing better societies.

Since O’Neill cylinders provide a large plot of usable land, they allows for more sophisticated spatial planning then smaller habitats. The latter will typically be highly populated and most of their usable land will be used for housing and closely related activities. Consequently the smaller habitats will lack any significant amount of nature (forests for example), while many, if not most, people will appreciate nature.

Since the days of O’Neill, the consensus among space colonization advocates (and we follow this) is that industry, agriculture and living should be separated (the first two should not be located inside space habitats), this is an important difference with terrestrial spatial planning. Combined with the practically unlimited resources in space, we are free to design the interior of an O’Neill cylinder as we like.

In his book, The high frontier, O’Neill has given an example of spatial planning. In chapter 5 he describes the build cities at the ends of each stroke of land, referred to as “valleys”, and using the land areas it self for villages, forests and parks.

It would be interesting to look at a few spatial planning concepts from the past. In the 1930s the American architect Frank Lloyd Wright  designed his famous Broadacre City. In this proposal “true” cities would disappear, while people would spread out over the country (for this reason his plan was not very popular outside the USA). One feature of this scheme was that each family receives a 4,000 square meter plot of land [1]. Which was to be developed according to wishes of the receiving family. While there many really good aspects to his vision, there is some important critique about the Broadacre City idea, which can be found here. A serious drawback of the original design is that it heavily depends on automobiles for transportation. In a space based nation, in which people are spread over many different space habitats, cars are really cumbersome to handle. As O’Neill explained the main modes of transportation in and between space habitats are space ships, maglevs, bicycles and walking [2].

My personal favorite is, however, the garden city, a concept developed by Ebenezer Howard around 1900. In short this urban design is an attempt to reconcile the city and the countryside. In Howard’s plan a garden city should require 6000 acres of land (which is approximately 25 square kilometers or 2428.2 hectare), of which 1000 acres are used for the actual city and the other 5000 acres are destined for agriculture [3]. As I have already said, most space habitat advocates favor a physical separation of agricultural and living areas. At first sight Howard’s idea seems to be outdated, and it is to some degree. Nevertheless I believe that this garden city concept is good starting point for our own spatial plans. We should look for alternative destination for these agricultural lands, a portion can be reserved for allotment gardens, while another portion is reserved for sport associations (think about field hockey clubs, rugby clubs and so on). In Howard’s original designs there is a remarkable lack of recreation areas (to be fair Howard planned a park in the center of his city, but this is one is to small for serious sport practice.)

The actual city itself, would be an annulus around this central park and would be divided into six wards, each with 5,000 inhabitants. This would give a total city population of 30,000 thousand, in addition a further 2,000 would live in the rural area of the city. Howard also thought about what to do when the city population would grow, unlike the natural course of urban growth by which new buildings are attached to the existing settlement, he foresaw to build new garden cities a few miles away of the old one. In fact he suggested to build a central city, a garden city with 55,000 inhabitants, first  and later to build six (normal) garden cities around it. The central city would serve as a regional center. This particular configuration is not feasible for a standard O’Neill Cylinder (diameter 6.4 km and length 32 km), but is we would increase these dimension s with a factor 5 (which would give an areal increase of a factor 25) then it would become an interesting option. However such O’Neill cylinders XL will not be realized in early space colonization.

A different but related concept is Columbia, Maryland. Like the conglomeration of garden cities, the different villages of Columbia are not one single area but separated by green areas (called the Tivoli garden). The city’s 100,000 residents [4] are spread among nine villages, with a land area of 82.7 square kilometers (compare this with a valley of 107.23 square kilometers). If we would organize a valley in a similar fashion as Columbia, than we would get a city with population of between 130,000 and 143,000 [5]. In order to keep this city mostly car-free, they designers envisioned a minibus-network.

As I have said at the beginning of this post, the purpose of the mentioned examples is to inspire the spatial planners of O’Neill cylinders. And I hope they will not make the same mistakes as those made by terrestrial urban planners. Space colonization is a nice occasion to experiment with innovation on spatial planning. Of course the specific spatial plans will depend on the political choices made by the owners/governments of space habitats, different political ideologies require different spatial plans. The examples I selected here, reflect my personal believes about decentralized republicanism with its preference for small non-urban communities as the framework for active citizens participation in public affairs.

Notes

[1] A valley of a typical O’Neill cylinder is 3.35 by 32 kilometers, which is 107.2 million square meters. And using Wrights 4,000 square meters per family, we can calculate that a valley provides land for 26,800 families.

[2] I will discuss transportation in space colonies more deeply in another post.

[3] Using the standard dimensions of a O’Neill Cylinder (length 32 km, diameter 6.4 km), we can calculate that each valley can host 4.4 garden cities. This gives a total population of 141,000 people for each valley (4.4×32,000).

[4] Originally (in 1966) it was estimated that Columbia would have 110,000 residents in 1980.

[5] The lower estimate is based on Columbia’s current population, the higher one the estimate from note [4].

Bernal Spheres, Stanford tori and the return of the polis.

This post was originally published on blogspot.com on April 23, 2012; updated June 13, 2014.

In this post I want to share some thoughts I have had for many years, concerning the ancient Greek city-state, or polis (plural poleis) and what we can learn from them.

Both O’Neill’s Island I and its main competitor the so-called Stanford torus are designed for some ten thousands of inhabitants, roughly the population of many small cities. And since space habitants of this kind can easily moved to any place within our (inner) Solar system, they can enjoy a great amount of isolation just by keeping distance from other space colonies. Furthermore the abundance of space resources makes economic self-sufficiency not only feasible but also very likely.

Here on Earth no country can turn to a policy of full autarky without paying a huge price. Effectively only very primitive societies can be autarkic without giving up current wealth. One reason of modern globalization is that highly technological industries require large amounts of various resources, of which many are both rare and spread over different parts of the world. Some resources are as good as exclusively found at one place on Earth. Some argue that this interdependence promotes world peace, while on the other hand  we see that competition of scarce resources actually lead to many international conflicts.

In space there is a different situation, since there are a lot of recourse rich asteroids. Actually some “small” asteroids contains a few times more resources than anything ever dug up by Mankind, not only these asteroids have a huge abundance of resources but they also contain virtually all chemical elements needed by highly industrialized societies. A second difference is that competition among space colonies for resources will be low, due to great amount of asteroids, reducing tension among Spacer societies.

We can easily imagine that a small space colony, type Bernal sphere or Stanford torus is located near a small asteroid (dimension less than 1km). Such space society will be economically and politically independent from any other state (whether Spacer or terrestrial). This comes very close to the ancient Greek ideal of the polis: a political independent community of a few thousand people and economically self-sufficient.

Since the time of the ancient Greeks the ideal of small independent communities have repeatedly promoted by political activists. But these ideas and initiatives are repeatedly defeated in favour of the nation-state. A modern incarnation of this attitude is Communalism as conceived by Murray Bookchin. Bookchin, who stood in the anarchist tradition, opposed the nation-state, because it is undemocratic and a tool for corporate interest. Instead he argued that people should organize direct democracy at municipal level. And in a next stage, such municipalities should organize themselves into confederations, these confederations should compete with the Nation State for power. Confederations of municipalities differ from nations in an important way: the municipality is the primary political unit and the municipal citizens’ assembly is the Sovereign; the confederation is just an organization for cooperation and joint action by municipalities, and the representatives of the municipalities in the confederal council are purely coordinating and administrative.

Personally I believe that Communalism and its aims are not realistic, on Earth, because nation states are too well-organized and most terrestrial people don’t care about politics in general, and specially they don’t care about the Nation State. I suppose that most readers of this blog have never heard about Communalism before. On Earth I see no future for Communalism and related ideologies, but in Space Communalism and its idea may play a major role. Although I am not a Communalist myself (mainly because I disagree with its anti-capitalist nature), I believe that Communalism can provide valuable insights on how to organize Space colonies.

Some Space colonies may opt for Communalism, while other colonies will try other forms of government. But I believe there is a future for small polis based political communities in Space.

Inside view of a Bernal sphere

Interior including human powered airplane

 

 

Outside view of a Bernal sphere

Bernal Spheres - exterior

 

Planetary chauvinism

This post was originally posted on blogpot.com on July 31, 2012

In this post I will deal with the subject of planetary chauvinism and more specifically I will explain what planetary chauvinism is and why it is dangerous.

Essentially planetary chauvinism is the idea that human life should be based on the surface of a planet or planet-like object, such as the moon. In several earlier posts I have presented my objections against terraforming, lunar settlement programs and the colonization of Mars. All of these “space” colonization proposals are based on planetary chauvinism.

The origins of planetary chauvinist attitudes are simply based on psychology and ignorance. Many people believe that since humans have always lived on a planetary surface for ever we should do so in the future. Of course this is a logical fallacy, some practices we humans have done for centuries, slavery for instance, are now universally rejected or abolished. The other pillar of planetary chauvinism is ignorance, although many are familiar with space station like mir and the ISS, not very much people seem to know about the designs of space habitats capable of accommodating several thousands of people. Nor are there many people who realize that asteroids instead of planets or the moon are the true treasures of our solar system.

The question is why planetary chauvinism is dangerous. Many so-called “space programs”, regardless whether they are pursued by governments or private parties, are focused  on creating permanent bases on the moon or Mars. Although a lot of people seems to know about the dangers of low gravity on human health, the simple solution, rotating space habits in free space, is almost unknown outside the space advocacy movement. Not only is the low gravity of the moon and Mars a problem, but space habitats are actually cheaper than terraforming Mars, building domed cities on the moon. Why should we waste money on settling other planets, while with less money we can do the same job with free space habitats?

But the main danger of planetary chauvinism is that it will undermine the public support of any future space settlement program. Many ordinary people nowadays associate space colonization with settlements on Mars or on planets in other system. Since most people understand that these projects are costly and will take centuries to complete, they will tend to argue not to spend any money on those projects, regardless whether this is through taxation or private donations.

Planetary chauvinism with its narrow mind undermines the attempts to show the general public the real prospects of space development programs: the utilization of the resources from Near Earth Objects and the creation of space habitats. And by doing so planetary chauvinism is working against any serious space settlement program, therefore it is important to combat planetary chauvinism.

Breakthrough artificial egg cells

This post was originally posted on blogspot.com on November 24, 2012

The following article on BBC News describes a new technology to create egg cells, and although this technology currently only works for mice, I think this is an important development. In this post I will discuss why discoveries like this one are important for space colonization programs. In an earlier post I discussed some applications for artificial reproduction in space colonization.

My main point in that post was the need of a large gene pole. A low degree of genetic diversity will lead to inbreeding, which is usually associated with increased risk of genetic disorders. Unless we will apply strict genetic screening of immigrants, space populations will likely only exist for some generations. Even with genetic screening, we have the problem that most people are carriers of a few defect genes. The only way to solve the problem of a small gene pool, is to increase diversity. This can be done in two-way: massive immigration or import of human gametes.

Large scale immigration has multiple side issues: from a technical point of view we have to deal with the bottleneck to space, current rocket based space launch systems have limited capacity to send people to space. (We believe that all proposals for non-rocket space launch, are unlikely to developed soon, see also this post.) All best case scenarios predict that only a few hundred people can emigrate to space each year.

Another issue related to mass immigration is social-cultural and political. Space communities will most likely have very restrictive admission policies, and will select only those potential immigrants on whether they have certain desired qualifications and whether they do share the political ideology of a particular space colony. For example a more socialist oriented space colony is not likely to be willing to accept immigrants who are opposed to socialism.

The second solution for increasing genetic diversity is by importing human gametes. Human sperm can easily be collected on Earth, space governments could offer reasonable cash amounts to men in return of their sperm. Once collected, sperm is easily stored and transported, one launch could easily carry the sperm of several thousand males. The collection of human egg cells is much more difficult, eggs or ovary tissue can only be collected through surgery. It is clear that buying human eggs is much more expensive than human sperm, we have now also to pay for the surgery.

However this problem would be solved if we would be able to make egg cells from skin tissue, which can be collected in almost every reasonable hospital in the world. The procedure of collecting skin tissue is much less intrusive for women. Tissue cultures are just like sperm samples easy to store and transport into outer space.

Sperm donation and artificial egg cells will make it possible for Space communities to develop gene banks with high genetic diversity without the difficulties arising from (mass) immigration.

More:

Artificial sperm is also possible http://www.bbc.co.uk/news/health-14404183

Why rockets are necessary for Space Colonization

This post was originally posted on blogspot.com on May 11, 2012

In this posting I will argue why we should stick with chemical rockets for our program of space colonization.

Many proponents of space colonization are in favour of several types of non rocket space launch. Most commonly proposed are space elevators and projectile launchers, their advocates favor these because they believe that is launch methods will lower the costs of launching objects into orbit (and beyond). At this moment it costs us$10,000 to us$25,000  per kilogram to launch something into space (Wikipedia, see here) and its argued that the minimum energy required for space launch is much less than with rockets and so it would, in theory, to lower the costs of space launch (the Wikipedia article don’t show any explanation for this claim, so I am somewhat skeptical about it).

Although multiple launch schemes are proposed in the past, however no one, save for chemical rockets, has actually proven to be successful. Yes, there have been a multiple test of several proposed systems, but none of them has ever launched anything in space. Chemical rockets are proven technology, quite easy to build. This will lower our development costs, this is very important if we want to start with space colonization as soon as possible. Although the several proposals for non rocket space launch will work in theory, and they may lower launch costs, we cannot know when these methods are ready to use. Here we can compare this with the research on nuclear fusion power, which has started at same time as nuclear fission, but today there are still no commercial fusion power plants (at this moment they are not expected before the 2050s).

If, say, research will show that rail guns are the most efficient method of space launch, but it will take fifty years before this will be operational, then we should not go for it. Why? Because no one will invest in such project if there is no guarantee that it will work, while in the meantime it will not generate any revenue. Unlike in the case of fusion power research, which is funded by governments, we cannot afford to waste our time with developing speculative technology. Many space advocacy groups have lost their credibility because they were not able to come with realistic plans to get started with space development within the next ten to fifteen years. With realistic plans I mean plans that not rely on governmental funding and have clear ideas about generating revenue for repaying investors. In an upcoming post I will present a plan, which I believe will satisfy my criteria. Instead many “space advocacy” groups are wasting their time and their money with lobbying, not very successful if we look at the miserable state of the US space program. Also in an upcoming post I will argue why space tourism will not helpful for space colonization, this because many space advocates believe that space tourism will act as a catalyst for space development.

Since at this moment chemical rockets are the only proven method of space launch and we do not have the time for develop more speculative technologies, we should stick with chemical rockets. Even if could reduce launch costs, we have to take into account development cost and since we cannot predict the actual amount of time and money spent in research, we cannot afford to take this risk. Not that I am against research, but we should devote most of our funds and time for solving the real issues of space colonization, not for reinventing the wheel over and over again. This is actually what NASA is doing, while the Russians are using the same launch system for decades, with several improvements over time.

Rockets are maybe not the most efficient launch system, but at least they work.

Noah’s Ark 2.0

This post was originally posted on blogspot.com on April 23, 2012

In our post on meat production in outer space we briefly addressed the problem of transporting herds of animals from Earth to Space colonies. Transporting small animals like dogs and cats, will not a big deal. But larger animals like cattle or horses are much more difficult. The primary problem is with mass, launching a certain mass of payload from the surface of the Earth, cost much more mass of fuel, see Tsiolkovsky’s rocket equation. This equation tells us that it will be almost impossible to launch an elephant from Earth to Space colony. Recall that from an orbit around our blue planet to the Lagrange points of the Earth-Sun system, will only take a little amount of energy and propellant mass.

If we want to bring animals to Space colonies, we should take as little as possible. In theory we should take only a couple, one male and one female, and then breed from them as many as necessary. But there is one big problem with this approach: inbreeding. In order to reduce the negative effects of inbreeding we should increase the number of transported animals, and so increasing transportation costs. There is a simple solution for these dilemma: nowadays sperm and eggs (female gametes) can easily be stored. And by this method a relatively small space craft can transport a large collection of genetic information of several species and multiple individuals of each species. When this cargo of sperm and eggs arrives at the Space colony, scientists can create new embryos by using in vitro fertilization.

You may argue that even if we create embryos we will still need some female of each specie. This is true to a certain degree, yes we need a womb, but this doesn’t need to be one of the same species. Currently scientists are researching interspecific pregnancy, this made it possible to implant, say a horse embryo, into a cow. A potential problem with this technology is as follows: a certain female animal may carry only a young with a smaller than a certain size, for example: a domestic cat cannot give birth to a bovine calf. But even this problem is possibly to solve. We can imagine that some small animal A gives birth to little bigger (at adulthood) animal B, which on her turn can give birth to an ever bigger (at adulthood) animal, etcetera. Of course this procedure will take some time, but it is possibly our only option.

A technologically more advanced solution will be the use of artificial wombs. In theory these can be made of any size, and will allow us even to breed elephants in Outer Space. However, currently is this technology not fully developed, so at this moment interspecific pregnancy is our best option. But if reproductive technology advances artificial wombs will provide us an ideal solution.

Some thoughts on terraforming

This post was originally published on blogspot.com on October 22, 2011

Terraforming is a recurring idea in both science fiction and real proposals for space colonization. In the latter it is often seen as a logical next step after initial settlements on other planets. Actually there are in space colonization theory two different approaches: 1. colonization of celestial bodies (moons, planets and so on) and 2. using space habitats (free-floating space stations intended for permanent settlements).

Terraforming is, of course, part of the first approach. For some reason approach 1 is the most dominant and best known version of space colonization in both science fiction and public knowledge. We of Republic of Lagrange are, however, supporters of approach 2, which we’ll discuss in an other post.

Terraforming is seen by some planetary chauvinists as the ultimate goal of space colonization. But we want to discuss some issues related to terraforming.

The most important problem of terraforming is the rather small amount of planets or other bodies in our solar system which can be terraformed. Actually only two bodies can be terraformed: Venus and Mars. All other proposed candidates for terraforming have too less mass, to maintain an atmosphere. Although the scientific study of terraforming started with Venus, most likely candidate for terraforming is Mars.

A problem with Mars, and to a lesser degree also with Venus, is that Mars is a lot smaller than Earth. Therefore Mars’ total surface area equals Earth’s total dry land area. Calculations show that if Mars is changed into a blue planet approximately half of its surface will be covered with a two kilometer deep ocean, and so reducing the potential area for settlements. If we use Earth’s current population density, this gave living space for some three billion people, that sounds a lot (and it is), but if future space civilization grows to a multiple tens of billions people, the combined surface area of Earth and Mars, whether or not terraformed, is much too less.

The same problem also goes up for Venus, although this planet has some ninety percent of Earth’s total surface area (both land and water). But in order to remove the thick and carbon-dioxide rich atmosphere, some propose to introduce large amounts of hydrogen into the Venusian atmosphere where it should react with CO2 to water and oxygen. However this would cause a Venusian ocean which covers eighty percent of the planet’s surface, with a depth of some hundred meters. A quick calculation the remaining surface will provide Lebensraum for some 4.7 billion people (assuming current terrestrial population density).

Our preliminary conclusion has to be that terraforming only offers a limited amount of land for space colonists. We have to terraform both planets in order to allow a doubling of Earth’s population (at current density).

But is far from the only problem of terraforming, in both cases the total costs will be enormous, Mars will probably be cheaper than Venus, since the former is easier to terraform. And in both cases it will take centuries before the process is completed.

So the question is whether we should go for terraforming Mars and Venus? Honestly, I think we shouldn’t. In each case we need to move vast amounts of resources through the solar system. We could make better use of those materials than for wasting them in terraforming. Free space habitats are cheaper, faster to realize and easier to move. And resources in the solar system allow space habitats to increase mankind’s living space with a factor thousand.

Why colonising the Sun-Earth Lagrange points?

This post was originally published on blogspot.com on June 6, 2012

In this post I will provide more clarity about our position that man should colonize the Lagrange points of the Earth-Sun system (in this post I simply use the term Lagrange point in order to refer to these).

In two earlier posts I discussed the arguments the colonization of the moon and Mars. Contrary to what most people tend to believe, many space colonization advocates do not support the colonization of these two particular objects. Why? First concern is gravity, in order to stay healthy people need gravity. And since we know that the Moon’s gravity is far too low, and that of Mars is also likely too low, it would be a better idea to use man-made structures, known as space habitats, which provide artificial gravity through rotation.

But gravity is not the only objection for the colonization of objects, one of the most important issues is natural resources. The Moon lacks many resources essential for life, especially hydrogen, carbon and nitrogen. The Near Earth Asteroids (NEAs), however, are expected to posses nearly all elements we need to maintain a high-tech civilization and also easier to reach in terms of energy consumption (for a more detailed discussion see here).

Energy consumption and energy efficiency are very important issues. Since the Lagrange points require less energy to reach than the Moon, it also mean that it would require less fuel to launch a space craft. Less fuel, means less costs. This also implies that returning valuable resources to Earth, will out compete lunar mining activities. Therefore an asteroidal colony has a greater economic viability than a lunar colony in the long run.

Another concern is less technical, but probably more important, is politics. Since the Moon is generally considered to belong to all humans, setting up a lunar colony and mining operations is very likely to become subject of much controversy. Although it’s technically true that this whole common heritage of mankind bullshit, also applies to asteroids, but I expect that most people will not get any strong feelings about a bunch of mere rocks.

Although most NEAs are not located at the Lagrange points, they can easily be reached from there. Further some planetary scientists that so-called Earth trojans might exist, until now the existence of only one such object has been confirmed, see here for more. Some space advocates propose bring NEAs into earth orbit. I don’t believe this will be a good idea, due to the increased risks an asteroid impact, but it could be a nice idea to bring some valuable asteroids to the Lagrange points, if there are no usable Earth trojans.

Although the Lagrange points are easier to reach in terms of energy consumption, the distance between them and the earth is still huge and as a result travel time is in the order of months instead of days in case of the Moon. This both an advantage as a disadvantage, the latter no need an explanation, but the former does. In case of a conflict with one of the major terrestrial powers, a sovereign moon colony will be an easy prey for a military intervention, while Lagrange point colonies are able to detect such mission months in advance and thus they will be able to act accordingly. Particle beam weapons will made it possible to destroy a hostile space craft within hours after detection, without the need of launching an interception missile. So we can conclude that colonies based at the Lagrange points can more easily obtain and maintain their political independence than any lunar colony.

Colonization of Mars

This post was originally published on blogspot.com on February 3, 2012

In this post I will discuss the pros and cons of the colonization of Mars.

The colonization of Mars is considered by some as the holy grail of human space exploration. Since the end of the second World War many plan for manned missions to Mars are proposed and also the possibility to establish permanent human settlements on the Red Planet is regularly discussed by Space enthusiasts.

Until the 1970s the Moon and Mars were the logical locations for the first human colonies in our Solar System. Because both celestial bodies are relatively easy to reach (a manned mission to other solar systems would take several thousands years with current technology). But at the end of the 1960s scientists like Gerard O’Neill started to explore the possibilities of free space habitats and their designs gave way to a new approach to Space colonization.

The main problem with the colonization of both the Moon as Mars, is the small gravitation of these bodies. Especially in case of the Moon, this would give serious problems for human health, however it is currently unknown of Mars’ gravity would be sufficient for humans. In space habitats the problem of low gravity is solved by centrifugation.

O’Neill e.a. proposed to use lunar and asteroidal resources to build space habitats. The advantage of this is that both the Moon as asteroids have a low escape velocity compared to Earth, while Mars’ escape velocity is roughly half Earth’s. This is one, among many others, reason why we of Republic of Lagrangia are in favor building space habitats in the Lagrange points of the Sun-Earth system.

Although manned Mars missions are a recurrent theme, no such mission has been undertaken. Main reason for this is (shortsighted) politics, not science and technology. Actually it is estimated that the US government has wasted a few times more money in Iraq and Afghanistan, than the price of a manned mission to our Red Neighbor.

But we have to ask ourselves if despite the abundant, and therefore cheap, recourses of the Near Earth Asteroids, there is potential for colonizing Mars. First I would say that regardless of any advantage of space habitats over Mars, there will be people who want to settle on the Red planet, simply because of planetary chauvinism. But there is a good reason for colonizing Mars, I will discuss them later in this post.

From a technical point of view colonization of Mars, is not that difficult (the biggest problem with any manned mission is the trip itself). Actually, one can argue that Mars is easier to settle than the Moon. As Zubrin argues in this article Mars possesses all the elements necessary for human civilization. Therefore Martian colonists will not dependent on importation from Earth as much as Lunar colonists.

Main problem with populating the Red planet, is establishing habitats in which people can function in a normal way. Well one can make domed cities by using Martian made glass or plastic. Another solution is building subsurface structures. In both cases the habitats will be filled with breathable air.

If we have livable habitats on Mars, than the next big problem is power supply. For the colonization of Mars there are essentially two sources of energy: nuclear and solar power. Since Mars is farther away from the sun, it reserves only 42 percent of the amount of solar as Earth.

Deposits with relatively high concentration of thorium and uranium should exist on Mars. These elements can be used for Martian fission reactors, further Zubrin states that the percentage of deuterium is five times higher than on Earth (mainly because deuterium is heavier than normal hydrogen, and therefore possesses a higher boiling point). This can be used as fuel for nuclear fusion reactors. Both fission and fusion power not only produce electricity, but also provide colonists with heath for their habitats.

Although Mars only receives half as much solar power than Earth, solar power is the most promising candidate for powering Martian colonies. Since our planet receives every hour more energy, than the annual global energy consumption, we can safely assume that solar power is able to provide enough energy for Mars.

By solar power most people will think of large parts of Mars covered with solar arrays, however it will be more efficient to build solar power satellites in orbit around Mars. In orbit SPSs will receive sun light nearly continuously and the can be made arbitrarily large. Further, by beaming the harvested energy through high intensity microwaves, less Martian surface is needed for power generation.

Since the escape velocity of Mars is roughly half Earth’s, it doesn’t make sense to build SPSs from Martian resources. In the 1970s it was proposed to construct SPSs for use in near earth space from lunar material, in order to circumvent high launching costs from Earth. Happily there several small bodies in near Mars space: first have the two moons of Mars, which are believed to be captured asteroids. And there are also Mars trojans, a family of asteroids orbiting the L4 and L5 points of Sun-Mars system.

The moons and trojans can not only provide resources for SPSs, but can also deliver huge amounts of volatiles for Martian and other Space colonists.

Despite the technical feasibility of the colonization of Mars, he have to ask why we should do it. In this article, Eric Drexler provide several arguments against the colonization of Mars. In essence the main contra argument is that Mars has a too high escape velocity to be competitive with asteroidal mining schemes. And since mining would be the prime motive for Martian settlement, this seems to be the end the Martian Dream. Due the relatively large travel time between Earth and Mars, tourism is unlikely to become a big drive settling the red planet. For the space tourist industry Lunar colonies are more attractive, since the Moon can be reached in just a few days.

However there is one reason for colonizing Mars worth to be considered, Zubrin argues that Mars could produce food for colonies in the Asteroid belt. Crops can easily be grown on the red planet. We have only the build greenhouses and launch sites. Question is whether this should be necessary. Assuming that the first settlers in the Asteroid belt are mainly involved in mining, they have to import their food. In order to launch food from Earth to the asteroid belt we need to overcome Earth’s gravity (escape velocity) and we need energy to change from the orbit of the Earth around the Sun to the Belt (delta V). For Mars both the escape velocity as the delta V are lower, so transporting food from Mars to the Belt consumes less energy and is therefore cheaper. However if we assume that before the Belt man will first colonize Near Earth asteroids, we have to consider the possibility of transporting food from them to the Belt. Well, free space habitats have zero escape velocity, while delta V is roughly the same as for transport from Earth.

Despite its technical feasibility, we of Republic of Lagrangia believe that colonizing our Red Neighbor should only happen, if ever, after the colonization of the Lagrange points of the Earth-Sun system.

Further reading:

http://www.nss.org/settlement/mars/zubrin-colonize.html

http://www.nss.org/settlement/L5news/1984-case.htm

For the establishment of secular, liberal, humanist and republican space settlements