Tag Archives: space colonization

The first generation space habitats

Space colonization will be a process with multiple stages, on this site we usually discuss the latter stages of this process. However, it is important also to discuss the earlier stages. These earlier stages will be characterized by small human presence in space and extensive use of robotics and teleoperation.

As space colonization will develop, the number of humans is space will grow. Hence we distinguish between different generations of space settlements. The first generation of space habitats are dumbbells and similar designs. The second generation consists of Bernal spheres and toroidial designs. And the third generation consists of O’Neill cylinders.

The second and third generation of space habitats, as defined above, are large structures designed for large populations. The reason why these designs are large, is because they use centrifugation to replace gravity. The centrifugal force depends on the product of the radius and the angular velocity. A larger radius requires a lower angular velocity, which is preferred by most humans.

Both the Bernal sphere and the Stanford torus have a radius in the order of a few hundred meters, which implies about one revolution per minute. Their designs require a lot of material resources, however. On the other hand, these designs also provide living space for tens of thousand people.

First generation space habitats will also use centrifugation to replace gravity, but use a simpler design which would require less material. But consequently provide room for fewer people. Though this is not really an issue in the early stage of space colonization.

The dumbbell habitat design consists of two modules, with an equal mass, which are connected with each other with a tether. The structure rotates around its midpoint, halfway the tether, and hence generating a centrifugal force.

The tether can be of any desired length, while there no special size requirements for the two modules. Even if the tether is a few hundred meters long, the material requirements will be modest. The modules themselves are similar to those of the international space station, though we could also opt for the inflatable modules of Bigelow Aerospace.

A similar design is the bola space habitat.

Dumbbell habitats will serve as a first base for asteroid mining and the construction of next generation habitats. Depending on the size of the modules a few dozen people will stay at the habitat.



For those who do not believe in hell, I have bad news: you are dead wrong. At any given moment this place is located between 41 million and 258 million kilometres away from Earth. Temperature over there is 462 degrees Celsius and its atmosphere is filled with acid. We call this place Venus.

At first sight Venus does not seem to be an interesting place for space colonists. In this post I will discuss the value of the second planet for future space colonization.

One of the most remarkable features of our twin-sister planet, is her thick atmosphere, (yes, this deserves her very own Wikipedia lemma). Her atmosphere’s main component is carbon dioxide (96.5%), followed by nitrogen (3.5%) and traces of other compounds.  One of these other compounds is sulphuric acid. This mineral acid is very corrosive, but nevertheless it is used in many important industrial processes. Hence the mining of sulphuric acid is quite interesting for space settlers.

Mining sulphuric acid from the atmosphere of Venus is in many aspects quite similar to mining helium 3 from the outer planets. So Venus might be used as a training ground for helium mining on, say, Uranus. Technologies developed for this economic activity can be used in the Outer Solar System, with modest adaptations.

But also Venus’s large nitrogen reserves are quite interesting. Nitrogen is essential for terrestrial life, and it’s one of the basic ingredients of fertilizers. Through the Baber-Bosch process ammonia is produced from nitrogen and hydrogen. And ammonia has, besides the production of fertilizers, many industrial applications.

And what to think of the enormous amount of carbon dioxide on Venus? Carbon dioxide can directly be used for growing crops, which utilize photosynthesis to convert water and carbon dioxide into biomass and oxygen. But these carbon dioxide reserves could also be used to produce graphene and synthetic diamonds. These substances have interesting properties for use in electronics.

In order to produce either graphene or diamonds, one has to reduce carbon dioxide to pure carbon. One way to do this is the Bosch reaction. In this process we let carbon dioxide react with hydrogen gas, the end product is carbon and water. Hydrogen gas has to be imported from outside Venus, but the water can be dumped on Venus itself, since there’s more than enough water in outer space.

At 50 km above the surface of Venus both temperature and atmospheric pressure are similar to those at Earth at sea level. But since carbon dioxide is has higher density than breathable air, the latter would be a lifting gas at Venus. A balloon, also known as aerostats, filled with air would float in the atmosphere of Venus. We can use such aerostats as a platform for our mining operations, and even as the site for processing the collected gases.

Though Venus herself is not suitable for colonization, her atmosphere is full of valuable resources for space settlements and their inhabitants. The greatest challenge to any mining activity in the atmosphere of Venus, is her relatively high escape velocity, which is slightly less than Earth’s.

Penal transportation

Some criminals pose such a danger for society, that they need to be removed from society. By doing this citizens are protected from future crimes from said criminals. Such “punishments” are meant to deter or to rehabilitate criminals, the sole purpose of such treatment is incapacitation.

Nowadays prison sentences are often used to incapacitate dangerous criminals. In this post we will defend the “reintroduction” of the ancient penalty of penal transportation. First we will define penal transportation. Then we will analyse what kind of crimes should be punished by penal transportation. Thereafter we will discuss the practical aspects of this penalty.

What is penal transportation and what is the difference with prison? Penal transportation is the compulsory sending of people to a penal colony as punishment for a crime. Prison is any building used to lock people up as a punishment. In the case of penal transportation, the primary restriction is that the convicts remain in the colony. Further restrictions might be imposed upon them, but this not a prerequisite.

In our model the convicts are basically free to do whatever they want, except leaving the colony. Only communication with the outside world will be restricted, not to punish the convicts, but to protect civilized society from them.

This is a great difference with prison, where people are locked up in a small room for a large part of they day. We believe that long prison sentences are a kind of psychological torture, which only make people more dangerous than less.

Since incapacitation is the primary purpose of penal transportation, rather than rehabilitation, we should restrict this penalty to the really dangerous criminals, those who are likely to commit violent crimes again. Further this suggests that this penalty should be of indefinite duration. Under Napoleon’s Code Penal transportation was basically a life sentence, whilst under British law transportation was for time (although after completion this term, one had to pay for his own return).

An indefinite sentence means that the duration of the sentence is not predefined. In practise the actual time served depends on the prisoner’s own conduct. This allows the periodic re-evaluation of one’s sentence. Those criminals who remain a serious threat to society might remain in the penal colony for the remainder of their lives. A minimum term to be served of fifteen years, is in our opinion reasonable.

Peter Moskos suggests that pedophiles, psychopathic killers and terrorists should be locked up for life. We would add (serial) rapists and violent repeat offenders to his list.  These are the types of criminals for whom we believe, penal transportation is appropriate.

The idea of a penal colony is to relocate criminals to a remote place, in order to isolate them from society. The remoteness of the penal colony serves a protection measure in case a convict would escape from the colony. The greater the distance between the colony and society, the more difficult it will be for the fugitive to return to the country.

Any space habitat can serve as a penal colony, no one can escape with out a space ship. The suicidal nature of escaping of a space based penal colony will refrain convicts from attempting escape. However, some might manage to escape by stealing or hiding in visiting space ships. In that case long distances will also mean long travel time, and this will allow authorities to recapture the escapees before their effective return.

What should deportees do in such a space penal colony? Rather than to lock those convicts up in a small cell, they will be encouraged to perform labour. But unlike traditional labour camps, employment will and should be voluntary. However, taking up a job would increase the convict’s prospects of an early release. Besides employment, the prisoners will receive opportunities for education.

What kind of work will those convicts do? First, they have to be fed. Hence farming would be a major source of employment in penal colonies, as would be the processing of agricultural products. Mining would be another possibility, especially if these penal colonies are located in the Asteroid belt. But also some of the supervising of the prisoners could be done by convicts. Of course, the higher levels of supervision will be carried out by non-convicts. But convicts with demonstrated good behaviour could be rewarded with lower level supervision tasks.

The Dangers of Space colonization

Gerard O’Neill devoted a whole chapter in his The High Frontier, the space settler’s bible, to the dangers of space colonization. O’Neill addresses several dangers related to space colonization, but we will focus on what is probably the greatest danger of living in space: radiation. The facts are plain and simple: there’s a lot of radiation in space, and it’s bad for human health. more precise it’s lethal. Hence the question arise, can we protect ourselves against this space radiation? And how can we do this?

Without adequate protection against space radiation, space colonization will not be possible. Not only will radiation significantly reduce people’s lifespan, but it will also increase the number of mutations in the human genome. This might result in an increase of children born with genetic diseases.

Fortunately, we can protect people and space settlements from radiation. Late British engineer Paul Birch has proposed several methods to deal with this problem. These methods are: passive shielding, electro static and magnetic shielding. Either of these methods can be used alone, but combinations are possible.

The simplest method of protecting space settlements from space radiation is passive shielding. The idea behind this method is that radiation permeate badly through thick layers of matter. The thicker the layer, the less radiation will permeate through it. This method has, however, a major disadvantage: the shield needs to be very heavy. Birch has calculated that 42 tonne per person will be needed. Though this might not be a serious concern for a space settlement, which has a relatively slow speed, but for fast-moving space ships this will be a big issue.

The kinetic energy of an object depends on both its velocity and its mass. Basically kinetic energy is the energy needed to give an object with mass m a velocity v. Therefore the greater the mass of a space ship is, the more energy it will take to give it a certain velocity. Passive shielding is a solution for space settlements, but not for space ships.

A space based civilization cannot without inter-settlement shipments. And therefore Birch has proposed two other methods, the electrostatic and the magnetic shielding. Though the former method does lower the required mass needed for shielding, it’s still quiet high for a space ship and hence more suitable for larger structures such as settlements.

The magnetic shielding method only require 3.1 tonne per person. This method works exactly in the same way as the Earth’s magnetic field protects terrestrial life from space radiations, by deflecting it. An “artificial” magnetic field can be created by letting an electric current flow though a wire.

The main advantage of passive shielding to active shielding, is that it never fails. Further the shield can be incorporated into the structure of the settlement. On the other hand magnetic shielding is the only suitable solution for space ships. A combination of these three methods of shielding can be appropriate in specific situations.


Birch, Paul. Radiation Shields for Ships and Settlements. Journal of the British Interplanetary Society, Vol. 35, pp. 515-519, 1982.

How high can we build in a space habitat?

Living in a space habitat is quiet different from living on the surface of a planet. On Earth our head is oriented outwards, i.e. our head is pointed away from the centre of the Earth. But in a space habitat our head is oriented inwards, pointing towards the centre. Therefore we cannot build higher than the distance between the wall of the habitat and its centre, but this is not the only, or even most important, restriction for the height of building in space habitats.

In a space habitat gravity is replaced by the centrifugal force, which is generated by rotating the habit around its axis. This (virtual) force is given by the following equation: Fcent = m(w^2)r (I have used ‘w‘ instead of the small omega, since I don’t know how to type Greek letters in WordPress), with m the mass of the object on which the force acts, w the angular velocity of the habitat and r the distance between the object and the axis. On Earth gravity is given by the equation Fgrav = mg, with g the so-called gravitational acceleration, which is (on average) g = 9.81 m/s^2.

If we want that the centrifugal force acting on the inner wall of the space habitat (which we will refer to as “street level”), we have to solve Fcent = Fgrav. Or

m(w^2)r = mg

We see that we can cancel m on both sides of the equation, and write

(w^2)r = g = 9.81

Since r is in fact nothing else than the radius of our space habitat (which would be in case of an O’Neill cylinder be 3,000 meter), and hence a design parameter, we can only play with the habitat’s rotational speed in order to fix the strength of the centrifugal force.

A consequence of the last equation, the larger the radius of a space habitat how smaller its angular velocity will be. But also that by a given w, the closer you are to the axis of rotation, the smaller the centrifugal force acting on you will be. At the axis of rotation the centrifugal force is zero.

The whole point of substituting gravity with centrifugation is to counteract the health effects of low or zero-gravity. Therefore the height of a building will be restricted by the minimum accepted level of gravity. Recall that in a space habitat we are building towards the axis. So the question of height becomes a question of what is the accepted minimum gravity?

Gerard O’Neill have suggested that 70 % of Earth’s gravity, or 0.7g is an acceptable minimum level of gravity. Our equations show that for a given space habitat the strength of the centrifugal force is linearly dependent of the distance to the axis of rotation. Hence 0.7g is present at 0.7r, or at 0.3r if we are counting from street level. Assuming r = 3,000m than we can erect building up to 900m (counted from street level).

Participatory budgets

In previous posts we have discussed how the governments of space settlements can raise money and how they can avoid to borrow money. We will summarize the key points of these post: 1. Since governments are the owners of space habitats, they can use the collection of land rents to fund government expenditure, hence all other taxes can be abolished. 2. Because the government of a space settlement can require that land rent has to be paid in government issued money, it creates an effective demand for national currency and gives value to this money.

By playing with the height of (the total sum of) land rents (R), and the height of public expenditure (S), the government can control to growth of the money supply. This because the change of the money supply (delta M) is simply: delta M = S – R. In this way, governments of space settlements can control the level of inflation. Because this system is vulnerable for abuse by politicians seeking electoral gains, we have proposed to establish an independent body which will set the height of land rent, and the level of government spending. How the government would spend this money will remain a political issue.

The authority to prove the government budget is among the most important powers modern parliaments have. Without an approved budget, a government can’t function since they can’t pay its bills. In modern democracies the influence of citizens on the budget is limited to their ability to participate in voting for the legislature.

Attempts to increase citizen participation in budgetary matters, haven’t been successful. The most simplest version, the government just proposes a budget, which is subsequently subjected to a referendum. Then the citizens can either vote for or against the proposed budget. The result is quite predictable: since any given budget would contain measures a particular citizen does not agree with, many people will simply vote against the budget. Hence there will be no approved budget, and even if the government would submit a modified budget to a popular vote, there will be no guarantee the citizens will approve it this time.

A more extreme, and even more dysfunctional, example of budgeting by referendum is California. As a result of a series of initiatives the Californian state budget is fixed for a substantial portion. Such initiatives have form of “Do you agree that the government should spend 30% of its budget to education?”, on which the citizens can only vote “yes” or “no”. And whatever the majority wants, will be done. The result is that some government programs are over-funded, while others are underfunded. Another problem which might arise is an inconsistent budget, i.e. a budget which spends more than 100% of the budget.

Often this example is used by opponents of direct democracy to “prove” that direct democracy does not work.  However, the problem here is not (direct) democracy as such, but the “dogma” that a budget has to be approved by a majority of the voters. It’s taken for granted that if the government would want to spend one million MU on public parks, this should be approved by a majority of voters, even if this is a majority of one vote.

This majoritarian thinking has several problems. First, it forces the minority to spend its money on things they do not want. Secondly, a complex compromise has to be found, since money spent on A cannot be spent on B. It’s this second issue what goes wrong when you attempt to make a budget by referendum, millions of citizens cannot negotiate a budgetary compromise.

The whole concept of a non-majoritarian budget seems strange and democratic, but I will give you a non-budgetary example. A few years ago I heard on the radio the story of a father and daughter who had written a crime novel together, and how did they do this? Well, first the father wrote a chapter, than his daughter the next one taking her father’s contribution into account, then the father wrote the third chapter and so on. The father and his daughter did not vote, nor were they seeking a compromise on each chapter. And still they managed to finish the novel together.

Can we conceive a similar approach for participatory budgets? Yes, it can and several proposals have been made. One idea is known as “tax choice“, in this concept each tax payer determines how his or her tax money will be spent by checking the appropriate boxes on his tax form. This approach has two problems: it requires to have an income tax, the very thing we wants to avoid in a space settlement. And secondly it gives more power to those who pay more tax, and thereby violating the “one man-one vote” principle. A slightly different version has been proposed by Mark Rosenfelder.

The version of participatory budgets we propose is as follows. Each year each adult citizens receive a form from the national budget office. On this form the citizens can distribute, say, 10,000 MU among different government programs. One can spend all money on the military or distribute it evenly among education, science, healthcare, arts and infrastructure or some other combination. By filling in this form, he or she has only to consider his or her own preferences. After filling this form, it’s returned to the national budget office, which collect all these forms of the whole citizenry.

In this proposal every one has an equal vote on the budget, which follows from the arguments discussed in “The problem of taxation. Part Two“. Since land should be a collective property, the revenues from land rents should be enjoyed by all in an equal fashion. Hence it is justified that all citizens should have an equal say into the budget.

The next question is whether the entire budget should be determined in this way? No, we believe that a fifty-fifty split between the citizens and the legislature would be appropriate. It’s important that the state has some discretionary spending power, for example to act in an emergency.

Why should we consider participatory budgets at all? Because it enhances the concept of self-governing citizens, the core of classical republicanism. As we said above, the most important power of modern governments is the power to spend money. Participatory budgets gave citizens a real stake in the governance of their nation, state or city, and create also a sense of responsibility among the citizens.

Space settlements and food security

Food security is defined by Wikipedia as “the availability of food and one’s access to it”. Usually we speak about individuals when we talk on food security, but we can easily extend this concept to societies at large. A society enjoys food security if there is enough food available for its members, and they have access to this food.

A society has two ways to ensure that the supply of food is sufficient: by producing its own food, or by importing such food. Once enough food is available, ensuring that each member of society has access to sufficient food is the big concern. The implementation of an adequate basic income guarantee will provide everyone with the means to buy food. Hence the sole concern would be availability of sufficient amount of food.

Related to food security is the concept of food power, which is the use of food as a mean to exert power. If country A depends on the import of food from country B, the latter country can exert power on country A by denying supply if A does not meet certain conditions establish by B. These condition might be unfavourable to A, and hence this country looses sovereignty.

Space settlements has to choose between producing or importing food.  If the latter option is chosen, the space settlements became vulnerable to the exertion of food power by Earth. In this way terrestrial governments might force space settlements to implement policies, which are in violation of their own preferences. If, however, the former option is chosen, a powerful weapon is denied to terrestrial governments to influence the (domestic) policies of space settlements.

If we want to implement the social reforms we desire in space settlements, such as our proposals for monetary and banking reform, it’s of great importance that these settlements have a certain degree of independence. Therefore space settlements should be able to produce their own food. In another post we will discuss how space settlements can grow food.

See also

Space settlements and vegetarianism

Molecular farming and Space colonization

Sleeper ships

A few weeks ago we discussed the desirability of embryo space colonization as mean for establishing interstellar space travel. In that post we argued such program would not have any purpose for this and the next few generations, and its only reasonable aim is to ensure the continuation of our species in the event that human life in our Solar System would become impossible.

Another popular suggestion for interstellar travel, and possibly colonization, is the use of so-called sleeper ships. In such ship the passengers are kept in suspended animation, a kind of artificial hibernation. Suspended animation should be distinguished from cryonics, the supposed science of freezing human corpses in the hope that future generations will be able to revive them. Though both concepts are often confused, the primary difference between those two are that in the former process the body’s metabolism is slowed down, but not terminated. In the latter process there’s no whatsoever metabolism present.

There are several technological issues with sleeper ships which has to be resolved before such ship could be launched. With the current state of affairs humans and other animals can be held into suspended animation for several hours or in some cases even days. Since interstellar space travel might take several decades to several thousands years, huge improvements in this field of science need to be made.

A related issue is that slowing down one’s metabolism might extend one’s life, but not necessarily long enough to arrive at the desired destination. And further even a suspended animated body still requires life support, which needs to last for many hundreds of years because repairs are not possible during the trip.

By travelling at relativistic speeds, one could take advantage of time dilation, the phenomenon that time will run slower if you are travelling faster. An interstellar journey might look from the perspective of an Earth bound observer a 1,000 years, but (depending on the actual speed) might be only a few decades for the passengers. This has clear benefits for the designers of the ship’s life support system, they only have to make sure their product will last for several decades instead of a 1,000 years.

Like embryo space colonization one should ask what purpose sending sleeper ships to distant star systems would serve, assuming the technical issues can be solved. Since an interstellar mission might take several centuries from our terrestrial perspective, current generations and those following immediately after us may not receive any benefit from such mission. And possibly humanity might not even exists in this part of the universe by then.

Therefore the main reason for the use of sleeper ships is for the sake of the passengers, as they are the only ones who will live long enough to witness the completion of the journey. But as a formal objective of public policy of interstellar space colonization, does not make much sense, unless we use it to transport all of humanity to an interstellar destination, or at least of all humans who are willing to emigrate to such destination.

Of course groups of selfish people might decide that they want to board a sleeper ship, maybe are these the same people as preppers, who will do anything to survive upcoming disasters. But these people shouldn’t count on public funding for their emigration plans. However, these are also the people for who sleeper ships are actually a solution.

Sleeper ships are currently not feasible, and offer also no clear benefits for the majority of currently living humans. The colonization of our own Solar System is feasible within a few decades from now, and can produce benefits for those who will remain on Earth. As a method of interstellar space colonization it’s only of interest for a small number of people.

Republic of Lagrangia and the Voyager

Those who think that Republic of Lagrangia is a space blog, might wonder why we didn’t pay attention to last week’s news that Voyager 1 has definitely left our Solar System. But those make a mistake: namely that we are a space blog. Only the fact is that Republic of Lagrangia is not a space blog, we are a blog about space colonization.

One might argue that the topic space colonization is a subset of the topic space. Though this is technically true,  categorizing Republic of Lagrangia as a space blog might however create the confusion that we are a generic space blog, what we are not. Suppose that Alice has a blog about horses, than we might say that Alice has a blog about animals. In this case it’s obvious that doing so is absurd, since Alice only writes about a specific type of animals.

Since we are not a generic space blog, calling Republic of Lagrangia a space blog is equally absurd as calling Alice’s blog an animal blog. Most space blogs are about space exploration, and should better be called space exploration blogs.

Space exploration, the scientific study of the universe, is without doubt a fascinating topic to write about. It’s only of limited relevance for space colonization. The major arena for space colonization in the near future, is the Inner Solar System. Therefore discoveries made about distant galaxies, or even our own galaxy is of little importance for the colonization of our own neighbourhood.

It’s for us more interesting to discuss the developments in other areas of science and technology, such as 3D-printers or in vitro meat, which might help the colonization of outer space.

And more importantly, we of Republic of Lagrangia see space colonization as a mean to implementing social reforms, rather as an end in itself. We belief that it’s important to give space colonization an appeal beyond the circle of space geeks. Therefore we focus on the social issues of space colonization, and if we discuss scientific or technological developments, we focus on how these developments might affect society.

Therefore we did not write about Voyager 1 leaving our Solar System.

Developments in Solar energy technology

The whole idea of space colonization is founded on two facts: the abundance of extraterrestrial mineral resources and the availability of huge amounts of cheap Solar energy. There are basically two approaches to harvest Solar energy for space settlements: photovoltaic cells and solar-thermal power plants. The latter uses the heat from our Sun to heat a fluid, which is used to drive a turbine.

A challenge for photovoltaic arrays, is their efficiency. But there is exciting news from this field, according to The Science Daily, scientists from North Carolina State University have designed a method to increase solar array efficiency up to 45%. This would mean less Solar cells are needed to produce energy.