Talk:Equipment for autonomous growth

Open Issue: "abstain from any electronics"

• Is it possible to abstain from any electronics on Mars? This is an essential question as it may decide about the technological long term stability of a Martian colony.

• I'm not even sure what the question means, can you please elaborate? Peter 20:17, 25 November 2007 (UTC)

• I think what is meant (Rfc, correct me if I'm wrong) is that is it possible for colonists to live in an established colony (I can't even remotely see how this is possible for early settlements) with the bare minimal of electronics (apart from life-support systems I assume) - a minimalist existence (akin to "Areophany" as established by the character Hiroko in the novel Red Mars)? -- Ioneill 22:08, 25 November 2007 (UTC)

Please let me explain a little. What mean is not to abstain from any automation on Mars, only abstain from electronics. The things we are used to do with electronics are not really bound to the flow of electrons and the creation of semiconductors. Moreover, you can do automation with exactly the same functionality and precision by means of pneumatics for example. I have learned this during my apprenticeship many years ago. We have constructed complex circuits with flowing air instead of flowing electrons. This technology seems to be almost forgotten, and people tend to think of electronics as the only way of doing automation. Here on Earth it is easy to go to the electronics merchant and buy a handful of transistors and rectifiers. But on Mars? I am afraid the settlers can not afford to build a transistor factory with all the costly technology required for making a transistor out of sand. May be it will be possible some day, but perhaps not now. This applies consequently for silicon based solar panels, also. And it might be hard to maintain a communication link between Mars and Earth, for it might be impossible to build an electronic radio transmitter. Sure, we will use electronics during the initial installation of the first settlement, but this is not what I mean with this open issue. Instead, I mean the autonomous growth afterwards.

What I intend with this open issue is to pose this problem and to make people think about possible alternatives. May be it is possible to build a transistor factory on Mars, may be it is not. In the latter case we need an alternative, or else we have no autonomous settlement. -- Rfc 08:31, 26 November 2007 (UTC)

Computer power is increasing exponentially, so I don't think it makes sense to build heavy and complex air based "computers". A computer the size of a cellphone at the time when Mars is being colonized will be as fast as todays supercomputers.. At first most computers will be transported from Earth, but at some point they will be fabricated on Mars. Obviously, complex technology like this will be the last things to be fabricated on Mars. However, computers are really lightweight, so I don't see this as a problem. Nawi 11:53, 1 July 2008 (UTC)

The weight is not the point. The effort for reproduction is the point. A Martian colony is not autonomous if reproduction of such a computer is not possible. -- Rfc 20:06, 2 July 2008 (UTC)

A martian colony does not have to 100% autonomous from the start. Using air pipes etc for automation would make a really inefficient and bad Martian colony. Nawi 11:10, 3 July 2008 (UTC)

Pneumatic data processing is used on Earth where the interface between pneumatic and electronic systems would be an added complication, and the needed data processing is simple enough. Data processing is used wastefully on Earth because megaflops are cheap. If only the necessary data processing for automation is done, pneumatic, hydraulic, or other fluidic data processing is an alternative. - Farred 15:59, 9 November 2012 (UTC)

Even if the goal is only economic rather than complete physical self-sufficiency -- and commerce won't invest in it without economic self-sufficiency plus profit -- and even if there are many lucrative exports, we will still have strong incentives to achieve almost complete physical self-sufficiency, to minimize the mass of imports from Earth. It costs over $100,000/kg to get stuff to the Martian surface from Earth. That cost has not fallen very much since the Viking lander in 1976. Even with two orders of magnitude reduction in cost by the time we start the colony, it will still cost a dollar a gram to import anything from Earth, and it will all have to be paid for by exports. So sure, we can have sophisticated electronics -- but they will be confined to gram-sized chips and sensors and wireless connections and software. We have to interface these Earth chips with crude machines made by craftsmen using other crude machines, which may lack any other kinds of electronics whatsoever. Making equipment in a tiny economy, rather than in Earth's global economy with its billions of diverse workers who make billions of different kinds of sophisticated parts, requires a radical redesign of every single piece of equipment. Frontiersman 13:54, 12 February 2010 (UTC)

vacuum tube technology could be produced on Mars and is an option to consider. There have been considerable inovations in vacuum tube technology such as carbon nanotube cold cathode diodes. Carbon nanotubes for this purpose could be produced as soot is produced. It might be suitabel for Mars.--Farred 00:18, 15 February 2010 (UTC)

I think that's a good idea, a good direction to explore, but be sure to account for all the different materials used in a vacuum tube.Frontiersman 01:46, 15 February 2010 (UTC)

Shared components

Is it posible to have all infrastructure on Mars constructed out of shared components? For example, uniform sizes of nuts, bolts, ball bearing, etc. This would eliminate overcomplexity in factories. Systems inside factries could use these componoents, a factory could "reproduce" if automated. Transistiors and other computer "hardware" equipment could be created using something like a 3-d printer, all that would differ would be the software. This allows a base to grow along with its population. T.Neo 11:35, 1 July 2008 (UTC)

Great idea! Go write it:-) -- Rfc

Re: Example: Repair of solar panels

An alternative to solar panels is solar thermal electric generation. The mirrors would need to be designed to withstand Martian wind storms, which are another aspect of the dust storms, or be sheltered during a storm. The steam condensing coils would be more difficult to cool in the thin atmosphere. However, there is a dependable low atmospheric temperature, so a big chimney might provide enough draft, something like a cooling tower for a nuclear power plant on Earth.

The months long dust storms would be a problem that would require some sort of power storage to meet the reduced power requirements for waiting out the storm.

The many things that a self reproducing colony ought to do would affect the minimum size of a self reproducing colony. I am nowhere close to putting a number on that size.

On the road to a self reproducing colony, an imported nuclear power plant could fulfill power needs. The plan for the self reproducing colony should be in hand when the first colonist sets out from Earth. Then regular colonist transportation would be needed until the planned size is fulfilled. - Farred 15:46, 9 November 2012 (UTC)

Solar thermal electric generation: Fascinating idea! We should write an article about it. Could be less prone to degradation due to cosmic radiation and UV.

Energy storage: There is an article about this already (energy storage).

Nuclear power: I don't like the idea, because the radioactive waste disposal is an unresolved problem as yet. This is true for both Earth and Mars. I better like the plan of Mars One, that provides all needed power from thin-film photovoltaic modules, which seems to be possible right from the start. -- Rfc 16:31, 9 November 2012 (UTC)

I would like to write an article on solar thermal electric generation myself, I can add it to my list. Like a number of articles on my list it would take considerable work including library research that I do only with difficulty. Instead I do things that are easy and consume my time, like removing spam and writing easy comments on talk pages. The spam is a discouraging waste of time, truly a plague on Lunarpedia.

I do not see any problem with disposing of nuclear waste on Mars. On Earth there is concern that leaking containers could contaminate ground water. On Mars people would need to look hard to find a place where there is ground water to contaminate. Probably there is some wet water under the polar ice caps where it was melted by planetary heat and slowly flows to the edge where it reaches the surface and evaporates and freezes. Any other place a pit could be dug and spent fuel elements laid in it. Cover them with a couple meters of regolith, concrete and a warning notice and they will harmlessly stay there for a thousand years. What is the problem? After a hundred years the radioactivity will have decreased enough to make reprocessing for new fuel rods relatively easy. A full uranium mining and enrichment industry is unneeded. You advocate solar power which is very expensive. It seems to me the problem is emotional, fear that is not based upon fact. If contributors to Marspedia mostly want nuclear power ruled out, it is the prerogative of the majority to have its way. - Farred 13:57, 13 November 2012 (UTC)

Certainly mistakes in engineering which allow accidents to cause nuclear contamination problems are a serious concern, but less so on Mars then on Earth. The habitat should be protected from nuclear contamination. The outside is full of radiation naturally from cosmic rays, the solar wind and coronal mass ejections. A nuclear leak to the outside would seem minor. To worry about the possibility of a nuclear accident on Mars and calmly accept the constant ambient radiation threat seems to me like straining out the gnat and swallowing the camel. - Farred 14:14, 13 November 2012 (UTC)

My idea of the best sort of power generation from the start of the colony on Mars to a period of steady expansion is in a number of steps. First use solar power and batteries. Next assemble a nuclear reactor with mostly local materials but fuel rods and other critical parts sent from Earth. The nuclear power will serve for periods without sunshine relegating energy storage to emergency use status. It would serve when nuclear power would be off line. Reducing the need for energy storage would make expansion of the electrical power system cheaper, so the colony as a whole could expand faster than otherwise. When the fuel rods reach maximum design burn up, they would be stored as I stated above. Replacement fuel rods would be sent from earth. This is a greater energy density in the mass transported than solar cells. After many years of colony growth and a few sets of fuel rod replacements, Mars would begin to reprocess old fuel rods for new, getting much more energy out of the fuel rods than is possible without reprocessing. The use of nuclear power for times without sunshine could increase as the size of the colony increases. It seems to me that if people put too many restrictions on how industry on Mars can develop, the development might become practically impossible and that time when industry can be devoted to terraforming will never be reached. I can not prove that this is so, but there are certainly difficulties in developing an electrical power system for a vast industry on Mars. There is no oxygen atmosphere in which to burn things like coal, and likely no coal. An ambitious goal of expanding a Mars colony requires some plan for a source of energy. Without such a plan, a Mars colony would be constantly small and dependant upon Earth. Terraforming would never be an option.

I am in a peculiar position on this wiki as a member of the Moon Society and not the Mars Society I would like to see a Mars colony progressing on a plan which is sufficient that it succeed in the long term but my viewpoint is different is some respects from members of the Mars Society in general. As a guest administrator, I would not want to oppose members of the Mars Society in anything I would put into an article. - Farred 00:44, 16 November 2012 (UTC)

The difficulty with the plan of Mars One is that it lacks any details as to when or how the colony will be self sufficient or expand. It seems to be based upon the assumption that no plan is necessary because the requirements are so simple that we can work out the problems once we have people on Mars. I disagree. I quote myself: "The plan for the self reproducing colony should be in hand when the first colonist sets out from Earth." The economics of a self reproducing colony on Mars is an extremely complex thing to be worked out in advance so that mistakes are not made in establishing industries in an inefficient order or having a Mars colony unnecessarily dependent upon Earth for a significant time. - Farred 08:22, 16 November 2012 (UTC)

Mars One seems to be working on plans. I thought the plans that I had seen previously were too sketchy to settle upon a date for sending the first manned mission to Mars. Recently I read what Mars One wrote about: "What’s keeping us busy?" First on the list was: "Preparations for the Conceptual Design Studies". It might have been better to have conceptual design studies before setting a date for landing men on Mars, but better late than never. The schedule might need to be delayed as they find out how difficult a problem they are facing. - Farred 09:17, 16 November 2012 (UTC)

I disagree about the cost of nuclear energy. The assumption that nuclear energy is cheaper than solar energy is simply wrong. And again, this is true for both Earth and Mars. I had a look at some interesting figures about research, development, safety and maintenance costs as well as subsidy facts of several sorts of energy, including fossil, nuclear and renewable energy. The result was that nuclear energy is by far the most expensive energy. If you had added all those expenses to the consumer price you are paying per kWh, you would pay nearly 2 USD per kWh. And this does not even include the cost for the final disposal. I am afraid, the nuclear power advocacy group is not really interested in spreading the truth about those costs. In contrast, the R&D costs for solar, wind, biomass etc. energy has been only a tenth. 20 cents per kWh is now a reality, with a strong tendency to drop further.

You may argue that the nuclear technology is now available and established, so no further investment may be necessary for research and development. This might be true if the colony was on Earth. The Martian conditions, however, require different colling systems, different logistics, different housings, different heat flow processes. And the most important difference is the size. While nuclear power plants on Earth are big and heavy (with big and heavy critical components), the plant for a 10000 person settlement would be rather small. The bigger the plant is, the more efficient it works with regards to the costs. Simple economics. It just does not scale down linear.

By the way, can you imagine the protests from the terrestrial people if the nuclear fuel rods are launched for transport to Mars? They will argue that the rocket may explode and contaminate Earth's atmosphere.

All these thoughts come to me, when I start thinking of powering a Martian colony with nuclear energy. I have no intention of retarding the Martian development due to some diffuse fear. I think that nuclear energy is not viable because of unagitated calculation.

Sure, energy is a critical issue for expansion of the colony. It certainly sets a limit. May be, someday the use of nuclear energy will be cheap and safe, thanks to some future inventions. The settlers may decide for themselves.

Any idea, even nuclear, is welcome on Marspedia, for my understanding. I see Marspedia as a collection of facts and ideas. It would be wrong to draw a lopsided picture of a Martian colonization. Several concepts may (and should!) be outlined. Only, each outline should be realistic and described with full range considerations. After all, I don't see much difference between Mars and Moon regarding energy.

And yes, I see a lack of concepts for further development in Mars One, too. Mars One seems to plan the initial installation with pure non-autonomous technology. I was somehow irritated in the first moment. But then it occurred to me that this is the fastest way of establishing a Martian settlement, thus being the only realistic way of starting. No matter what comes after that, the first step is done, and as soon as there are people on Mars, they will stay there by all means. This is because it will always be cheaper to keep them alive over there than to bring them back to Earth. The human genius will then, step by step, aim to make the Martian settlement more and more self sufficient. There is a lot hope in it, of course. -- Rfc 19:58, 18 November 2012 (UTC)

I am pleased to see you respond to my comments. My response in turn is waiting on my looking up something. I really do intend to comment further. - Farred 03:08, 22 November 2012 (UTC)

Take your time. By the way, have you seen [http:\\marsonefans.com]? -- Rfc 19:30, 22 November 2012 (UTC)

I have looked at power purchase agreements for solar power and they look like a scam to me. A person agrees to buy the electrical power produced by the solar cells on his house roof which are installed there at no up-front cost. The cost of purchasing the solar power according to contract is the only cost. This looks like a poor deal to me since the home owner is agreeing to buy power whether the power is used or not. The usual rate for power sold where I live is about $0.10 (ten cents) per kilowatt hour. This includes the cost of the generating plant equipment, distribution, billing, and wasted power which the power company must produce to keep the power available for peak demand without excessive fluctuations while people constantly turn power off and on. The cost of coal to produce electrical power is about four tenths to eight tenths of a cent per kilowatt-hour.(Richard A. Muller in PHYSICS FOR FUTURE PRESIDENTS, (C) 2008, W. W. Norton & Company in New York and London, page 75) When the generation, distribution and billing costs are added in, it is 10 cents per kilowatt-hour.(as above, page 83) If one made an agreement with the power company similar to the solar power purchase agreement, as some commercial users do, agreeing to buy a steady thousand kilowatts constantly whether it is used or not, then the power company could give a much better rate. Agree to interruptible power and get a better rate yet. I have seen my own bills for electricity from a utility that uses coal, gas, and nuclear generation of electricity. They come with a flyer that says that I can agree to purchase wind and solar power from the utility and they will charge me at a higher rate. This is the power company's way of complying with a legislative mandate to produce power from wind and solar sources and pass the cost along to customers that are willing to bear it. I do not assume that wind and solar cost more. These are real world costs. Wind and solar power cost more than other electricity produced by the power company. Solar power produced at a plant near Seville, Spain costs about 28 cents per kilowatt-hour.(as above, page 83) The legislative mandates to produce solar power in Spain and where I live are examples of subsidy of solar power. Nuclear power received a subsidy in the form of government financed research that developed the technology. Power companies are now paying for the costs of fuel and power plants for nuclear power. Avoiding use of the developed technology would not eliminate the development costs that have already been paid. It is solar and not nuclear power that is benefiting from current subsidies. What reference says anything different? The people selling solar power purchase agreements have an incentive to mislead people about costs until they have signed an agreement. Then the venders make it clear the agreement means the signer must pay. Who is supplying the claims of subsidy for nuclear power?

There are hundreds of millions of people in the United States living in households where the power is paid for without protesting the use of nuclear power to generate some of the power on the grid. A tiny group of anti-nuclear fanatics is willing to raise a ruckus and be arrested for interfering with various nuclear related activities. This did not prevent the Curiosity rover from being launched with a Radioisotope Thermoelectric Generator.

The waste disposal problem is not solved for nuclear power because people make emotional rather than rational decisions about the safety of nuclear waste disposal. There does not need to be an absolute certainty that absolutely no nuclear waste will leak from a disposal site for a thousand years. In three hundred years the radioactivity of spent fuel is reduced ninety percent.(as above, page 175) However, if the proposed Yucca Mountain disposal site were filled with the full 77,000 tons of high level waste that it was designed to hold and if 100% of the nuclear waste leaked the day that it was stored, it would cause only one twentieth of the radioactive contamination that comes from the uranium naturally in the soil of the state of Colorado.(as above, page176) Certainly there is danger in the concentrated radioactivity of the high level waste, but people exaggerating the problem are more of a problem than the waste itself. Certainly the possibility of a small radioactive leak on Mars is not much to worry about compared to the constant radioactivity on the surface. The entire atmosphere of Mars is equivalent to about a 27 centimeter thick layer of water as shielding, which is something, but not enough.

Nuclear Power on Mars would be different from on Earth because there is no need for a steel reinforced concrete containment building to surround the reactor. There is no biosphere to protect on Mars. In case of a catastrophic failure, a cloud of radioactive gas could disperse without making the ambient area more or less deadly to human beings. People would merely need to keep their distance from the hot fuel rods.

Nuclear power does not scale linearly in cost per kilowatt-hour but a small nuclear power plant is being considered for a lunar base. A similar power plant would probably work for Mars. However, if you are serious about a growing colony on Mars, a large plant should be built. What really does not scale is a human based economy. People need agriculture. On Earth the wild ecosystem recycles water and air. Sunlight is naturally available in the right quantity. Temperatures suitable for local crops recur in yearly cycles. On Mars artificial systems will need to recycle water and air. Sunlight would need to be artificially channeled to crops or artificial light provided. Temperature and humidity would need to be artificially maintained within limits. This means that the amount of industry needed to support each person on Mars is much more than the amount needed on Earth. Simple hand-craft industries will not do for the majority of the work. Most of it will need to be highly automated. That means big systems will be more efficient. A Mars colonization project should look at hundreds of colonists not a score of colonists. The problem of a partially closed regenerative life support system as necessary on Mars has not been solved. It should be demonstrated on Earth before the first colonist departs Earth. The ratio of industrial machinery to colonist must be much larger than the minimum ratio of industrial machinery to person on Earth.

As a Moon Society member I have a peculiar viewpoint. I appreciate the ability of Luna to host devices tele-operated from Earth to build up the industrial necessities for greenhouse agriculture and life support before people arrive. That might be possible for Mars too, but it would require further advances in artificial intelligence for robots to operate constructively for perhaps eight hours at a time without renewed instructions and still follow their general plan almost as surely as ants in a colony follow their general plan without constantly renewed instructions. A robot that reached a situation not covered by programming might need to just wait until an operator could review its problem and give it new instructions, or the robot could move on to a different task until it is told how to proceed on the first task.

You suggest that the fastest way of establishing a colony is the only realistic way of starting. I see no logical reason for that being the case. If the fastest way of establishing a colony results in a colony that fails, it is not a realistic way of starting. I am hard to convince. I want to see the details of how a colony will self reproduce, not just some vague hope that human genius will step by step make the settlement more self sufficient. The possibility of a colony perpetually dependant upon Earth is quite real to me. If the problem of growth with very small input from Earth is not solved, I do not see the value of the colony. - Farred 08:54, 30 November 2012 (UTC)

I was a little carried away in polemics. I should correct a couple of points. I do not know of any current subsidy of the production of nuclear power, but there are still government funds expended in developing nuclear technology for future use. One new technology is called a small modular reactor. This development is apparently paid for by General Atomics, but I am not certain of the source of funds. It looks like a good candidate for use on Mars. A growing colony should be able to use 240 Megawatts.

Agriculture on Mars should certainly be highly automated, but that could be done with few people. Workers on Earth could even help look after some operations that do not need time critical oversight. What causes difficulty are tasks that cannot be automated: surgery, dentistry, child care, child education. Maybe we could get a growing colony with less than a hundred colonists. People could master more than one specialty. It seems to me that there would likely be difficulties. If a colony were otherwise capable of growth with only thirty colonists, there would still be a dependence on immigration from earth until the genetic diversity of the colony was stable against debilitating genetic disease from recessive genes that could be expressed in later generations.

As to the funding, I do not expect Mars One to get enough to launch the first supply mission to mars. However, if they do, I still would worry about the continuity of funding through the point of a mostly self-sufficient growing colony. Depending on popular good will for advertising revenues seems risky to me. Tastes change. Three Stooges type comedy is only a small niche market now. Still if enough people are willing to go ahead and take the risks, Mars One's plans could go forward. - Farred 21:30, 1 December 2012 (UTC)

Above I referred to "constant radioactivity" on the surface of Mars. I should have written constant radiation, which is a different thing. I do not know how much induced radioactivity there is on the surface of Mars from its being exposed to cosmic radiation, but the principle problem from cosmic rays and the sun is the radiation. Leaks from nuclear reactors leave radioactivity which is a source of radiation which can be moved about, even ingested so as to be a source of radiation within one's body. Nuclear materials must be handled carefully.

A slow way of starting a colony on Mars would be to start remote controlled economic industry on Earth's moon first. This industry could cheaply ship into cis-lunar space the material for building large well shielded spacecraft that could cycle between Earth and Mars. Orbiting solar power plants designed for use at Mars could also be built from lunar material. Such things could be built from the resources in Phobos and Deimos, but the technology for tele-operation of industry on Luna has been demonstrated in concept. To start such industry on Phobos and Deimos would require more development or human colonists from the start, which would be a liability. That is the one point that it seems Mars Settlement enthusiasts are most likely to ignore. People in the early stages of a settlement are a major liability to the necessary development of industry. No matter how helpful it might be to have people to do work, it is certain that supporting them on Luna or Mars with resources on Earth is expensive. - Farred 18:44, 5 December 2012 (UTC)

Sorry for not answering so long. It is a whole lot to digest for me. We are already going into detail. There are a few things I agree with you:

• I worry about the continuity of funding.
• I want to see the details of how a colony will self reproduce.
• Nuclear materials must be handled carefully.
• The genetic diversity must be addressed.
• People must master more than one specialty.

But there are a few things I disagree:

• The amount of industry needed to support each person on Mars can not be more than the amount needed on Earth. The amount of industry on Earth is not as it is because it is enough to make a living. It is because this is the limit that can be afforded. People in third world countries can afford much less than U.S. or European people. That is why they have less industry. Not because the environmental conditions for their agriculture are better. So, the Martian settlers also have some limits. They have manpower, giving them the ability to afford something. I do not see, why they should be able to afford much more industry. I am afraid, they can afford less, because the conditions for agriculture are harder. Industry is not something that, once established, remains there and yields a continuous wealth. It must be maintained, and this is the cost that limits the amount. I think, the Martian settlement is more of a rural structure with low-tech processes, at least for the first century. This seems to me the only viable structure. The number of processes, materials, spare parts etc. must be limited to the affordability of the settlers with their limited manpower. Highly automated agriculture seems out of reach for now and is not a necessity.
• A slow way to build an extraterrestrial settlement will not work by all means, because it is by far more expensive, takes decades before the goal is reached, will see obsolescence of nearly all parts of the technology. Who shall give the money for it? A handfull of space colonization enthusiasts can definitely not pay it all. I am afraid the next decades on Earth will see some environmental and economic challenges, that might draw attention even farther away from manned space flight projects than now. And this increases my worries about the continuity of funding. So, if the settlement starts, it needs to be self sufficient quickly.
• Immigration from earth is not the only means against inbreeding depression. Shipping fertilized human eggs is the easiest way to solve the problem.

As I already stated on my user page, I never rely on some future technology, because this would be merely science fiction. It is not that I don't like SF, but I am sure the colonization of Mars is possible with current technology (which is one of the keystones of Mars One), and that makes it a project for reality. The possibility of enough funding for Mars One is a kind of self fulfilling prophesy. If many people think it will be a success, the funding will work, and it will be a success. If many people think the project will fail due to a lack of funding, the project will fail due to a lack of funding. So, If you want the space colonization to be a success, you should be optimistic rather than pessimistic about a quick success. Most people don't like projects that take too long. -- Rfc 21:45, 13 December 2012 (UTC)

• I think we agree that a self sufficient human settlement on Mars would be a good thing. The current knowledge of physics, chemistry, and biology is sufficient for such a settlement, but the technology of a partially closed greenhouse agriculture and life support system is not fully developed. It has been worked out in theory, not in practice. You write: "The amount of industry needed to support each person on Mars can not be more than the amount needed on Earth." This is simply false. On Mars greenhouses in pressure vessels holding one atmosphere pressure are needed for agriculture. This is not needed on Earth and is part of the necessary industrial infrastructure for a Mars settlement. A Mars settlement needs mining equipment to get water in the form of ice and process it. On Earth water is pumped out of rivers and wells and simply falls as rain on fields. The temperature and humidity controls needed in a Mars greenhouse are also added industrial requirements. All of the needed industrial infrastructure is wealth. A Mars settlement must be wealthy or die. You write: "Who shall give the money for it?" If sufficient money comes from reality T.V. then that pays for it. If there is no source of money for the needed industry to live on Mars, it is murder to send people to Mars without it.

• You write: "Industry is not something that, once established, remains there and yields a continuous wealth." This is false. The difference between the amount of industry that can be afforded by the average citizen of an industrially developed country today and the average European citizen in the year 1500 AD is a result of the industry there is to produce wealth. Industry includes not only the machines but the educational system that produces workers able to maintain them. For the work of operating and maintaining industrial systems today the average worker produces much more wealth per man-hour than the average worker in 1500 AD. That is the result of established industry yielding continuous wealth.

• Wealth includes not only production but also consumption. If there were no one to drive the many automobiles produced, they would be only so many hunks of rusting scrap. An apple tree in your yard produces wealth if you want to eat the apples and bake them into apple cake. If you do not consider the apples worth picking, if they are many more apples than you can use, then they become just a rotten mess on the ground that must be cleaned out of the way. More wealth must be produced in a Mars settlement than the minimum required on Earth because more wealth is needed to survive on Mars, so more wealth would be consumed.

• As for "Who shall give the money for it?" concerning a lunar industry, the buyers of electrical power generated in space and beamed to Earth would pay for it. This does not currently work as an investment plan because of the long development time needed before any profits are made. If the plan did work with the current level of technical development, industrial organizations would be establishing industry on the moon now. Future development for motives outside the purely financial are possible.

• You write: "I never rely on some future technology," and that is good for evaluating the potential for establishing a settlement on Mars with current technology. However, we are not guaranteed that current technology is sufficient. Napoleon looked at digging a tunnel under the English channel, but soon determined that it could not be done quickly enough to help with his war. There were numerous typewriters patented before one became a commercial success. The French started digging a panama canal before completing a plan by which it could be economically done. In all of these cases the plans and technical development necessary for a project were insufficient and the project had to wait until later developments made the project practical. The fact that you insult future technology on you user page by referring to it as "magic" is not a convincing argument that future technical developments will not be necessary for a colony on Mars. People should not be optimistic or pessimistic about plans to colonize Mars but rather realistic. There have been too many projects based more on optimism than pragmatism that have failed and used up peoples willingness to believe that a technologically based project will succeed. There has been X-33, MDX, Roton, and the Space Shuttle to name a few. The worst was the Space Shuttle because it came so close to working that the program just kept on using up tax money for years while program managers pretended that it was an economic space launch system or would become economic soon. I am an old man and have had enough of excessive optimism. It gives space industrialization a bad name. A project takes however long it takes. If there is nothing one can do to make it practical within the next twenty years, one can plan what will be needed in the future and hope or just forget it. - Farred 03:05, 20 December 2012 (UTC)