Are We Going To Colonize Mars?
May 14, 2010 29 Comments
Probably you have seen little green and big headed aliens from planet Mars in Sci-Fi movies. Albeit I’m not going to talk about such stupid imaginary aliens. I’m going to examine whether colonization of Mars is probable. Mars has ever suggested as best candidate for space colonization among terrestrial planets.Mars has a thin atmosphere and has a low atmospheric pressure.
The atmosphere of Mars is relatively thin, and the atmospheric pressure on the surface varies from around 30 pascals (0.0044 psi) on Olympus Mons‘s peak to over 1,155 pascals (0.1675 psi) in the depths of Hellas Planitia, with a mean surface level pressure of 600 pascals (0.087 psi), compared to Earth’s 101.3 kilopascals (14.69 psi), and a total mass of 25 teratonnes, compared to Earth’s 5148 teratonnes. However, the scale height of the atmosphere is about 11 kilometers (6.8 mi), somewhat higher than Earth’s 7 kilometers (4.3 mi). The atmosphere on Mars contains traces of oxygen, water, and methane, for a mean molecular weight of 43.34 g/mole. The atmosphere is quite dusty, giving the Martian sky a light brown or orange color when seen from the surface; data from the Mars Exploration Rovers indicate that suspended dust particles within the atmosphere are roughly 1.5 micrometers across.It consists of 95% carbon dioxide, 3% nitrogen and 1.6% argon. There has recently been found traces of methane which is quite encouraging when thinking about the possibility of life.[ref:weirdwarp and wikipedia]
A frequent objection raised against scenarios for the human settlement and terraforming of Mars is that while such projects may be technologically feasible, there is no possible way that they can be paid for. On the surface, the arguments given supporting this position appear to many to be cogent, in that Mars is distant, difficult to access, possesses a hostile environment and has no apparent resources of economic value to export. These arguments appear to be ironclad, yet it must be pointed out that they were also presented in the past as convincing reasons for the utter impracticality of the European settlement of North America and Australia.
The exploration phase of Mars colonization has been going on for some time now with the telescopic and robotic surveys that have been and continue to be made. It will take a quantum leap, however, when actual human expeditions to the planet’s surface begin.If the Martian atmosphere is exploited for the purpose of manufacturing rocket fuel and oxygen, the mass, complexity, and overall logistics requirements of such missions can be reduced to the point where affordable human missions to Mars can be launched with present day technology. Moreover, by using such “Mars Direct” type approaches, human explorers can be on Mars within 10 years of program initiation, with total expenditure not more than 20% of NASA’s existing budget.
After exploration , we need to search the base where we will reside on. Then we can even think about terraforming Mars.If a viable Martian civilization can be established, its population and powers to change its planet will continue to grow. The advantages accruing to such a society of terraforming Mars into a more human-friendly environment are manifest4. Put simply, if enough people find a way to live and prosper on Mars there is no doubt but that sooner or later they will terraform the planet. The feasibility or lack thereof of terraforming Mars is thus in a sense a corollary to the economic viability of the Martian colonization effort. Green House gases would be best to increase temperature significantly. In a research it was shown that a rate of halocarbon production of about 1000 tonnes per hour would directly induce a temperature rise of about 10 K on Mars, and that the outgassing of CO2 caused by this direct forcing would likely raise the average temperature on Mars by 40 to 50 K, resulting in a Mars with a surface pressure over 200 mbar and seasonal incidence of liquid water in the warmest parts of the planet. Production of halocarbons at this rate would require an industrial establishment on Mars wielding about 5000 MW or power supported by a division of labor requiring at least (assuming optimistic application of robotics) 10,000 people. Such an operation would be enormous compared to our current space efforts, but very small compared to the overall human economic effort even at present. It is therefore anticipated that such efforts could commence as early as the mid 21st Century, with a substantial amount of the outgassing following on a time scale of a few decades. While humans could not breath the atmosphere of such a Mars, plants could, and under such conditions increasingly complex types of pioneering vegetation could be disseminated to create soil, oxygen, and ultimately the foundation for a thriving ecosphere on Mars. The presence of substantial pressure, even of an unbreathable atmosphere, would greatly benefit human settlers as only simple breathing gear and warm clothes (i.e. no spacesuits) would be required to operate in the open, and city-sized inflatable structures could be erected (since there would be no pressure differential with the outside world) that could house very large settlements in an open-air shirt-sleeve environment.
Nevertheless, Mars will not be considered fully terraformed until its air is breathable by humans. Assuming complete coverage of the planet with photosynthetic plants, it would take about a millennia to put the 120 mbar of oxygen in Mars’ atmosphere needed to support human respiration in the open. It is therefore anticipated that human terraformers would accelerate the oxygenation process by artificial technological approaches yet to be determined, with the two leading concepts being those based on either macroengineering (i.e. direct employment of very large scale energy systems such as terrawatt sized fusion reactors, huge space-based reflectors or lasers, etc.) or self reproducing machines, such as Turing machines or nanotechnology. Since such systems are well outside current engineering knowledge it is difficult to provide any useful estimate of how quickly they could complete the terraforming job. However in the case of self-replicating machines the ultimate source of power would be solar, and this provides the basis for an upper bound to system performance. Assuming the whole planet is covered with machines converting sunlight to electricity at 30% efficiency, and all this energy is applied to releasing oxygen from metallic oxides, a 120 mbar oxygen atmosphere could be created in about 30 years.
In contrast to the Moon, Mars is rich in carbon, nitrogen, hydrogen and oxygen, all in biologically readily accessible forms such as CO2 gas, nitrogen gas, and water ice and permafrost. Carbon, nitrogen, and hydrogen are only present on the Moon in parts per million quantities, much like gold in sea water. Oxygen is abundant on the Moon, but only in tightly bound oxides such as SiO2, Fe2O3, MgO, and Al2O3, which require very high energy processes to reduce. Current knowledge indicates that if Mars were smooth and all it’s ice and permafrost melted into liquid water, the entire planet would be covered with an ocean over 100 meters deep. This contrasts strongly with the Moon, which is so dry that if concrete were found there, Lunar colonists would mine it to get the water out. Thus, if plants were grown in greenhouses on the Moon most of their biomass material would have to be imported. But the biggest problem with the Moon, as with all other airless planetary bodies and proposed artificial free-space colonies (such as those proposed by Gerard O’Neill8) is that sunlight is not available in a form useful for growing crops. This is an extremely important point and it is not well understood. Plants require an enormous amount of energy for their growth, and it can only come from sunlight. For example a single square kilometer of cropland on Earth is illuminated with about 1000 MW of sunlight at noon; a power load equal to an American city of 1 million people. Put another way, the amount of power required to generate the sunlight falling on the tiny country of El Salvador exceeds the combined capacity of every power plant on Earth. Plants can stand a drop of perhaps a factor of 5 in their light intake compared to terrestrial norms and still grow, but the fact remains; the energetics of plant growth make it inconceivable to raise crops on any kind of meaningful scale with artificially generated light. That said, the problem with using the natural sunlight available on the Moon or in space is that it is unshielded by any atmosphere.
Mars, on the other hand, has an atmosphere of sufficient density to protect crops grown on the surface against solar flares. On Mars, even during the base building phase, large inflatable greenhouses made of transparent plastic protected by thin hard-plastic ultra-violet and abrasion resistant geodesic domes could be readily deployed, rapidly creating large domains for crop growth. Domes of this type up to 50 meters in diameter could be deployed on Mars that could contain the 5 psi atmosphere necessary to support humans. If made of high strength plastics such as Kevlar, such a dome could have a safety factor of 4 against burst and weigh only about 4 tonnes, with another 4 tonnes required for its unpressurized Plexiglas shield. In the early years of settlement, such domes could be imported pre-fabricated from Earth. Later on they could be manufactured on Mars, along with larger domes (with the mass of the pressurized dome increasing as the cube of its radius, and the mass of the unpressurized shield dome increasing as the square of the radius: 100 meter domes would mass 32 tonnes and need a 16 tonne Plexiglas shield, etc.). Networks of such 50 to 100 meter domes could rapidly be manufactured and deployed, opening up large areas of the surface to both shirtsleeve human habitation and agriculture. If agriculture only areas are desired, the domes could be made much bigger, as plants do not require more than about 1 psi atmospheric pressure. Once Mars has been partially terraformed however, with the creation of a thicker CO2 atmosphere via regolith outgassing, the habitation domes could be made virtually to any size, as they would not have to sustain a pressure differential between their interior and exterior.
Now other important prospect for colonization of Mars is Transportation of material. Here is table from research paper which shows it won’t be costly enough though.
To understand this, it is necessary to consider the energy relationships between the Earth, Moon, Mars, and the main asteroid belt. The asteroid belt enters into the picture here because it is known to contain vast supplies of very high grade metal ore10 in a low gravity environment that makes it comparatively easy to export to Earth. Miners operating in the main belt, for reasons given above, will be unable to produce their necessary supplies locally. There will thus be a need to export food and other necessary goods from either Earth or Mars to the main belt. As shown in the table below, Mars has an overwhelming positional advantage as a location from which to conduct such trade.
Table 1 Transportation in the Inner Solar System Earth Mars DV(km/s) Mass Ratio DV (km/s) Mass Ratio Surface to Low Orbit 9.0 11.4 4.0 2.9 Surface to Escape 12.0 25.6 5.5 4.4 Low Orbit to Lunar surface 6.0 5.1 5.4 4.3 Surface to Lunar Surface 15.0 57.6 9.4 12.5 Low Orbit to Ceres 9.6 13.4 4.9 3.8 Surface to Ceres 18.6 152.5 8.9 11.1 Ceres to Planet 4.8 3.7 2.7 2.1 NEP round-trip LO to Ceres 40.0 2.3 15.0 1.35 Chem to LO, NEP rt to Ceres 9/40 26.2 4/15 3.9
Nevertheless, the order of magnitude of the $320,000 fare cited for early immigrants-roughly the cost of a upper-middle class house in many parts of suburban America, or put another way, roughly the life’s savings of a successful middle class family – is interesting. It’s not a sum of money that anyone would spend lightly, but it is a sum of money that a large number of people could finance if they really wanted to do so. Why would they want to do so? Simply this, because of the small size of the Martian population and the large transport cost itself, it is certain that the cost of labor on Mars will be much greater than on Earth. Therefore wages will be much higher on Mars than on Earth; while $320,000 might be 6 year’s salary to an engineer on Earth, it would likely represent only 1 or 2 years’ salary on Mars. This wage differential, precisely analogous to the wage differential between Europe and America during most of the past 4 centuries, will make emigration to Mars both desirable and possible for the individual. From the 17th through 19th centuries the classic pattern was for a family in Europe to pool it’s resources to allow one of its members to emigrate to America. That emigrant, in turn, would proceed to earn enough money to bring the rest of the family over. Today, the same method of obtaining passage is used by Third World immigrants whose salaries in their native lands are dwarfed by current air-fares. Because the necessary income will be there to pay for the trip after it has been made, loans can even be taken out to finance the journey. It’s been done in the past, it’ll be done in the future.
In short, Martian civilization will be practical because it will have to be, just as 19th Century American civilization was, and this forced pragmatism will give it an enormous advantage in competing with the less stressed, and therefore more tradition bound society remaining behind on Earth. Necessity is the mother of invention; Mars will provide the cradle. A frontier society based on technological excellence and pragmatism, and populated by people self-selected for personal drive, will perforce be a hot-bed of invention, and these inventions will not only serve the needs of the Martians but of the terrestrial population as well. Therefore they will bring income to Mars (via terrestrial licensing) at the same time they disrupt the labor-rich terrestrial society’s inherent tendency towards stagnation. This process of rejuvenation, and not direct economic benefits via triangle-trade for main-belt asteroid mineral resources, will ultimately be the greatest benefit that the colonization of Mars will offer Earth, and it will be those terrestrial societies who have the closest social, cultural, linguistic, and economic links with the Martians who will benefit the most.
[ref: The Economic Viability Of Space Colonization by Robert Zubrin]