The Case for Mars (37 page)

The advantage of the NIMF’s mode of operation are manifold. Despite its lower specific impulse, the fact that the NIMF does not have to carry its return propellant gives the vehicle complete global reach, while even the best chemical systems are range limited. The NIMF offers another advantage: because it makes its own propellant, it puts far less strain on the power resources of the base than the chemical systems. Producing the 60 tonnes of methane/oxygen required by the chemical rocket systems described at the beginning of this section would fully occupy a 100 kWe reactor stationed at the base for 123 days. An NIMF sortie would cost the base power supply nothing, nor would it tap into the base’s hydrogen or water supply. Its only imposition on the base would be for crew supplies, maintenance, and repair. Another benefit of having an NIMF operating on Mars is its unique ability to engage in rapid global surface-to-surface shipment of large quantities of cargo. If you need 20 tonnes of copper sulfide ore, a 40-tonne cargo NIMF could fly to the other side of the planet and get it for you. No other system can offer this kind of performance.

You may recall (Chapter 3) that in the period prior to the development of the Mars Direct mission architecture I had advocated a humans-to-Mars architecture based upon a single heavy-lift launch, nuclear thermal rocket (NTR) propulsion for trans-Mars injection, and the use of an NIMF vehicle to hop around Mars and then return. I dropped this in favor of Mars Direct because it became clear to me that the technology required for NTRs and NIMFs was too advanced to form the basis of initial Mars exploration missions. The missions they made possible were very attractive, but the schedule required for their development would postpone the first mission beyond the point of programmatic viability. That said, it remains the case that NIMF technology offers a set of extremely potent capabilities to support the development of the Mars base. Thus, in the context of an extended Mars program, it woud be wise to spend a significant effort to bring NIMF vehicles into play. Then, a few years into the base-building phase, they will be ready, and the base will be able to access resources from all over the planet.

THE BEGINNINGS OF COLONIZATION

The first astronaut explorers on Mars will spend an eighteen-month tour on the Red Planet, waiting for the first good launch window to open for their return. But as the base develops and living conditions improve, some future astronauts may choose to extend their surface stay beyond the basic one-and-a-half-year tour of duty, to four years, six years, and more. The base’s sponsors will probably offer large financial bonuses to those who choose to do so. After all, most of the expense of the base actually lies in moving people back and forth. The longer the base operates, the more incentive there will be to develop new forms of interplanetary transportation that reduce logistics costs ever lower. As we will see, the government may do this, or perhaps it will be done by opening base cargo deliveries from Earth to private competition, but it will be done. It will become ever cheaper to go to Mars, and ever cheaper to maintain people once they are there. As more people steadily arrive and stay longer before they leave, the population of the base will come to resemble a town—and will actually grow into one.

The colonization of Mars will then begin.

8: THE COLONIZATION OF MARS

This proposition being made publike and coming to the
scanning
of all, it raised many variable opinions amongst men, and caused many fears & doubts amongst themselves. Some, from their reasons & hops conceived, laboured to stirr up & incourage the rest to undertake and prosecute the same; others, againe, out of their fears, objected against it, & sought to diverte from it, aledging many things, and those neither unreasonable nor unprobable; as that it was a great designe, and subjecte to many unconceivable perills & dangers...

It was answered that all great & honourable actions are accompanied with great difficulties, and must be both enterprised and overcome with answerable courages.

—Gov. William Bradford,
Of Plimoth Plantation
, 1621.

In the previous chapters we have looked at the process of opening Mars to human settlement largely from a technical point of view. We have seen that using twentieth-century technology, the first human explorers can reach Mars in about ten years for a cost well within the discretionary spending capabilities of the U.S. government. We have seen that with a comparatively limited extension of this effort, a base can be built upon Mars capable of supporting dozens or even hundreds of people within
a few decades of the first landing—people who will then proceed to master the techniques of local resource utilization that could someday make Mars the home for millions.

We thus come to the crux of the matter: the settlement phase. Can Mars really be colonized? From the technical point of view, there is little doubt that we can eventually do just about anything we want on Mars, including, as we shall see in the next chapter, terraforming Mars—transforming the planet from a frigid, arid world into a warm, wet planet once again. But how much can we afford? While the exploration and base-building phases can and probably must be carried out on the basis of government funding, during the settlement phase econocs comes to the fore. While a Mars base of even a few hundred people can probably be supported out of pocket by governmental expenditures, a developing Martian society, one that may come to number in the hundreds of thousands, clearly cannot. To be viable, a real Martian civilization must be either completely autarkic (very unlikely until the far future) or be able to produce some kind of export that allows it to pay for the imports it requires.

Around this question will hang the future of Mars, and not just human civilization on Mars but the very nature of the planet itself. If a viable Martian civilization can be established, its population and powers to change the planet will continue to grow. Mars was once a temperate planet, and with enough work, it can be made so again. The advantages to Mars settlers of a terraformed world are so obvious, that put simply, if Mars is colonized, then it will also be terraformed. Therefore, ultimately, the feasibility or lack thereof of terraforming Mars is fundamentally a corollary to the economic viability of the Martian colonization effort.

Thus, the central objection raised against the human settlement and terraforming of Mars:
Such projects may be technologically feasible, but there is no possible way that they can be paid for
. On the surface, the arguments given supporting this position appear cogent, for Mars is a distant place, difficult to access, and possesses a hostile environment that holds no apparent resources of economic value. These arguments appear 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. It is certainly true that the technolo
gical and economic problems facing Mars colonization in the twenty-first century are vastly different in detail than those that had to be overcome in the colonization of the New World. Nevertheless, it is my contention that these arguments are flawed by essentially the same false logic and lack of understanding that resulted in repeated misevaluations of the value of colonial settlements (as opposed to trading posts, plantations, and other extractive activities) on the part of numerous European governments during the four hundred years following Columbus.

During the period of their global ascendancy, the Spanish ignored North America; to them it was nothing but a vast amount of worthless wilderness. In 1781, while Cornwallis was being blockaded into submission at Yorktown, the British deployed their fleet into the Caribbean to seize a few high-income sugar plantation islands from the French. In 1803, Napoleon Bonaparte sold a third of what is now the United States for two million dollars. In 1867, the Czar sold off Alaska for a similar pittance. The existence of Australia was known to Europe for two hundred years before the first colony arrived, yet no European power even bothered to claim the continent until 1830. These pieces of short-sighted statecraft are legendary today. Yet their consistency shows a persistent blind spot among policy-making groups as to the true sources of wealth and power. I believe that two hundred years from now the current apathy of governments toward the value of extraterrestrial bodies, and Mars in particular, will be viewed in a similar light.

It is almost impossible to know what enterprises will be economically viable twenty years from now, let alone fifty or one hundred. Nevertheless, in this chapter I shall endeavor to show you how and why the economics of Mars colonization can be made to work, and why the success of this colonization effort will ultimately be the keystone to human expansion throughout our planetary system. While I shall return to historical analogies periodically, my arguments will not be primarily historicalir cature. Rather, they are based on the concrete case of Mars itself, its unique characteristics, resources, technological requirements, and its relationships to the other important bodies within our solar system.

THE UNIQUENESS OF MARS

In proposing a new enterprise, for example in a business plan, it’s generally necessary to assemble and list the advantages of your product or service. What have you got that the competition doesn’t have? All right then, what’s Mars got?

Among extraterrestrial bodies in our solar system, Mars is singular in that it possesses all the raw materials required to support not only life, but a new branch of human civilization. This uniqueness is illustrated most clearly if we contrast Mars with the Earth’s Moon, the most frequently cited alternative location for extraterrestrial human colonization.

In contrast to the Moon, Mars is rich in carbon, nitrogen, hydrogen, and oxygen, all in biologically readily accessible forms such as carbon dioxide gas, nitrogen gas, and water ice and permafrost. Carbon, nitrogen, and hydrogen are only present on the Moon in parts-per-million quantities. Oxygen is abundant on the Moon, but only in tightly bound oxides such as silicon dioxide (SiO
₂
), ferrous oxide (Fe
₂
O
₃
), magnesium oxide (MgO), and alumina oxide (Al
₂
O
₃
), which require very high energy processes to reduce. Current knowledge indicates that if Mars were smooth and all its 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 could be grown in greenhouses on the Moon (an unlikely proposition, as we’ve seen) most of their biomass material would have to be imported.

The Moon is also deficient in about half the metals of interest to industrial society (copper, for example), as well as many other elements of interest such as sulfur and phosphorus. Mars has every required element in abundance. Moreover, on Mars, as on Earth, hydrologic and volcanic processes have occurred that are likely to have consolidated various elements into local concentrations of high-grade mineral ore. Indeed, the geologic history of Mars has been compared to that of Africa,
³⁶
with very optimistic inferences as to its mineral wealth implied as a corollary. In contrast, the Moon h
as had virtuall
y no history of water or volcanic action, with the result that it is basically composed of trash rocks with very little differentiation into ores that represent useful concentrations of anything interesting.

You can generate power on either the Moon or Mars with solar panels, and here the advantages of the Moon’s clearer skies and closer proximity to the Sun than Mars roughly balance the disadvantage of large energy storage requirements created by the Moon’s 28-day light/dark cycle. But if you wish to
manufacture
solar panels, so as to create a self-expanding power base, Mars holds an enormous advantage, as only Mars possesses the large supplies of carbon and hydrogen needed to produce the pure silicon required for producing photovoltaic panels and other electronics. In addition, Mars has the potential for wind-generated power while the Moon clearly does not. But both solar and wind power offer relatively modest potential—tens or at most hundreds of kilowatts here or there. To create a vibrant civilization you need a richer power base, and this Mars has both in the short and medium term in the form of its geothermal power resources whiittle differ potential for a large number of locally created electricity-generating stations in the 10 MWe (10,000 kilowatt) class. In the long term, Mars will enjoy a power-rich economy based upon exploitation of its large domestic resources of deuterium fuel for fusion reactors. Deuterium is five times more common on Mars than it is on Earth, and tens of thousands of times more common on Mars than on the Moon.

But, as we discussed in Chapter 7, the biggest problem with the Moon, as with all other airless planetary bodies and proposed artificial free-space colonies, is that sunlight is not available in a form useful for growing crops. A single acre of plants on Earth requires 4 MW of sunlight power, a square kilometer needs 1,000 MW The entire world put together does not produce enough electric power to illuminate the farms of the state of Rhode Island, that agricultural giant. Growing crops with electrically generated light is just economically hopeless. But you can’t use natural sunlight on the Moon or any other airless body in space unless you put walls on the greenhouse thick enough to shield out solar flares, a requirement that enormously increases the expense of creating crop land. Even if you did that, it wouldn’t do you any good on the Moon, because plants won’t grow in a light/da
rk cycle lasting 28 days.