The Case for Mars (2 page)

In fact, as this book goes to press, NASA scientists have announced a startling discovery revealing strong circumstantial evidence of past microbial life within Antarctic rock samples that had previously been ejected from Mars by meteoric impact. The evidence includes complex organic mecules, magnetite, and other typical bacterial mineralogical residues, and ovoid structures consistent with bacterial forms. NASA calls this evidence compelling but not conclusive. If it is the remains of life, it may well be evidence of only the most modest representatives of an ancient Martian biosphere, whose more interesting and complex manifestations are still preserved in fossil beds on Mars. To find them though, it will take more than robotic eyes and remote control. To find them, we’ll need human hands and human eyes roving the Red Planet.

WHY MARS?

The question of taking on Mars as an interplanetary goal is not simply one of aerospace accomplishment, but one of reaffirming the pioneering character of our society. Unique among the extraterrestrial bodies of our solar system, Mars is endowed with all the resources needed to support not only life but the actual development of a technological civilization. In contrast to the comparative desert of the Earth’s moon, Mars possesses veritable oceans of water frozen into its soil as permafrost, as well as vast quantities of carbon, nitrogen, hydrogen, and oxygen, all in forms readily accessible to those inventive enough to use them. These four elements are not only the basis of food and water, but of plastics, wood, paper, clothing, and—most importantly—rocket fuel. Additionally, Mars has experienced the same sorts of volcanic and hydrologic processes that produced a multitude of mineral ores on Earth. Virtually every element of significant interest to industry is known to exist on the Red Planet. While no liquid water exists on the surface, below ground is a different matter, and there is every reason to believe that geothermal heat sources could be maintaining hot liquid reservoirs beneath the Martian surface today. Such hydrothermal reservoirs may be refuges in which microbial survivors of ancient Martian life continue to persist; they would also represent oases providing abundant water supplies and geothermal power to future human pioneers. With its twenty-four-hour day-night cycle and an atmosphere thick enough to shield its surface against solar flares, Mars is the only extraterrestrial planet that will accommodate large-scale greenhouses lit by natural sunlight. Even at this early date in its exploration, Mars is already known to possess a vital resource that could someday represent a commercial export. Deuterium, the heavy isotope of hydrogen currently valued at $10,000 per kilogram, is five times more common on Mars than it is on Earth.

Mars can be settled. For our generation and many that will follow, Mars is the New World.

GOING NATIVE: THE FAST TRACK TO MARS

Down through history, it has generally been the case that those explorers and settlers who took the trouble to study, learn, and adopt the survival and travel methods of wilderness natives succeeded where others did not. The foreigner sees wilderness where the native sees home—it is no surprise that indigenous peoples possess the best knowledge of how to recognize and use resources present in the wilderness environment.

To the eye of the urban dweller, an Arctic landscape is desolate, resourceless, and impassable. Yet, to the Eskimo it is rich. Thus, during the nineteenth century, the British Navy sent flotillas of steam-powered warships, at great expense, to explore the Canadian Arctic for the Northwest Passage. Loaded with coal and supplies, these expeditions would battle forward against the ice packs for several years at a time, until shortages would force an about-face or even cause the entire crew to perish.

At the same time, however, small teams of explorers working for fur trapping interests were traveling freely over the Arctic by dog sled. Adopting the methods of the natives, they fed themselves and their dog teams on local game and traveled light. At insignificant expense they accomplished far more in the way of exploration than did the naval fleets.

There is a lesson in all of this for space exploration. There are no Martians, yet. But if there are to be, let us ask ourselves some questions. How will they travel? Will they import their rocket fuel from Earth? How about their oxygen? Where will their water come from, their food? How will they survive? There can only be one answer:
When on Mars, do as the Martians will do.

TO MARS VIA DOG SLED

Many of the concepts advanced for piloted Mars missions have been analogous to the ponderous Royal Navy approach to the Arctic cited above. According to these plans, grand ships are required to haul out to Mars all the supplies and propellant required for the entire mission. Because such ships are too large to be launched in one piece, construction on orbit is required, as is long-term orbital storage of super-cold (or “cryogenic”) propellant. Large orbiting facilities are required to enable both of these operations. The cost of such a project soon goes out of sight. One such plan, known as the “90-Day Report,” developed in response to President Bush’s 1989 call for a Space Exploration Initiative, resulted in a cost estimate of $450 billion. The resulting sticker shock in Congress doomed Bush’s program and has deterred most people from seriously considering a humans-to-Mars program ever since.

However, as in the case of Arctic exploration, there is a different way a Mars mission can be approached—a “dog sled” way if you will. By making intelligent use of the resources available in the environment to be explored, this approach allows the logistical requirements for launching the mission to be reduced to the point where the endeavor becomes practical.

This is the spirit of “Mars Direct,” a new approach to Mars exploration that I introduced in 1990 while a senior engineer for the Martin Marietta Astronautics company, working as one of its leaders in development of advanced concepts for interplanetary missions. This plan employs no immense interplanetary spaceships, and thus requires neither orbiting space bases nor storage facilities. Instead, a crew and their habitat are sent directly to Mars by the upper stage of the same booster rocket that lifts them to Earth orbit, in just the same way as the Apollo missions and all unmanned interplanetary probes launched to date have flown. Flying the mission this way radically simplifies and scales down the required hardware, and eliminates the need for decades of development and hundreds of billions of dollars of expenditure on orbital assembly infrastructure. The key to this plan is the mission’s ability to use Mars-native resources to make its return propellant and much of its consumables on the surface of the planet itself.

It is the richness of Mars that makes the Red Planet not only desirable, but attainable.

A piloted Mars mission is not about building enormous interplanetary cruisers—it’s about moving a payload capable of supporting a small crew of astronauts from the surface of Earth to the surface of Mars, and then moving that or a similar payload back again to return the crew. Provided we take full advantage of the leverage afforded by the use of local resources to reduce mission logistics to a manageable level, such a task is not at all beyond our technical or fiscal means. Travel light and live off the land—that’s the ticket to Mars.

THE GROWTH OF A NEW IDEA

The Mars Direct plan, including its development and mission philosophy, its hardware components and overall architecture, its key operations and logistics requirements, backup plans and abort options, and, finally, its evolutionary potential will be described in this book. In 1990, when I and my key collaborator in its development, David Baker, first put the plan forward, it was viewed as too radical for many in NASA to consider seriously. Some did, however, and over time, through a process of patient explaining and refutation of the alternatives, I managed to gain a significant base of support. Many other people started to pitch in, and with their help the concept moved steadily up the decision-maker ladder. In 1992, I was invited to brief then-NASA associate administrator for exploration Dr. Mike Griffin, who immediately decided to lend his considerable support. Griffin then briefed incoming NASA administrator Dan Goldin, who also became an advocate, going so far as to discuss the plan at several of the “town meetings” NASA held as part of its public outreach during 1992 and 1993.

With the support of Griffin and Goldin, I was able to return to NASA’s Johnson Space Center and convince the group in charge of designing human Mars missions to take a good hard look at the plan. They produced a detailed study of a Design Reference Mission based on Mars Direct, but scaled up by nearly a factor of two in expedition size compared to the original concept. They then produced a cost estimate for a Mars exploration program based upon this expanded version of Mars Direct. Their estimate: $50 billion for all the required hardware development and flying three complete missions to Mars. The same costing group had assigned a $450 billion price tag to the traditional cumbersome approach to human Mars exploration embodied in NASA’s “90-Day Report.” In my opinion, if the JSC Design Reference Mission had been disciplined through the elimination of excess hardware and crew, the cost would have been cut in half—to something in the $20 to $30 billion range.

The Johnson Space Center team also gave Martin Marietta a small amount of money—$47,000 to be exact—to demonstrate what I had claimed was a simple chemical engineering technology for transforming the Martian atmosphere into rocket propellant. We did so, building in the course of three months a full-scale unit that operated at 94 percent efficiency. The demonstration was all the more convincing given that neither I, the project’s lead engineer, nor anyone else on the team was actually a chemical engineer by training. If we could build such a machine, then it couldn’t be that hard.

WE CAN DO IT

Twenty to thirty billion dollars is not cheap, but it’s roughly in the same range as a single major military procurement for a new weapons system; it’s in the same range as the money the United States government gave to Mexico in one afternoon in the summer of 1995. Spread over twenty years, with the first ten years developing hardware and the next ten years flying missions, it would represent between 8 percent and 12 percent of the existing NASA budget. For the sake of opening a new world to human civilization, it’s a sum that this country can easily afford.

Exploring Mars requires no miraculous new technologies, no orbiting spaceports, no anti-matter propulsion systems or gigantic interplanetary cruisers. We can establish our first outpost on Mars within a decade, using well-demonstrated techniques of brass-tacks engineering backed up by our pioneer forebears’ common sense.

How we can do it, and why we should do it, is the dual subject of this book.

ABOUT THIS BOOK

This book presents a condensation, in layman’s terms, of many years of technical work devoted to the development of practical plans for the human exploration of Mars. Although, as might be imagined, the details of human Mars mission plans are highly technical in nature, the core issues which determine the fundamental feasibility of such ventures really are not. Rather, they are questions of strategy that can be fully understood by anyone willing to do some clear thinking and who is equipped with some good basic information.

Unfortunately, such information has not been readily available to the public to date. The existing general interest science literature on piloted Mars missions is mostly rather nebulous or naive, while the technical literature is confused, obscure, and frequently distorted by the bias of various technical organizations using the medium of technical publications to argue for their own self-interest. For the educated layman, there really hasn’t been a satisfactory book on the subject. In part,
The Case for Mars
is an effort to correct this problem.

I have attempted to walk a fine line between technical detail and simple narrative description in this book. It is simple enough to declare one mission design superior to another, but it is also slightly disingenuous, as it is in the technical details that the reader will find the strongest arguments for or against any mission or technology. Some chapters are more technical than others (
Chapter 4
, which describes Mars Direct in detail, and
Chapter 5
, which exposes various arguments against piloted Mars missions for the hobgoblin myths they are, come to mind), but all should be understandable by both novice and expert alike. If for whatever reason you tend to pale before the nitty-gritty of numbers, just read on—you’ll get the drift well enough.

I’m an astronautical engineer, but earlier in my career I was a science teacher, and I strive to write and explain technical material in a clear, concise manner. I hold it as a fundamental tenet that (contrary to the witticism popular among some of my scientific colleagues) Clarity is not the enemy of Truth, but her most vital ally. Moreover, I feel very strongly that something as exciting and vital to the human future as the real issues involved in opening a new planet to humanity should not be the property of a technical elite, but must be open to consideration by everybody. Therefore, in writing this book I decided to enlist as a supporting author my long-time friend Richard Wagner, who as former editor of
Ad Astra
, the general interest space exploration magazine published by the National Space Society, has had years of experience bringing scientific arguments to the public at large. With his help, and that of Mitch Horowitz, our capable editor at The Free Press, I believe
The Case for Mars
may well prove successful in finally making the real issues of human Mars exploration comprehensible for the general reader.

Because ultimately it’s your understanding that’s going to get us to Mars.