The Case for Mars Read online

  To Maggie, Eliot, Sarah, and Rachel:

  my family, friends, and hope for the future.

  TOUCHSTONE

  Rockefeller Center

  1230 Avenue of the Americas

  New York, NY 10020

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  Copyright © 1996 by Robert Zubrin

  All rights reserved, including the right of reproduction in whole or in part in any form.

  First Touchstone Edition 1997

  TOUCHSTONE and colophon are trademarks of Simon & Schuster Inc.

  Designed by Carla Bolte

  Manufactured in the United States of America

  10 9

  Library of Congress Cataloging-in-Publication Data

  Zubrin, Robert.

  The case for Mars: the plan to settle the red planet and why we must / Robert M.

  Zubrin with Richard Wagner..

  p. cm.

  Includes bibliographical references.

  ISBN 0-684-82757-3

  1. Mars (Planet) 2. Life on other planets. I. Wagner, Richard (Richard S.), 1953–

  II. Title.

  QB641. Z83 1996

  919.9'2304—dc20

  96–26560

  CIP

  ISBN 0-684-83550-9 (Pbk)

  eISBN 978-1-4391-3521-1

  Henceforth I spread confident wings to space

  I fear no barrier of crystal or of glass;

  I cleave the heavens and soar to the infinite.

  And while I rise from my own globe to others

  And penetrate even further through the eternal field,

  That which others saw from afar, I leave far behind me.

  —Giordano Bruno

  “On the Infinite Universe and Worlds,” 1584

  CONTENTS

  Foreword by Arthur C. Clarke

  Preface

  1 Mars Direct

  2 From Kepler to the Space Age

  3 Finding a Plan

  4 Getting There

  5 Killing the Dragons, Avoiding the Sirens

  6 Exploring Mars

  7 Building the Base on Mars

  8 The Colonization of Mars

  9 Terrraforming Mars

  10 The View from Earth

  Epilogue: The Significance of the Martian Frontier

  Special Addendum

  Glossary

  Notes

  References

  Index

  FOREWORD

  The planet Mars is where the action will be in the next century. It is the only world in the solar system on which there is a strong probability of finding Life Past, and perhaps even Life Present. Also, we can reach it—and survive on it—with technologies which are available today, or which we can acquire in the very near future.

  Robert Zubrin’s book—which is often very amusing and contains asides which will not endear him to NASA—is the most comprehensive account of the past and future of Mars that I have ever encountered. It explains why we should go there, how we may go there—and, perhaps most important of all, how we may “live on the land” when we get there.

  Personally, I am delighted to think that—if Dr. Zubrin’s persuasive arguments are accepted—the first expedition to Mars may leave shortly before my ninetieth birthday. Meanwhile, if all goes well, the Russian Mars Lander will be leaving just before my seventy-eighth, carrying a message I have videod for the colonists of the next century:

  MESSAGE TO MARS

  My name is Arthur Clarke, and I am speaking to you from the island of Sri Lanka, once known as Ceylon, in the Indian Ocean, Planet Earth. It is early spring in the year 1993, but this message is intended for the future. I am addressing men and women—perhaps some of you already born—who will listen to these words when they are living on Mars.

  As we approach the new millennium, there is great interest in the et which may be the first real home for mankind beyond the mother world. During my lifetime, I have been lucky enough to see our knowledge of Mars advance from almost complete ignorance—worse than that, misleading fantasy—to a real understanding of its geography and climate. Certainly we are still very ignorant in many areas, and lack knowledge which you take for granted. But now we have accurate maps of your wonderful world, and can imagine how it might be modified—terraformed—to make it nearer to the heart’s desire. Perhaps you are already engaged upon that centuries-long process.

  There is a link between Mars and my present home, which I used in what will probably be my last novel, The Hammer of God. At the beginning of this century, an amateur astronomer named Percy Molesworth was living here in Ceylon. He spent much time observing Mars, and now there is a huge crater, 175 kilometers wide, named after him in your southern hemisphere. In my book I’ve imagined how a New Martian astronomer might one day look back at his ancestral world, to try and see the little island from which Molesworth—and I—often gazed up at your planet.

  There was a time, soon after the first landing on the Moon in 1969, when we were optimistic enough to imagine that we might have reached Mars by the 1990s. In another of my stories, I described a survivor of the first ill-fated expedition, watching the Earth in transit across the face of the Sun on May 11—1984! Well, there was no one on Mars then to watch that event—but it will happen again on November 10, 2084. By that time I hope that many eyes will be looking back towards the Earth as it slowly crosses the solar disk, looking like a tiny, perfectly circular sunspot. And I’ve suggested that we should signal to you then with powerful lasers, so that you will see a star beaming a message to you from the very face of the sun.

  I too salute to you across the gulfs of space—as I send my greetings and good wishes from the closing decade of the century in which mankind first became a space-faring species, and set forth on a journey that can never end, so long as the universe endures.

  Doubtless in many of its details, Dr. Zubrin’s book—like my own exercise in terraforming Mars, The Snows of Olympus—will be bypassed by future advances in technology. However, it demonstrates beyond all reasonable doubt that the first self-sustaining human colony beyond Mother Earth lies within the grasp of our children.

  Will they seize the opportunity? It is almost fifty years since I ended my first book, Interplanetary Flight, with these words:

  The choice, as Wells once said, is the Universe—or nothing. . . . The challenge of the great spaces between the worlds is a stupendous one; but if we fail to meet it, the story of our race will be drawing to its close. Humanity will have turned its back upon the still untrodden heights and will be descending again the long slope that stretches, across a thousand million years of time, down to the shores of the primeval sea.

  Arthur C. Clarke

  1 March 1996

  PREFACE

  We choose to go to the Moon! We choose to go to the Moon in this decade and do the other things, not because they are easy but because they are hard, because that goal will serve to organize and measure he best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win. . . . This is in some measures an act of faith and vision, for we do not know what benefits await us. . . . But space is there and we are going to climb it.

  —John F. Kennedy, 1962

  The time has come for America to set itself a bold new goal in space. The recent celebrations of the twenty-fifth anniversary of the Apollo Moon landings have reminded us of what we as nation once accomplished, and by so doing have put the question to us: Are we still a nation of pioneers? Do we choose to make the efforts required to continue as the vanguard of human progress, a people of the future, or will we allow ourselves to be a people of the past, one whose accomplishments are celebrated only in museums? When the fiftieth anniver
sary arrives, will our posterity honor it as the touchstone of a frontier pushing tradition that they continue? Or will they look upon it much as a seventh century Roman may have once gazed upon the aqueducts and other magnificent feats of classical architecture still visible among the ruins, saying to himself in amazement, “We once built that?”

  There can be no progress without a goal. The American space program, begun so brilliantly with Apollo and its associated programs, has spent most of the subsequent twenty years floundering without direction. We need a central overriding purpose to drive our space program forward. At this point in history, that focus can only be the human exploration and settlement of Mars.

  Mars is the fourth planet from the Sun, about 50 percent farther out than Earth, making it a colder place than our home planet. While daytime temperatures on Mars sometimes get up to 17° centigrade (about 63° Fahrenheit), at night the thermometer drops to -90°C (-130°F). Because the average temperature on Mars is below the freezing point, there is no liquid water today on its surface. But this was not always the case. Photographs of dry riverbeds on the Martian surface taken from orbital spacecraft show that in its distant past Mars was much warmer and wetter than it is today. For this reason, Mars is the most important target for the search for extraterrestrial life, past or present, in our solar system. The Martian day is very similar to that of Earth—24 hours and 37 minutes—and the planet rotates on an axis with a 24° tilt virtually equal to that of Earth, and thus has four seasons of similar relative severity to our own. Because the Martian year is 669 Martian days (or 686 Earth days), however, each of these seasons is nearly twice as long as those on Earth. Mars is a big place; although its diameter is only half that of Earth, the fact that it is not covered with oceans gives the Red Planet a solid surface area equal to that of all of Earth’s continents combined. At its closest, Mars comes within 60 million kilometers of our world; at its farthest, about 400 million kilometers. Using present day space propulsion systems, a one-way voyage to Mars would take about six months—much longer than the three-day trip required by the Apollo missions to reach the Moon, but hardly beyond human experience. In the nineteenth century immigrants from Europe frequently took an equal time to sail to Australia. And, as we’ll see, the technology required for such a journey is well within our reach.

  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 adva
nced 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.