Mars: The Outpost Of Imagination

Mars: The Outpost of Imagination By Sally Morem Note to Readers: I wrote this essay for the Minnesota Space Frontier Society’s newsletter, L-5 Points. It was originally published in a huge Mars Special Edition in the spring of 1986. Other than fixing a few typos and grammatical errors, I haven’t updated this essay. This was where we were with reference to Mars in 1986. There is something about the planet Mars that grips the human imagination. For hundreds of years, it seemed to fulfill our deepest yearnings for another world—a world in which resided all manner of strange beings—a world as filled with life as our own. Planetary space probes have shown us that Mars is not the planet we had hoped for. But, with hard work and scientific ingenuity, our descendants could transform it into a place that would rival our most beautiful fantasies.

Mar in Imagination Before astronomers understood what planets really were, Mars was attributed with human characteristics. The distinctive red color reminded them of blood and violence. Each ancient civilization had its own name for the War God. The Babylonians called it Nergel, the Greeks worshipped Ares, and the Romans gave it the name which we use today—Mars. Much later, Copernicus showed that Earth was an ordinary planet orbiting the Sun. Then, telescopes revealed that the other planets were solid bodies of matter, like Earth, or balls of gas moving through space. People then realized that Mars was open to interplanetary travel, if only the means could be found.

Since observers had seen clouds, canals and seasonal changes on the surface of Mars, they were led to believe that it was Earth’s twin. However, Mars is somewhat smaller and colder than Earth, so scientists speculated that its inhabitants were adapted to these conditions. Astronomers also determined that Mars had a thin atmosphere which led storytellers to describe Martians with huge, lung-filled chests. Europeans were so sure that Mars was the home of intelligent life that when a group of Parisians offered a reward to the first person to make contact with extraterrestrial life, meetings with Martians were disallowed. The French thought that these would be too easy to achieve. Writers began populating Mars with a wide variety of intelligent aliens. When Schiaparelli described what he called “canali” on the surface of the planet, imaginations soared. Percival Lowell assumed that the lines were artificially constructed canals, built to save a dying civilization from draught. A thousand tales followed, including H.G. Wells’ “War of the Worlds,” which described Martians desperately reaching out for a more habitable planet. Even after the 200-inch Palomar telescope showed no canals, the speculation did not stop. Science fiction writers got around this discrepancy by using underground Martian cities as settings for adventures. Asaph Hall’s discovery of the two moons of Mars added to the fervid speculation. To the imagination, this meant that Mars was even more Earthlike than was thought before. Since Earth had a moon, it was only right that Mars should have two moons. But, Phobos and Deimos (Fear and Panic), named after the horses that pulled Mars’ chariot, proved to be far less substantial in size than our Moon. They were more like asteroids caught in Mars’ gravitational field with their small, irregular shapes, than full-fledged moons.

Mars in Reality By 1926, astronomers had determined that Mars was too cold for water to exist on its surface in any form but ice. Instrument readings also showed that Mars had a very thin atmosphere—perhaps as little as 10 % of Earth’s.

Then in 1947, dreams of Martians took another beating when astronomers discovered that the atmosphere of the planet was made up almost entirely of carbon dioxide. Little water vapor and no oxygen—so essential for life— were found. Writers were disenchanted, but scientists held out hope for the existence of primitive life forms embedded in the soil. During the International Geophysical Year in 1957, such life forms were found in Antarctica. They seemed to have survived severe Martian-type weather. Scientists knew that the only way to find out more about life on Mars was to go and see for themselves. Wernher von Braun, one of the leading rocket scientists from Germany, speculated on how this might be done. No scientist in the late 1940s could have envisioned the ability of unmanned space probes to gather huge amounts of information on planets. So, von Braun planned a manned mission to accomplish this. In 1948, von Braun published his description of an elaborate plan to visit Mars in “The Mars Project.” A crew of 70 would be transported by 10 4,000-ton ships to Mars. 46 shuttles would haul parts up into orbit 950 times where the ships would be assembled. Von Braun made the mistake of not including a space station in his plans. After the ships achieved Mars orbit, 50 astronauts would descend to the surface in three large landing boats. Von Braun had more confidence by 1956 in the ability of engineers to design durable spacecraft, so he scaled down the redundancies in his huge proposal. In his new plans, each ship would weigh 1,870 tons and would require only 400 shuttle trips to be assembled in orbit. But, again, he neglected to add a space station to his plans, which would have drastically reduced the need for so many shuttles. Needless to say, the American space program did not follow von Braun’s recommendations. As sensitive instruments were designed for and used in Earth-orbiting satellites, space scientists realized that these could be adapted for unmanned missions to the planets. On November 28, 1964, NASA launched Mariner 4. It passed Mars in July, 1965 and took 20 pictures. These pictures revealed a crater-pocked, moonlike planet. The atmosphere was not 10 % of Earth’s as was originally

believed, but closer to 1 %. The dream of discovering an ancient Martian civilization finally died for good. The idea of colonizing Mars replaced fantasies of Martians, as illusions of canals were relinquished in favor of visions of irrigation projects supplying future human settlements with needed water. Science didn’t destroy the idea of traveling to Mars. It gave that ancient dream a firm technological basis in reality.

Mars as a World NASA followed up the success of Mariner 4 with Mariners 6 and 7 in 1969. They took more and better pictures as they passed by Mars, confirming the earlier findings. Then in November of 1969, Mariner 9 went into orbit around Mars. It arrived during a dust storm, making it nearly impossible to take pictures of the Martian surface. The storm did explain Lowell’s observations of changing light and dark areas on the surface of Mars. Martian dust causes the seasonal patterns, not changing vegetation. When the dust storm finally died down, Mars was revealed as a truly alien world. No canals were found, but the reality was just as startling as that old illusion. Mariner photographs revealed the existence of a huge bulge of volcanic material covering one-quarter of the planet. It’s the size of North America. The Tharsis Bulge, as it is called, is made up of dozens of huge volcanoes, which have remained dormant for billions of years. Towering over everything else is Olympus Mons (named for Mount Olympus), the largest known volcano in the Solar System. To give you an idea of the scale of this monster, the State of Rhode Island could fit neatly into the crater of Olympus Mons while Mount Everest would reach only to the 29,000-foot level of the volcano’s 88,000 feet. When these volcanoes formed, they ripped apart the surface of Mars, leaving gigantic canyons alongside the Tharsis Bulge. Valles Marineris (Mariner Valley, named for the space probes), is enormous by Earthly standards. The Grand Canyon’s 280 miles would make it seem like a small tributary alongside the 3,000-mile, two-mile-deep Valles Marineris.

Everything on Mars seems scaled to gigantic proportions. Mariner 9 photographs revealed what appear to be vast flood plains and riverbeds, indicating that Mars was once a watery world. The winding valleys travel downhill and are joined by tributaries, which show erosion deposits. They then open onto broad plains with delta deposits similar to that found at the mouth of the Mississippi River in New Orleans. An immense amount of water must have run freely in a comparatively short time. Perhaps the volcanoes brought it to the surface. Or, perhaps asteroids, filled with ice, crashed onto Mars billions of years ago. Scientists would not only like to know where it came from; they would also like to know where it went. Mars with its weak gravity may have lost most of it to space over the eons. Or, it may be locked up underground in permafrost or frozen into the polar icecaps. Landslides in Valles Marineris have been shown to be linked to the slow removal of underground ice. The resulting weakening of surface rock causes the ground to give way. If Mars had been watery in the past, does this mean that life could have developed ages ago, life that now lies dormant in Martian soil? Scientists planned the voyages of Vikings 1 and 2 in part to attempt to find answers to this question. The Vikings were launched in 1975 and began orbiting Mars in July and September of 1976. Each spacecraft consisted of an orbiter and a lander, all four of which performed successfully for years. The last of the four—the Viking 1 lander—finally ceased operations in November of 1983. The Jet Propulsion Laboratory held a ceremony celebrating the successful touchdown of the Viking 1 lander on July 20. Ray Bradbury captured the feelings of those present and of everyone involved in the space program by saying, “Today, we have touched Mars. There is life on Mars, and it is us— extensions of our eyes in all directions, extensions of our sense of touch, extensions of our mind, extensions of our heart and soul have touched Mars today. That’s the message to look for there. We are on Mars. We are the Martians.” While the landers photographed landscapes and dug soil samples, the orbiters mapped the entire planet. Some details on the planet Mars may be

useful here: The diameter of Mars is a little over 4,000 miles as compared to almost 8,000 miles for Earth. Mars has a 24-hour, 37-minute day and a 687day year. The axial tilt of Mars is 24 degrees, almost the same as Earth’s. Mars, like Earth, has seasons. And since Mars is smaller and less dense than Earth, its surface gravity is about one-third that of Earth’s. A 150-pound man would weigh about 50 pounds on Mars. The Viking orbiters determined that Mars has a very thin atmosphere indeed. It is actually about 1/125 that of Earth’s. This, and the fact that Mars is much farther away from the Sun, makes Mars a cold planet compared to Earth. The normal temperature range recorded by the orbiters runs from 150 degrees below zero Fahrenheit to 10 degrees below zero F. But, it can rise to a balmy 70 degrees above zero F. on a hot summer day on the equator. However, the atmosphere is not thick enough to protect the surface from damaging ultraviolet rays. There is no protective ozone layer over Mars. The orbiters revealed that Martian dust storms can get very fierce. As dust in the atmosphere gradually soaks up solar heat, dust devils form, rise and expand all over the planet. This process can take as little as five to six weeks. A planet-wide storm can last from 10 to 25 weeks. 125 miles-perhour winds can blow around the planet, with gusts up to half the speed of sound. This turbulent atmosphere was found to be made up of 95 % carbon dioxide with small amounts of nitrogen, argon, oxygen, carbon monoxide, water, and trace elements of other gases. When scientists selected the landing targets, the Viking landers separated from the orbiters, deployed parachutes and descended gently to the Martian surface. They then took magnificent photographs of a surprisingly red terrain. Tests of soil samples helped to explain the presence of this distinctive hue. The soil consists largely of iron, magnesium and calcium. There is enough oxygen in the atmosphere to oxidize the iron, turning it red. During dust storms, the Martian sky is pink with billions of tiny oxidized dust particles suspended in it. The landers and orbiters kept taking pictures during many seasons, showing how ices accumulate on the ground during the long Martian winters and evaporate during the summers. The icecaps could also be seen growing and

shrinking during the year. Along with the other indications of water, the ice tantalized scientists with the possibilities of life on Mars. Certainly the prospects for life didn’t look that good with such a cold and unprotected planet. But as was mentioned before, life exists in Antarctica under similarly brutal conditions, so the possibilities couldn’t be ruled out. In any event, NASA scientists realized that if any Earth organism got into a Viking lander and contaminated Mars, all of the life experiments would be rendered useless. So, both landers were “cooked” for forty hours in an oven set well above the boiling point for water. They were then carefully loaded aboard the Viking spacecraft for their long voyage. NASA hoped that the steps taken would be enough. Each lander was equipped with a manipulator arm that could test the atmosphere at the landing site and take soil samples. Some of the soil was then tested for signs of microscopic life. Unfortunately, the tests were set up to detect the presence of complex organic compounds only. None were found. But, odd chemical reactions did take place, which have not been fully explained to this day. There is no way now to determine with certainty if the reactions were a result of strange soil chemistry or the existence of very alien life forms. After Viking, it does seem unlikely that even very different life forms could survive the hostile environment of Mars. The combination of thin atmosphere, fierce radiation, severe cold, scarcity of oxygen, carbon dioxide atmosphere, and lack of complex organic compounds seems to add up to the existence of a sterile world. But, we can’t be absolutely sure—yet. David E. Fisher, a Miami geochemist, expressed the frustrations of scientists around the world when he wrote, “The worst thing any…could envision was that they would go to Mars…and still wouldn’t be able to say for sure whether there was life up there or whether the planet was barren and dead. So, guess what happened? Right!”

Proposed Unmanned Missions to Mars Many unanswered questions stimulated talk of follow-up missions to Mars, while the successes of Viking showed scientists that unmanned space probes could gather detailed information on other planets. As a result, NASA and

private space groups have proposed several different unmanned missions to Mars for the late 1980s and ‘90s. The Mars Observer, formerly called the Mars Geochemistry/Climatology Orbiter, will be launched by the Space Shuttle in August of 1990 and will reach Mars orbit the following August. Current plans call for a modified RCA communications satellite, along with a booster rocket, scientific instruments, solar panels, and a high-gain antenna, to go into a 224-milehigh polar orbit around Mars. This low orbit will allow the Observer to map the entire planet with as much detail as the Landsats have achieved. The Observer will use gamma ray and infrared spectrometers to pinpoint locations of minerals and ices on the surface, to estimate amounts of water vapor and dust in the atmosphere, to measure temperature and barometric pressure at all altitudes, and to reveal the chemical composition of every area of Mars. Scientists hope to be able to determine the climatological history of Mars and to produce a detailed mineral map of the planet with the help of Observer. Many space scientists believe that NASA should launch a sample-return spacecraft to Mars or to its moons later in the 1990s. One proposal calls for a Mars Observer-type space probe to conduct film mapping of Mars at a very low altitude and to retrieve a sample of Phobos for study on Earth. Another proposal describes a vehicle that would land on Mars, collect soil and rocks, rendezvous with an orbiter, and return to Earth. A more sophisticated version of this would include a Mars Rover, a vehicle that could range 100 miles while stopping to take samples along the way. It is believed that one sample-return mission could be undertaken in the late 1990s for about $2 billion. We know that the Russians are interested in performing such missions. Right now, they are planning to fly two unmanned spacecraft to Mars in 1988. They will orbit Phobos and Deimos, and perhaps land on these and take samples. This could be the prospecting trip for a future manned mission to Mars.

The Case for Mars

In 1977, as a result of the scientific discoveries of Viking, several University of Colorado graduate students met and discussed the future of human space exploration. They agreed to consider the possibility of colonizing Mars. They contacted several space scientists and asked for information on Mars mission proposals. As a result, they discovered the Mars Underground, an extensive network of scientists and engineers who were privately working on various ideas for colonizing Mars. A surprising amount of interest developed throughout the space community in what the Colorado students were doing. As a result, the students agreed to hold a national conference on Mars at the Boulder campus of the University of Colorado. Invitations were sent out to scientists, engineers, and authors across the nation. Several were asked to prepare papers on every aspect of a Mars mission, including propulsion, design, life support, medicine, psychology, and costs. “The Case for Mars” conference turned out to be a huge success. Even though NASA didn’t support the conference, many of its employees traveled to Boulder at their own expense. Nearly 100 people participated. They met during a weekend in April of 1981 and succeeded in hammering out a mission strategy for a voyage to Mars. The general consensus was that a manned mission to Mars was not only possible, but probable, and that it would actually cost less than the Apollo program (after accounting for inflation), even though getting people to Mars is much more difficult than getting them to the Moon. Participants in the conference realized that Space Shuttle and space station technology would be required in order for a Mar mission to work and to be economical. Less research and development for new technologies would be needed if older technologies could be used in new ways. The Shuttles and the space station could help assemble a Mars ship in orbit and Shuttle External Tanks could be used in the actual design of the ship. After the crew arrived at Mars, the landing party would set up camp, the components of which would be designed in such a way that would allow it to become the core of a future Mars colony. Intensive exploration and experimentation on Mars would keep the crew busy until the return trip.

The reaction to the proposals from participants in The Case for Mars ranged from enthusiasm, to polite interest, to disdain for what was seen as yet another space boondoggle. But NASA, private enterprise aerospace companies, and even the Russians kept a discreet watch on the proceedings. Clearly, they thought something important was happening in Boulder. Perhaps the Russians were gathering ideas for their own preparations for an eventual manned mission to Mars. They have sent their cosmonauts into orbit for six months at a time, launched Salyut space stations into orbit, and experimented with long-term life-support systems. They have actually grown food while aboard Salyut. All of these activities indicate that they are trying to master the technology necessary to take the long journey to and from Mars. The Case for Mars succeeded, not just because scientists got together and exchanged ideas on Mars, but because in doing so, interest was raised and space advocates were mobilized in support of a proposed manned mission to Mars. As a result of the ideas generated at the conference, the Planetary Society established the Mars Institute, which sponsors university courses and seminars on Mars. It was hoped that this would allow ongoing studies to be established on Mars proposals. When the follow-up conference, “The Case for Mars II” was organized, interest was widespread in the space community. The expenses of NASA and other government employees were paid by the government. The Planetary Society, the National Space Institute, and the American Astronautical Society joined the University of Colorado Space Interest Group in co-sponsoring this second conference. The Case for Mars II was held July 10-14, 1984 in Boulder to refine ideas discussed in 1981 and to consider new information and new ideas, which had come up since then. Participants described very detailed scenarios for the exploration and colonization of Mars.

Preparations Mission planners may choose to send unmanned cargo ships to Mars ahead of the manned spacecraft, not only to save space, but to save fuel. The cargo

could be hauled by solar sails—huge sheets of super-thin plastic film pushed by the solar wind. One cargo ship could bring a robotic refinery to the selected site on Mars where it would begin to process the carbon dioxide in the atmosphere into oxygen. An electrolytic pump would take in air, remove dust, and separate oxygen from carbon monoxide. The oxygen would be stored for later use. When the astronauts arrive, the oxygen would be there, ready for use as life support and rocket fuel. Such “gas stations” could also be designed to make use of any permafrost found on Mars. According to a 1985 study by NASA, there should be plenty of water ice on Mars for future use. Scientists studied data from Mariner and Viking photographs and determined that Mars might have 10 to 100 times more water than they had previously believed existed. Certainly no properly prepared mission will lack for air or water on Mars. Choosing a crew for this mission will be no easy task. The voyage will take several years and this will put the crew under severe psychological strain. Experience in Antarctica may help overcome these problems. First, each potential crew member must be screened for psychological weaknesses. Then, mission planners should select a larger crew than might otherwise be considered necessary since it is very difficult for anyone to face the same few people every day for years. To help avoid monotony, the duties of each crew member should be varied. Skylab and Shuttle crews have indicated the need for time away from work for rest and recreation. It would be helpful if they used a large share of that time for vigorous exercise—not only for physical therapy, but also to help their mental state. And finally, the spaceship should be designed with people in mind. Each member of the crew should be given a private area for his or her own use and the living areas should be attractive. People should not have to travel for months in space-age Spartan white. There are physical dangers that will have to be dealt with on a Mars voyage. Human beings will be very vulnerable to radiation and will have to be shielded. And, prolonged periods of weightlessness could also pose a threat to health. Soviet cosmonauts have discovered during long stays in space that muscles and bones deteriorate, organs in the abdomen drift upwards, the heart enlarges, and the bones renewal system shuts down completely. No

one knows if after a year-long voyage to Mars, a person could tolerate gravity again. The spacecraft that will bring astronauts to Mars will have to be carefully designed to help avoid these problems. The Case for Mars conferences proposed building the Mars ship out of three self-sufficient 60-meter-long modules, based on space station technologies. After auxiliary boosters accelerate them out of Earth’s orbit, they would link together in a Y shape and start spinning at a rate producing 1/3 Earth gravity, mimicking Mars’ surface gravity. This would allow astronauts to avoid the problems associated with prolonged weightlessness and prep them for life on Mars. One side of all three modules would always face the Sun. This side would contain the bulk of the mass, including communications, solar furnaces, propellant tanks, and engines. These would act as a shield for the side facing away from the Sun, which would contain Mars shuttles, living areas and astronauts. In this way, the crew would be protected from most radiation. We have Space Shuttle technology and we will soon have space station technology in hand. These are absolutely necessary for a Mars mission to be successful. The space station will not only be used as a prototype for the spaceship, but also as a base for the construction of the ship in Earth orbit. A Mars ship would be far too large to launch from the Earth’s surface. The development of a closed-loop life support system is also necessary. The crew can’t afford to throw away its wastes when no consumable can be delivered to the ship. Air and water must be completely recyclable. Here again, the space station could serve as prototype. As engineers learn to recycle wastes and humidity, the necessity for hauling air and water up from Earth will disappear.

The Journey Outward When Mars is 44 degrees ahead of Earth in their respective Solar orbits, a conventional rocket can be launched from Earth orbit and coast to Mars in about ten months. However, these launch windows only occur about every two years. This means that such a mission could not consist of an Apollo-

style visit. Mission planners must prepare for the long-term exploration of Mars as an integral part of a mission to Mars. Phobos and Deimos may be the first destinations of a manned mission to Mars. The astronauts would set up permanent bases there, using the frozen water in the life support system and as return fuel. The absence of life on Mars has not been proved yet, so it might become necessary for astronauts to stay off the surface of Mars until the scientists are reasonably certain that alien life forms would not be contaminated by Earth life. Phobos and Deimos could serve as weather observation stations, astronomical observatories, communications centers and tele-operator bases. Tele-operators would operate remote-controlled vehicles on Mars. These could include airplanes with huge wings to give loft in thin Martian air and dirigibles loaded with cameras and other gear. After scientists determine it’s safe, astronauts would get the go-ahead to land on the planet. But, what happens if the low-gravity environment of Mars’ moons proves to be too debilitating to astronauts? Would planners have to abandon the idea of using them as bases? In that case, the crew would go directly to the surface of Mars after the long trip. The possibilities of life on Mars will have to be eliminated before the manned mission could begin. If this is the case, the Mars mission will go something like this: When the spacecraft has achieved Mars orbit, the three Mars shuttles will bring astronauts to a pre-selected site near where the Mars “gas station” is operating, busy extracting oxygen from the atmosphere, perhaps for years. The long lag-time between Mars to Earth mission windows precludes the possibility of a quick return to Earth. Instead, the crew would establish the beginnings of a permanent Mars base.

Mars Base I Before we can fully plan a Mars base, a Lunar base will have to be established. That’s the only way to get the necessary experience in constructing underground habitats, setting up a workable life-support system, and establishing food growing areas on an alien planet. A Lunar base will take much of the guesswork out of the work that will have to go into building a Mars base.

Most heavy equipment will have to be sent on ahead in the unmanned cargo ship so that it will be ready at the site when the astronauts get there. Several Space Station-based habitat modules, a nuclear power module, a Mars rover, construction cranes and forklifts, soil moving equipment, communications equipment, as well as the Mars gas station will make up the bulk of the Mars base. The crew will busy themselves by excavating the sites for the habitats. These will be put in place and then will be covered by several feet of Martian soil to protect crew members from solar radiation. Along with the habitats, large recreation and farming structures will be set up. Growing plants may require reflecting mirrors to focus solar rays since the Sun is too far away from Mars to give Earth plants the required amount of energy to grow. Horticulturalists will find out how plants react to the low Martian gravity fairly quickly. The crew will melt permafrost for water, and electrolyze it for air and additional fuel. They will also set up a laboratory to study how various processes work in Martian gravity. The entire base will be powered by a nuclear generator capable of producing one to ten megawatts of electricity. The Mars base will be kept in continuous communications with Earth by placing satellites in orbit around Mars.

Explorations In order to explore Mars, the astronauts will have to be supplied with efficient spacesuits designed specifically for the Martian environment. Apollo and Space Shuttle suits are too bulky for a planet with 1/3 Earth gravity and an atmosphere (even though thin), so the suits will have to be skin-tight and flexible with the ability to recycle body wastes. The astronauts will thoroughly explore the area around the base by taking tens of thousands of photographs, choosing samples in interesting geological areas, leaving ground instruments for future monitoring, taking core samples and analyzing both air and rock samples for very detailed chemical compositions.

There will be much to explore. It will take many missions to explore the vast, extinct volcanoes, mountains that look like vast pyramids, the deep canyons, the great alluvial river valleys, the broad plains, and the polar ice caps. These will give people fascinating things to study for centuries to come. A thorough exploration of Mars may give us answers to questions on the history of climate and geology of Mars. One of the most curious things about Mars is the Tharsis Bulge. How did such a huge structure form? Scientists believe that volcanic activity began three billion years ago at what was then the North Pole. Since Mars has no plate tectonic activity, the crust of Mars is in one piece. And so, the volcanic material had nowhere to go. It piled up in one place. However, the most stable alignment that a spinning object can achieve is having the most massive objects farthest from the axis of rotation. On a planet, that’s the equator. When the Tharsis Bulge developed at the North Pole, the weight created an instability. To compensate, the crust as a whole moved until the volcanoes were near the equator. Everything shifted, including the old poles. The resulting pressure ripped apart the surrounding area, creating Valles Marineris. Astronauts will be able to study such things as deposits made by ancient ice caps now near the equator and the direction of impact of old craters to check out this theory. Confirmation will add immeasurably to planetary science. Scientists also believe that the atmosphere of Mars forms a natural laser. Carbon dioxide causes Mars to emit radiation at the same wavelengths as commercial lasers. It’s believed that Mars produces over one billion kilowatts of power each year in this manner. A careful study of this phenomenon by astronauts could be used to construct satellites made up of carbon dioxide, which could generate power in the same way. The crew would certainly want to visit the old Viking landers. Viking I has been made an official part of the National Air and Space Museum. When people finally visit it, it will be named a Smithsonian museum in its own right. Astronauts on the first manned mission may indeed conduct the official ceremony.

Going Home As the time approaches for the return to Earth, the crew will be busy packing samples of rocks, soil, and Mars-grown plants. They will also carefully arrange fuel, equipment and supplies needed for the long trip home. They will close down the base so that everything will be ready for the next crew. A regularly scheduled Mars Transportation System would allow the base to be permanently manned. As the first crew prepared to leave, another one would arrive. The first crew would return to Earth on the ship that brought the new crew. New crews would expand and improve the base until it could truly be called a Mars colony. At that point, some people may choose to live on Mars permanently. They would earn their living by mining Mars, growing food and providing services for visitors. Eventually, the Mars Colony would become selfsufficient. New colonies could be established. The settlers could set up fuel refineries for travelers to the Outer Solar System and ship nitrogen and other needed raw materials to back to the Earth-Moon system for use by space stations and L-5 colonies. The new Martians would live at the edge of a rapidly growing Solar System Civilization.

Advanced Propulsion Systems At that point in time, spacecraft that coast most of the way to Mars with chemical rockets will no longer be good enough. Faster delivery of passengers and goods will be greatly appreciated. An engine capable of continuous thrust at one gravity would take a spaceship from Earth to Mars in two weeks, a huge improvement over the present ten months. But, how could the required energies be tapped? A wide variety of technologies are possible. A laser propulsion system would create high temperature plasma, which would transfer energy to a hydrogen-propellant, creating the required continuous thrust. If Solar Power Satellites are developed, microwave energy could be beamed to an array of solar cells on the spacecraft, which would allow it to move with no fuel on board.

A mass driver could use Lunar base-derived technology to launch cargo to Mars. Metal fuel accelerated by magnetic fields would provide the thrust for an ion-drive ship. Pulsed fission would use, in effect, small atomic bombs to drive the spacecraft. This idea had been developed in the 1960s under the code name NERVA. A fusion reactor would also create the required energy. In a century, we could be moving about the Solar System in a matter of weeks, instead of years.

Why Mars? With all the possible things we could do in space, the question arises, “Why should we go to Mars?” Unmanned spacecraft have certainly been successful in gathering scientific knowledge on Mars. We could get plenty of raw materials for space industrialization and settlements from the Moon and the asteroids. Eric Drexler has seriously questioned the points raised by The Case for Mars conferences. He believes that a mission to Mars is a symptom of the old “planetary chauvinism,” which afflicts some space scientists: “Space is something to travel through on your way to another planet.” He counters by saying that space is in fact a useful place. It is easy to build large structures there. In contrast, Mars is not a healthy place to live. The thin atmosphere, constant radiation, and low gravity make it hard to establish a viable settlement. He acknowledges that Mars has nitrogen, a rare element on the Moon and in the asteroids. It may prove profitable for future space entrepreneurs to mine it one day. But, after all the facts are considered, it will prove much easier to build and furnish L-5 space colonies rather than a Mars colony. Also, more people could participate in space development in the Earth-Moon system than in far-off Mars. Drexler’s objections would be valid if all that was being proposed was a Mars mission. However, I believe that it has been made quite clear that no Mars mission could be undertaken at reasonable cost if no other space development projects were going on.

There will be no Mars mission without a space station and a Lunar base. Too much technology and experience is riding on these projects. The spaceship and the Mars base living quarters will use space station module designs and the space station will serve as a construction shack for the assembling of the Mars ship. The Lunar base will serve as prototype for the Mars base. The construction of underground facilities, establishment of agriculture and development of mining procedures will all begin on the Moon. No Mars base could possibly develop all of these technologies from scratch and stay within budget. Consider all the other technologies that will become greatly advanced before we even start to put together the components of a Mars mission: Solar Power Satellites, improved rocket propulsion systems, space manufacturing and materials processing, space mining, closed-loop life-support systems, space agriculture and space medicine, not to mention the actual long-term experience of living in space. Exploring Mars will be far easier then. Even so, what The Case for Mars participants are doing now makes sense. They are asking questions about what will actually be needed to visit Mars and to eventually settle there. Even more importantly, they are asking what we can do on Mars. And they’re coming up with some interesting answers. Daniel Webster described the vast lands west of the Mississippi River and asked, “What do we want with this vast, worthless area, this region of savages and wild beasts, of shifting sands and whirlpools, of red dust?” In one century, that land helped the United States to become very rich and powerful. We don’t know how much wealth is in Mars, but then again we don’t know how much wealth is in the Moon and the asteroids. One of the jobs for astronauts on Mars will be to find out. We may discover that mining the moons of Mars will be economical. It will actually take less energy to launch materials from Phobos and Deimos to low-Earth orbit than from our Moon. Again, we don’t know. We should find out. We could use a Mars mission as a technology development program. In order to get to Mars and to stay there, we will have to learn to do things that

will normally take decades to learn. For instance, a Mars base may be just the stimulus needed to develop constant-acceleration propulsion systems. Mars will have then indeed opened up the rest of the Solar System to us. Certainly, we will go to Mars for science. We can’t learn some things only by using “the next best thing to being there.” We have to be there. How will mission planners set up a mission to Mars in the 21st century? We don’t know. Our task is to leave them with the widest range of possibilities from which to choose. We can do that best by covering all the bases now. We may wish to have another Case for Mars conference in 1987 or 1988. This will give space scientists a chance to discuss proposals and technologies which have come about since 1984. We don’t know what use our descendants will make of the other planets of the Solar System. Perhaps the proponents of space colonies are right— planets are useless. Maybe in a few centuries the planets will be blasted into useful asteroids. Or maybe they will be used as rugged testing grounds for future technologies, as International Falls, Minnesota is used today for cold weather testing. Maybe they will find that planets can be very useful if they are terraformed. They may use some of James Oberg’s suggestions to turn Mars into a twin of Earth. Dark soot could be taken from Phobos and Deimos and sprinkled all over the surface of Mars to decrease the amount of solar heat re-radiated into space. This would start a Martian greenhouse effect, melting the polar ice caps and thickening the atmosphere. Biological materials could be introduced to increase the greenhouse effect and to induce changes in the composition of the atmosphere, including the addition of more oxygen. Giant space mirrors could reflect more solar rays onto the surface of Mars. And finally, plants and animals could be introduced from Earth into the newly formed ecology to keep it stable. Whatever is finally decided, we should not argue now from a zero-sum perspective. That’s not what space development is all about. Of all the science writers, G. Harry Stine says it best: “If we play the cards correctly in the next quarter of a century and turn the Solar System into a useful and valuable place to work and live, we will have created a situation in which

everybody wins—scientists, industrialists, financiers, entrepreneurs, and everybody on Earth and in space.” At that point, the dreams of the scientists, the engineers, the poets and the science fiction writers will have come true. The outpost of imagination will be Mars…because the outpost is also always ourselves.