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from “To Mars or Not?” by Ray Jayawardhana
1 In the mid-1990s, NASA dedicated nearly half of its budget for planetary exploration to Mars alone. That is largely because Mars is a potential habitat for past—or future—life. Mars is also, in many ways, the next logical destination for human space travelers beyond our moon, which the Apollo astronauts visited between 1969 and 1972. Mars is only about half the size of Earth, with a very thin atmosphere dominated by toxic carbon dioxide gas, a frigid climate, and massive dust storms. Yet those conditions are preferable to the hellish temperatures, bone-crushing pressures, and acid rain on our other neighbor, Venus. This is why American and European space programs have turned their focus to Mars.
2 In 2010, President Barack Obama announced a new direction for NASA, including a call to develop new rocket technologies to send humans beyond the moon. “By the mid-2030s, I believe we can send humans to orbit Mars and return them safely to Earth. And a landing on Mars will follow, and I expect to be around to see it,” he declared in a speech at the Kennedy Space Center in Florida.
3 This new national space policy replaced President George W. Bush’s 2004 plan, which would have included a return to the moon by the year 2020. Some critics, including Neil Armstrong, the first person to step on the moon, disagreed with the change in direction. President Obama responded, “I just have to say pretty bluntly—we’ve been there [to the moon] before…. There’s a lot more space to explore and a lot more to learn when we do.”
4 A human mission to Mars is challenging, expensive, and risky. So, is it worth it? You decide.
The Case for Mars
5 Studies of Mars can shed light on several important scientific questions, from the origin and survival of life to the process of global climate change. Among the bodies in our solar system where life might have developed, Mars probably ranks next after Earth. Based on what we know, the ingredients needed for life are few: energy, organic molecules (the carbon-containing building blocks that make up living things), and a liquid, probably water. Ancient river basins on Mars and soil just below the surface (especially near the polar caps) seem to satisfy these criteria. Does that mean life began on Mars but didn’t survive? Why or why not? We just don’t know. Human exploration, with scientists among the crew, could provide answers.
6 Mars also displays a rich variety of geological features. It appears to have been wet once, perhaps with flowing water and large lakes. That suggests the red planet was warmer in the past. It may have gone through periods of substantial greenhouse warming, when gases such as carbon dioxide and methane in its atmosphere trapped more heat. We might be able to find evidence of such times in the planet’s geological record. And understanding climate change on Mars could give us clues about the future of our own world.
7 Some scientists think it will take human geologists, not just robotic missions, to unravel the mysteries of Mars. As Cornell University’s Steve Squyres, lead scientist for the two robotic Mars rovers, told Space.com, “What Spirit and Opportunity have done in 5½ years on Mars, you and I could have done in a good week. Humans have a way to deal with surprises, to improvise, to change their plans on the spot.”
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8 Astronauts on Mars offer something more: they have the ability to inspire people back here on Earth—and to change our perspective—in a way that robots do not. One of my cherished memories from childhood is the moment my father pointed to the moon during a walk in our garden in Sri Lanka where I grew up and told me that people had walked on it. I was astonished: the idea that one could walk on something in the sky boggled my mind. Suddenly that bright light in the sky became a place that one could visit; the world felt a lot more exciting and the possibilities seemed endless.
9 Looking back, that moment has had a defining impact on the path I have taken in life. Like many kids, I dreamed of becoming an astronaut. That desire fostered my interest in science and eventually led me to a career in astronomy. And I’m not alone. A lot of scientists and engineers who grew up in the 1960s and the early 1970s say that the Apollo missions inspired them to enter technical fields. What’s more, some historians think that the stunning image of Earthrise over our moon, taken by Apollo astronauts, changed humankind’s view of our home planet and sparked the global environmentalism movement in the 1970s.
10 Robert Zubrin, a well-known advocate of sending people to Mars, argues that such a mission would “reaffirm the pioneering character of our society.” He and others suggest that Mars is the obvious next step in human exploration. Some think a Mars mission could also serve as a “grand challenge”—an unsolved problem that drives technological progress and unites a nation (or multiple nations) behind a common goal.
11 As Chris McKay, a scientist at NASA’s Ames Research Center in California, told me: “If our only interest in Mars was planetary science and the search for past life, then perhaps humans would not need to go. But our real question is how Mars will fold into the scope and extent of future human activities. Will we go there? Will we stay there? Will we bring that planet back to full life? These sorts of questions require human involvement.”
12 In other words, he added, “I think the main reason to send people is not so much to answer the question ‘was there life on Mars?’ but to address whether there could be life on Mars in the future.”…
The Case Against Mars
13 Many of the scientific questions about Mars can be addressed without human visitors. Spacecrafts have already mapped the red planet extensively from orbit, determined where various minerals are distributed, and identified regions with buried water ice.…
14 As Rebecca Ghent, a University of Toronto geologist who studies Mars, explains, “The biggest argument for human scientific exploration of Mars is that a human geologist can do much more efficient and effective work on the ground than robots can.” But, she adds, “If I had to choose between a human geologist visiting one or two spots and loads of global remote data, I would choose the latter.” That is, while orbiting spacecraft and long-lasting rovers can gather data from all over Mars, astronauts would only be able to explore a tiny bit of the planet at a time. She admits that a combination of the two approaches “would be the ideal way to go about exploring the planet.”
15 A trip to Mars would create many new challenges for astronauts. The moon was only three and a half days away by rocket. Mars, on the other hand, requires a journey of at least eight months using today’s rockets—so a round trip, including time at Mars, could add up to over two years. Page 2 Go to the next page
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What’s more, the food and supplies needed for a two-year round trip might require an especially large and unwieldy spaceship.
16 The time delay for Apollo astronauts communicating with mission control in Houston was barely noticeable. That won’t be the case with a trip to Mars: it takes between 3 and 22 minutes for radio signals to travel between Earth and Mars, depending on their relative locations. That means astronauts visiting Mars will need to be more self-reliant. While astronauts have spent over a year at a time in space stations orbiting Earth, they know that it is possible to be rescued and brought back home fairly quickly in an emergency. A crew headed for Mars, however, will need to be prepared psychologically for the long separation from their home planet.
17 Another concern for astronauts heading to Mars would be their exposure to space radiation, which can damage DNA just like overexposure to X-rays or to ultraviolet rays from tanning beds here on Earth. Astronauts in the International Space Station are mostly protected from harmful space radiation because it sits within Earth’s magnetic field, which acts as a protective shield. But those who venture beyond Earth orbit face serious threats from solar flares and fast-moving particles that come from beyond the solar system. It is not easy to estimate how risky the radiation during a Mars trip would be.…
18 Once astronauts reach Mars, a smooth landing won’t be easy to arrange: the Martian atmosphere isn’t dense enough to help much with the braking. (And the weight of all that extra food won’t help, either.) Some combination of parachutes and rockets will be required to do the job. Once on the ground, astronauts will have to wear pressurized spacesuits, just like they did on the moon. That limits their efficiency and dexterity while exploring their new surroundings.
19 The Apollo program is estimated to have cost around 150 billion in today’s dollars. Estimates of the cost of sending people to Mars vary a lot, ranging from about $50 billion to $500 billion. While that sounds like a huge amount of money, in some ways it isn’t—especially if the cost is spread over one or two decades and is shared among several nations.… Still, there is little appetite among politicians or the public for an expensive new space program these days, given that the U.S. government is more than 13 trillion dollars in debt.
20 The Apollo missions took place during the Cold War, when the country was motivated to “beat the Russians” to the moon, but we have no such national motivation now. And other countries may not be interested in sharing the cost during a time of worldwide economic difficulties. Besides, many people think a human mission to Mars would distract from other pressing issues, such as poverty and global warming.
Excerpt from “To Mars or Not?” by Ray Jayawardhana from Cricket Magazine. © Carus Publishing Company. Reproduced with permission. All Cricket Media material is copyrighted by Carus Publishing Company, d/b/a Cricket Media, and/or various authors and illustrators. Any commercial use or distribution of material without permission is strictly prohibited. Please visit http://www.cricketmedia.com/info/licensing2 for licensing and http://www.cricketmedia.com for subscriptions.
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