Receive emails about upcoming NOVA programs and related content, as well as featured reporting about current events through a science lens. Email Address Zip Code Subscribe Some experts feel the only way we'll get people on Mars in the near future, rather than just robots as with the Viking landers (seen here on a 1970s postage stamp), is to contemplate a human mission that is not round-trip. Support Provided By Learn More © R. Blake Johnson/iStockphoto

"People who have never heard about this say, 'That is absolutely crazy,'" former NASA engineer Jim McLane, a leading advocate of the idea, told me. "And then after they think about it a little bit, they say, 'Well, maybe that would work.'" In fact, a number of space scientists, aerospace engineers, and astronauts have supported the notion. Their reasoning might convince you. Or not.

Not a suicide mission

Proponents wish to get one thing straight. "Most people misunderstand and think that we're talking about a suicide mission," says Paul Davies, a physicist at Arizona State University and one of the strongest voices stumping for one-way. "You know, we'll transport you there, you've got supplies for a week or something, and then you just slowly die. And that all seems grotesque. But, of course, that's not what we're talking about. We're talking about: You'll live out the rest of your days on Mars in discomfort but excitement."

"I just think we're not going to do it—simply for reasons of cost—without making it a one-way mission."

Even calling it a one-way mission rubs some advocates the wrong way. "I wish you wouldn't call it that," Buzz Aldrin told me as soon as we got on the phone recently. "At first glance, it's a turnoff. I think we should call it 'establishing human permanent presence at Mars.'"

"In other words, a one-way mission means a colonization mission," says Robert Zubrin, an aerospace engineer and codesigner of a well-regarded plan for a human mission called Mars Direct. "It's Plymouth Rock. You keep on reinforcing them with more people, more equipment, more of everything until you have a substantial settlement."

Plenty of historical precedent exists for one-way, colonizing missions, advocates say—from the ancient, seafaring Polynesians who discovered Hawaii, to the Pilgrims who arrived in the New World in 1620 set to stay. © Sylvana Rega/iStockphoto

In Zubrin's vision, following several robotic missions to deliver equipment and supplies, the initial astronauts would set up an embryonic colony—a basic habitat with greenhouses, water supplies, power systems. Every two years—the launch window for trips to Mars—more astronauts would arrive to join and resupply them.

"By mission number five, you're sending teachers and pediatricians, because this thing is turning from a field outpost into a human settlement," Zubrin says. Eventually, in the best of all possible new worlds, the colony would become self-sufficient, no longer needing any help from Mother Earth.

Cheaper

Permanent colony or not, what advantages does one-way have over round-trip, according to supporters? Above all, it's not nearly as pricey as two-way. "I would say three or four times as expensive to provide return capability," Aldrin says. Chris Kraft, the legendary NASA flight director, has estimated 10 times more costly, Aldrin told me. Much of that expense would lie in launching to Mars a return spacecraft and all the propellant needed for the months-long flight back to Earth. Even if the fuel could be manufactured on Mars—a key component of Zubrin's Mars Direct scheme—the cost would be much greater than if the crew just stayed put, backers contend.

"You could say the cost-benefit of a Mars exploration program would be measured by, say, person-days on Mars divided by ton launched into Earth orbit," Zubrin says. "Well, if they stay on Mars, it's going to get a lot more person-days. Instead of staying for a year and a half, they stay for the rest of their lives."

Faster

More affordably means sooner, endorsers say. McLane insists that one-way is the only approach that offers the chance that we in the current generation could see it happen. Davies agrees: "I just think we're not going to do it—simply for reasons of cost—without making it a one-way mission." Even in 50 years, Davies suspects, neither the financial nor the political wherewithal will exist to send astronauts to Mars to poke around for a short time and then whisk them home again, as we did with the Apollo astronauts.

By 2012, Russia expects to launch a robotic mission to the Mars moon Phobos (seen here in an artist's depiction on a Hungarian stamp). Such missions worry Aldrin, for one, who fears the United States might start falling behind in space exploration. © Jim Pruitt/iStockphoto

Aldrin worries that if the U.S. doesn't act soon, other countries may end up putting people on the Red Planet sooner than we do. In 2011, Russia plans to send a sample-collecting mission to Phobos, one of the moons of Mars (and, in Aldrin's opinion, the ideal staging point for a colonization of the planet). The so-called Phobos-Grunt mission includes a Chinese satellite. "If we don't shape up what we're doing," Aldrin told me, "we're going to find the Russians clearly leading missions to Mars."

Safer

One-way would actually be safer for the astronauts than round-trip, Zubrin maintains. "All of the risk associated with the return flight—taking off from Mars, interplanetary flight, then entering [our atmosphere] and landing on Earth—are no longer in the mission," he says.

"I think people would be standing in line to do this."

The interplanetary-flight part includes prolonged exposure to zero gravity, cosmic radiation, and perhaps solar flares. Doubling these impacts, proponents stress, could leave returning astronauts more susceptible to contracting cancer or other illnesses down the road than if they'd remained in secure habitats on Mars.

Doable now

Another advantage is we could achieve a one-way mission with current know-how, enthusiasts assert. We'd have to develop a sufficiently large launcher, but we wouldn't have to clear any great technological hurdles, Davies says. The same can't be said about round-trip, some argue, including launching off Mars. As McLane wrote in a 2006 paper, "Return to Earth from the Martian surface is a daunting technical problem for which current technology offers no obvious solution."

Zubrin thinks that, from a technical standpoint, we are actually much closer today to being able to send humans to Mars than we were to sending men to the moon in 1961, and we were there only eight years later. When I asked him if we should, to paraphrase Kennedy, go to Mars in this decade, he said, "I think that's exactly what we should do."

Just six and a half decades separated the first powered flight at Kitty Hawk in 1903 from the first moon landing in 1969. Could a similar stretch of time separate the first moon walk from the first permanent base on Mars? © Ray Roper/iStockphoto

Aldrin, while agreeing that we have "quite a good idea of how to do it," envisions a longer timeframe, more on the order of three decades. "It was 66 years from the Wright Brothers at Kitty Hawk to landing at Tranquility Base," he says, referring to the Apollo 11 landing site. Seventy years from that landing to establishing the beginnings of a permanent settlement on Mars sounds about right, he told me. But we should start now, he says, by proclaiming a "global space doctrine" on the 50th anniversary of Kennedy's speech in 2011, with a Mars colonization mission as its chief element.

Volunteers aplenty

Even if we committed ourselves to achieving the goal, to borrow Kennedy's words, who would go on such a lopsided mission? Would there be any takers? Aldrin believes that, for the chance to settle on Mars, there would be no shortage of volunteers among the astronaut corps. Davies says he has found the same at lectures he's given on the subject, where he typically asks who would like to sign up. "You'd think nobody would put their hand up, but it's surprising how many people do," he told me. Scientists, too, are intrigued. Davies recalls discussing the concept a number of years ago with Martin Rees, President of the Royal Society and England's Astronomer Royal, and Rees said he himself would volunteer.

"I think people would be standing in line to do this," Jim McLane says. "They would be more than heroes—they'd be like Adam and Eve in the Bible. They would become legend."

"I think what people are not keeping in mind is what a truly horrible place Mars is."

Just think, supporters say: The first martians would be instantly renowned. The very fact that he, she, or they wouldn't return would keep people around the world riveted by their story—the ultimate reality show. The pioneers would be on the greatest journey of exploration ever undertaken, a trip that might make Columbus's voyages feel strictly local. Every step on Mars would be the first ever taken there, something that can no longer be said for virtually anywhere on our "initial" planet. They would do groundbreaking science from the get-go, making discoveries of the caliber that entire careers are made of back on Earth. Who knows? They might even uncover that holy grail of exobiologists—life beyond our world—a find that most would hail as one of the most significant in history.

Compared to human exploratory missions to Mars, which is about 35 million miles away at its closest approach to Earth, Columbus's forays might seem almost provincial. © Ray Roper/iStockphoto

"There will always be people who want to have an opportunity to take part in the creation of something grand and new, to be the creators of their own civilization, not just the inhabitants of one that already exists," Zubrin says. "This would give them that chance." Davies thinks such a mission would serve as a valuable unifying influence for humanity at a difficult time in the 21st century. "A mission like this, I think, would be a wonderful emblem for all of mankind," he says, "something for us to all get behind as a sort of joint project for everybody."

Whoa...

All the glorifying aside, what would settling on Mars actually be like for those who did it? I turned to a man who knows as much as anyone can about that subject—Steve Squyres, the Cornell planetary scientist in charge of the Mars rovers, which have now spent over six years exploring the surface.

"I think what people are not keeping in mind is what a truly horrible place Mars is," Squyres told me. "And you're hearing this from a guy who loves Mars and has devoted his career to trying to explore the place. It's horrifyingly cold. It's dusty. It's bleak. It's barren. It's desolate. And it's incredibly far from home." In short, he takes "a very skeptical view of the whole Mars colonization thing."

Steve Squyres sees Antarctica's research stations, which scientists and support staff visit only temporarily before returning to warmer continents, as models for human stations on Mars. © Ray Roper/iStockphoto

One-way may even be more difficult and more expensive than two, Squyres says. "If you're talking about colonization in the sense that we're establishing a true permanent outpost of civilization on another world, that's a lot harder than a round trip," he says. "The amount of infrastructure, the amount of support that you have to put in place on the surface to sustain people indefinitely, I think may be prohibitively expensive." Altogether, he feels a one-way mission is "totally unrealistic."

Squyres is not against humans going to Mars, nor does he think robots can do as good a job. On the contrary. "The science you can do with robots pales in comparison to what human explorers can do," he says. "I mean, what Spirit and Opportunity have done in six and a half years on Mars, you and I could have done in a good week or 10 days. But you don't need to make them live the rest of their lives and raise their children there in order for them to do the science." For his part, Squyres suspects that eventually we may do with Mars what we've done with Antarctica—establish permanent bases where scientists can go and do research, then rotate out and come home.

"You have to say, 'Look, we're going to Mars in eight years. Let's figure out how to do this.'"

In the end, if there's one thing on which everyone, backers and detractors alike, would agree, it's what a hard sell one-way would be politically. McLane remembers about 10 years ago asking the speaker at a NASA presentation whether the agency was studying one-way missions. "He laughed at me, and ridiculed me, for even suggesting such a thing," McLane says. NASA has never forgotten Kennedy's insistence, in that 1961 speech, on the "one purpose which this nation will never overlook: the survival of the man who first makes this daring flight."

Putting men on the moon took a presidential giant leap. Putting humans on Mars might require the same, Zubrin and others contend. © Ray Roper/iStockphoto

The only way

Ironically, only one step might sway NASA, and perhaps Congress and the American people, to consider one-way: a decision from the top a la Kennedy's of four decades ago. "Every NASA mission design [for Mars] I've ever seen has been a two-way mission, but if there was presidential leadership that redesigned it as a colonization effort, then NASA certainly would do that," Zubrin says. "Really, the way you have to do this is you have to say, 'Look, we're going to Mars in eight years. Let's figure out how to do this.'"

Kennedy himself might have applauded the notion—all save that part about not returning the astronauts safely to the Earth.