Why Volunteer for a One-Way Mission to Mars? If NASA put out the word that it was looking for volunteers to suit up for the first manned mission to Mars, the line outside Cape Canaveral might stretch from there to the moon. But what if they said it was a nine-month trip on a cramped spaceship and there was a possibility you wouldn't be coming home? Despite the possibility of those conditions, at least 400 brave souls have said "yes" in response to a new book, "The Human Mission to Mars: Colonizing the Red Planet" (Cosmology Science Publishers). The book is a combined effort of more than 70 scientists, detailing the steps leading up to a successful human mission to the red planet, including all the possible ways in which people would be affected by a lengthy, seven- to nine-month space flight, radiation, zero gravity on their bodies and minds, and how to cope with any viruses or microbes found on Mars. The new book is based on a special edition of the Journal of Cosmology that was edited by Joel S. Levine, a NASA senior research scientist and co-chairman of NASA's Human Exploration of Mars Science Analysis Group. "I have come to view this as one of the greatest adventures in all of human history. When we talk about events of the '60s, number one on the list is the Apollo landing on July 20, 1969," Levine told AOL News from NASA's Langley Research Center in Virginia. "With humans to Mars, I think it's much, much more significant because, for the first time, humans will become a two-planet species -- we'll be on Earth and we'll be on Mars, and it's very exciting." And a big question raised by the scientists is: Would you be willing to take such a trip with the possibility that you won't return home to Earth? "I envision life on Mars to be stunning, frightening, lonely, quite cramped and busy," Peter Greaves told FoxNews.com. Greaves, a family man and motorcycle dispatch company owner, admitted he wouldn't be able to do any of the things he takes for granted on Earth, "but my experience would be so different from all 6 to 7 billion human beings ... that in itself would make up for the things I left behind." But do all the people who sent e-mails volunteering for a trip to Mars truly understand the extreme solitude, isolation and possible depression that could accompany such a historic journey? Pasha Rostov, a 69-year-old computer programmer, wrote: "I do very well with solitude. I am handy with tools, very good at making things work, have generated my own solar energy, built three houses and am quite sane and stable. And I am ready to go to Mars. Sign me up." Levine explained that there are a number of very good reasons for sending humans to Mars, versus sending robotic probes. "One is scientific discovery. In its early history, Mars was very Earth-like, with rivers and lakes, and in fact, most of the northern hemisphere of Mars was covered by oceans several miles thick. "Something happened on Mars to cause catastrophic climate change, and we need to understand that so we can better understand the future of our planet." And the second reason why Levine thinks it's worth any risks to get to Mars involves the question of whether life is unique to Earth. "Most people think the answer is no. But the fact is that we have no evidence of life outside the Earth. And Mars is probably the most likely habitat for life, other than Earth, in our solar system." But what about the problems that any astronaut-colonists might face en route to Mars and then once they arrive? Any volunteers for the trip most likely don't fully understand what they'll have to face. "I suspect most do not. We are really happy that there's so much enthusiasm, but you know, it would be a tough life," said Washington State University astrobiologist Dirk Schulze-Makuch. "It would be challenging in a confined space, first, and once you're on Mars, you'd have more space, but you don't have the convenience and comfort and medical care and everything that you have on Earth," he told AOL News. In the book, "The Human Mission to Mars," Schulze-Makuch co-authored the section titled "To Boldly Go: A One-Way Human Mission to Mars." "It is important to realize that this is not a 'suicide mission.' The astronauts would go to Mars with the intention of staying for the rest of their lives, as trailblazers of a permanent Mars colony," he co-wrote with Arizona State University physicist Paul Davies. They contend that astronauts on Mars would establish a base camp to which more colonists would be sent. "Of course, the life expectancy of the astronauts would be substantially reduced, but that would also be the case for a return mission. "Both risk factors would be halved in a one-way mission, and traded for the rigors of life in a cramped and hostile environment away from sophisticated medical equipment." Schulze-Makuch adds that the adventurous spirit of humans compels us to want to make a difference, "to go into history and to go to places that no one has seen before -- to be the first one there." "We are not on a really safe place in our universe -- just ask the dinosaurs, there aren't anymore. So it would be a big advantage to have two places. Mars can never replace Earth, our home planet where we have adapted. Mars would always be a challenge." While a possible one-way trip to Mars is a daunting possibility, with all of its inherent risks, Schulze-Makuch doesn't think the physical and mental strain would be an important issue for some people who would volunteer to go. "We need to get back to the spirit of American settlers who colonized the country. They came here on little ships and they didn't know what to expect. They were clear that they wouldn't go back anymore, so they had to make a living over here." He also thinks a human mission to Mars would have a tremendous influence on those of us left behind on Earth. "To have a colony on Mars would unify us as a human species, and it would make people realize how valuable life really is, how special we are, that we have a planet with animals and plants. "I believe that, on Mars, there is extraterrestrial life, but it's all bacterial and there isn't anything big there, so it makes Earth so much more special." NASA's Levine says that, with the proper funding, humans could be on the way to Mars within the next 20 years. But he isn't convinced that a mission to Mars involves a no-return ticket. "I don't know if it should be a one-way trip, even though 400 people volunteered for a one-way trip. I think that the American psyche would prefer that we bring these heroes home, healthy and in one piece and then send a crew back two years later." And would he volunteer to go? "To be very honest, my physical and mental ability is better served working for NASA and planning missions rather than going into space, and I'm also too old. But if you'd asked me the same question 30 years ago, I might have given a different answer."