On June 3, 2010, six men filed through the weedy, Soviet-era campus of the Institute of Biomedical Problems, in Moscow. They made their way past friends, family, scientists, well-wishers and a bronze-toned, gigantic statue of the astronaut Yuri Gagarin before entering a vaulted hall that contained a mock-up of the type of spacecraft that could one day ferry humans to Mars. The men climbed aboard. Behind them, the hatch sealed shut. They didn’t come out for a year and a half.

The Mars500 expedition was the world’s first full-length test of what it would be like for astronauts to travel to and from Mars, which is much farther from Earth than the moon. For five hundred and twenty days, the international crew—three members came from the Russian space agency, two from the European space agency, and one from the Chinese space agency—lived as if they were in flight, eating Russian space food, moving through the capsule’s diminutive rooms via tube-shaped metal hallways, performing scientific experiments to see what was happening to their bodies and their minds, sometimes losing contact with mission control, and only occasionally getting word from their families.

Like real space travellers, they also had lots and lots of downtime. “You basically had to have some projects for yourself,” said the Italian space engineer Diego Urbina, echoing one of the conclusions reached by a raft of scientific papers being published about the project this year.

Born and raised in Colombia, Urbina said that when he heard he had been accepted to take part in Mars500, it sounded like a good opportunity to catch up on some reading. “I like books,” said Urbina, who decided to bring the collected works of Gabriel García Márquez on the simulated Martian voyage. “But usually I don’t have enough time to read.”

While he expected to like Márquez, in the weeks following “takeoff,” Urbina, who recently turned thirty, began to find that the stories were helping him in ways he hadn’t anticipated. “The themes Gabriel García Márquez writes about were very similar to what we were going through,” said Urbina. “He’s talking about loneliness, his stories take place over long periods of time. I felt so identified with the characters.”

He found “The Story of a Shipwrecked Sailor” particularly resonant. “Basically, it’s a guy who just fell off a boat,” explained Urbina, who applied for the Mars500 spot because he hopes to see humans on another planet within his lifetime. “It’s a real story, a journalistic story, it told about how he fell in the sea, his mates all died, he was in a little boat in the middle of the sea. I was reading that at night, everything was silent, I was alone in my three-metre-by-three-metre cabin. It became completely real for me, I could feel myself in the boat, waiting for the sharks and the coast to appear on the horizon.”

Some stories were emotional ballast for him: “As you probably know, we were only guys in the simulator,” he said. “Many of us had significant others outside, some of us had gotten a girlfriend a couple of months before the simulation. One guy had just gotten married. In ‘Love in the Time of Cholera,’ it’s a story of a guy in love with a girl but because of economic reasons she has to marry another guy. So he lives all his life with this platonic love for this girl, and remains so for a whole life. Then the other guy dies, and when they’re really old they get back together. A year and a half is long, but this is a whole lifetime! And there’s a little bit of hope at the end.”

The books’ renderings of the natural world helped make the physical reality of living inside the five-hundred-and-fifty-cubic-metre capsule more bearable. “When we were in there, we had sensory deprivation,” said Urbina. “We couldn’t smell the nature or see the nature. We couldn’t interact with the people close to us. Gabriel García Márquez’s books are rich in description—then there’s this magical realism, this magical look at the world of nature.”

Not everyone turned to literature. While the Russian researcher Alexander Smoleevskiy did bring a copy of “War and Peace,” he said that he failed, yet again, to get into it (instead, Smoleevskiy, a military physician and who says he still sometimes misses his time in the simulator, read a medical textbook cover to cover). The Chinese astronaut trainer Wang Yue (dubbed “Vanya” by his Russian colleagues) practiced calligraphy. Each man tried to learn a colleague’s language, with varying degrees of success; in addition to playing video games, favorite pastimes included describing, in great detail, each country’s most delicious foods.

“Everyone had their own coping mechanism,” said Urbina.

After pretending to land on Mars halfway through into the mission, Urbina, Smoleevskiy, and Wang simulated a surface exploration (“Mars” was a corrugated-steel shack upstairs from the spacecraft, with a sand floor, black walls, pinprick ‘stars,’ and a strand of red café lights). “This was really exciting,” said Urbina, who was then about midway through the fiction he had brought. “It felt weird, like I was doing the real thing. My mind was in this mode, like we were really on Mars. I felt really far from everything, from the whole world. Like in some kind of parallel universe.”

The return to Earth was the most difficult part of the trip, he said. Mars had been explored, the eight months that remained before he could see his family stretched ahead, and the days were taken up by only relatively monotonous tasks. To get some perspective on his situation, he read Márquez’s “News of a Kidnapping”; John McCain’s memoir, “Faith of My Fathers” (particularly the part that dealt with the five-plus years that McCain spent as a prisoner of war); and Sebastian Junger’s “War.” (He also read “2001: A Space Odyssey,” by Arthur C. Clarke, and appreciated the book’s slow pace, which he said he would have found tedious before his expedition).

While he usually averages two books a year, in the course of the Mars500 experiment Urbina read twenty-seven. “That was really important for me,” he said. “In the end, what you are doing, it’s really cold, really repetitive. You need to stay in touch with your humanity. Books are a really good tool for that.”

Sally McGrane is a journalist based in Berlin.

Above: The wardroom in the Mars500 spacecraft. Photograph by Valeriy Melnikov/RIA Novosti/Redux.