Volunteers train on Mauna Loa for the austerities of travel to another planet. Illustration by Emiliano Ponzi

On a clear, cold day in March, 1898, a converted seal-hunting ship named the Belgica gave up struggling against the pack ice of the Bellingshausen Sea and resigned itself to the impending Antarctic winter. The ship was carrying a scientific expedition with an international crew, rare in that phase of polar exploration: nine Belgians, six Norwegians, two Poles, a Romanian, and an American, the ship’s doctor. The expedition’s organizer, a Belgian naval lieutenant named Adrien de Gerlache, had handpicked officers and scientists for their expertise; the mariners who slept in the forecastle had been signed up more casually. None had been selected for character, resilience, or survival instinct. The crew had expected the Belgica to winter over in warmer latitudes. No ship had ever spent a winter locked in the Antarctic ice.

An eerie despondency settled over officers and crew as the days grew short and ice groaned against the hull. Low on coal and lacking proper gear, they sewed winter coats out of blankets. Conversation trailed away, and dinners of tinned meat were greeted with derision. Starting in May, the sun disappeared for two months, and the crew gradually fell apart. A young Belgian geophysicist succumbed to a weak heart, and was buried through a hole in the ice. De Gerlache and the ship’s captain, Georges LeCointe, wrote out their wills and retired to their rooms. One crewman, convinced that the others wanted to kill him, hid away at night, while another tried to leave the ship, announcing plans to walk home to Belgium. Even the ship’s cat withdrew and died. The American doctor, Frederick A. Cook, wrote in his journal that a “spell of indifference” had afflicted him and his shipmates. “Around the tables, in the laboratory, and in the forecastle, men are sitting about sad and dejected, lost in dreams of melancholy,” he noted. “We are at this moment as tired of each other’s company as we are of the cold monotony of the black night and of the unpalatable sameness of our food.”

Cook later became infamous for faking two heroic firsts, the conquest of the North Pole and the ascent of Mt. McKinley. But that winter on the Belgica was an occasion of genuine heroism. Assisted by the ship’s Norwegian first mate, Roald Amundsen, Cook instituted an exercise routine on the ice, walks around the ship known as the “madhouse promenade.” He introduced a “baking treatment” for the men with the lowest morale and the weakest heartbeats, which entailed seating them before the warm glow of the ship’s coal stove. He insisted that the crew start eating the vitamin-rich meat of penguins, which even he described as tasting like a mixture of mammal, fish, and fowl parts, roasted in blood and cod-liver oil. He helped organize entertainments, including a beauty contest among illustrations torn from magazines, with voting categories such as “Alabaster shoulders,” “Supple waist,” and “Irreproachable character.”

With the return of summer, Cook and Amundsen rallied the crew for a monthlong effort to saw a channel to open water. De Gerlache and his men returned to Europe as heroes, and Amundsen—who later achieved renown as a polar explorer—credited the doctor with saving their lives. But the Belgica’s experience became a cautionary tale for the planners of future expeditions to the poles. When Richard Byrd set out, in 1928, to establish a camp in Antarctica, his supplies included two coffins and twelve straitjackets.

A century after the Belgica’s return, a NASA research consultant named Jack Stuster began examining the records of the trip to glean lessons for another kind of expedition: a three-year journey to Mars and back. “Future space expeditions will resemble sea voyages much more than test flights, which have served as the models for all previous space missions,” Stuster wrote in a book, “Bold Endeavors,” which was published in 1996 and quickly became a classic in the space program. A California anthropologist, Stuster had helped design U.S. space stations by studying crew productivity in cases of prolonged isolation and confinement: Antarctic research stations, submarines, the Skylab station. The study of stress in space had never been a big priority at NASA—or of much interest to the stoic astronauts, who worried that psychologists would uncover some hairline crack that might exclude them from future missions. (Russia, by contrast, became the early leader in the field, after being forced to abort several missions because of crew problems.) But in the nineteen-nineties, with planning for the International Space Station nearly complete, NASA scientists turned their attention to journeys deeper into space, and they found questions that had no answers. “That kind of challenging mission was way out of our comfortable low-earth-orbit neighborhood,” Lauren Leveton, the lead scientist of NASA’s Behavioral Health and Performance program, said. Astronauts would be a hundred million miles from home, no longer in close contact with mission control. Staring into the night for eight monotonous months, how would they keep their focus? How would they avoid rancor or debilitating melancholy?

Stuster began studying voyages of discovery—starting with the Niña, the Pinta, and the Santa Maria, whose deployment, he observed, anticipated the NASA-favored principle of “triple redundancy.” Crews united by a special “spirit of the expedition” excelled. He praised the Norwegian Fridtjof Nansen’s three-year journey into the Arctic, launched in 1893, for its planning, its crew selection, and its morale. One icebound Christmas, after a feast of reindeer meat and cranberry jam, Nansen wrote in his journal that people back home were probably worried. “I am afraid their compassion would cool if they could look upon us, hear the merriment that goes on, and see all our comforts and good cheer.” Stuster found that careful attention to habitat design and crew compatibility could avoid psychological and interpersonal problems. He called for windows in spacecraft, noting studies of submarine crewmen who developed temporarily crossed eyes on long missions. (The problem was uncovered when they had an unusual number of automobile accidents on their first days back in port.) He wrote about remote-duty Antarctic posts suffering a kind of insomnia called “polar big eye,” which could be addressed by artificially imposing a diurnal cycle of light and darkness.

“Bold Endeavors” was a hit with astronauts, who carried photocopied pages into space, bearing Stuster’s recommendations on workload, cognitive impairment, and special celebration days. (He nominated the birthday of Jules Verne, whose fictional explorers headed to the moon with fifty gallons of brandy and a “vigorous Newfoundland.”) But historical analogies could take NASA only so far, Stuster argued. Before humans went to Mars, a final test should run astronauts through “high-fidelity mission simulations.” To the extent possible, these tests should be carried out in some remote environment, whose extreme isolation would bring to bear the stress and confinement of a journey to outer space.

One morning in February, I was lurching through lava fields in a white Dodge Ram truck, halfway up Hawaii’s Mauna Loa volcano. Holding tight to the steering wheel, the driver, a University of Hawaii computer-science professor named Kim Binsted, told me that we were climbing the second-biggest mountain in the solar system. Mauna Loa is slightly shorter than its island neighbor Mauna Kea, but it is far more massive, rising gradually from deep below the surface of the Pacific to thirteen thousand six hundred and eighty feet above sea level. Binsted, who had a long side career in improvisational comedy, was soon quibbling with herself about the solar-system ranking—how to score the huge peaks in the Tharsis region of Mars?—but Mauna Loa’s claim is clearly impressive: if Earth were as dry as Mars, the mountain would rise nearly six miles from foot to summit. It is a slow-oozing shield volcano, like its Martian rivals, and the bleak terrain near the summit looks a lot like photographs of rough landscapes beamed from robotic rovers. The Johnson Space Center, in Houston, uses pulverized lava from its slopes to study potential agriculture in space colonies; its iron-rich basalt is a close analogue to the soil on Mars. As Binsted’s mentor, the NASA astrobiologist Chris McKay, put it, “Mauna Loa is our Martian mountain.”