Right now, six people are living in a nearly windowless, white geodesic dome on the slopes of Hawaii’s Mauna Loa volcano. They sleep in tiny rooms, use no more than eight minutes of shower time a week and subsist on a diet of freeze-dried, canned or preserved food. When they go outside, they exit through a mock air lock, clad head to toe in simulated spacesuits. The dome’s occupants are playing a serious version of the game of pretend — what if we lived on Mars?

Research at the Hawaii Space Exploration Analog and Simulation (HI-SEAS) project, funded in part by NASA, is a continuation of a long history of attempts to understand what will happen to people who travel through outer space for long periods of time. It’s more than a technical problem. Besides multistage rockets to propel a spacecraft out of Earth’s atmosphere, years of planning and precise calculations and massive amounts of fuel, traveling the tens of millions of miles to Mars will take a tremendous amount of time. With current technology, the journey takes more than eight months each way.

Which means that astronauts will get bored. In fact, a number of scientists say that — of all things — boredom is one of the biggest threats to a manned Mars mission, despite the thrill inherent in visiting another planet. And so, attention is being paid to the effects of boredom at HI-SEAS, and on the International Space Station. But because of the causes of chronic boredom, scientists say, research facilities in Antarctica might actually provide a better simulation of the stress of a journey to Mars.

Most living things constantly seek out sensory stimulation — new smells, tastes, sights, sounds or experiences. Even single-celled amoebas will move to investigate new sources of light or heat, says Sheryl Bishop, who studies human performance in extreme environments at the University of Texas Medical Branch. Animals deprived of naturalistic environments and the mental stimulation that come with them can fall into repetitive, harmful patterns of behavior. Anybody of a certain age will remember zoos full of manically pacing tigers, bears gnawing on their metal cages and birds that groomed themselves bald — all a result, we now know, of their rather unstimulating lifestyles.