Humans evolved for life on Earth and when we venture out into the extreme environment of space, things start to get a little strange.
There's the physical toll—simple tasks are a little more complex, bones and muscles weaken, and astronauts even have trouble remembering where they last put their arms and legs. But as space flights get longer, the mental toll of space travel also becomes a concern: how might the stress and conditions of a prolonged mission subtly scramble the brain?
Space travelers are already known to experience include hallucinations, Vaughan Bell writes in the Guardian. Other known problems include crew members acting out and abnormal brain electrical activity.
Most hallucinations are simply a side effect of being in space. "In the early Apollo missions, astronauts reported regular flashes or streaks of light that seemed to come out of nowhere," Bell writes. These mysterious streaks were caused by cosmic rays—tiny particles launched by the explosion of distant stars.
As we consider traveling all the way to Mars, though, problmes like break downs in a crew's communication and spirits are more concerning than a little cosmic ray–induced hallucination.
The trip to Mars could take two to three years, and in her book Packing for Mars: The Curious Science of Life in the Void, Mary Roach writes:
People can’t anticipate how much they’ll miss the natural world until they are deprived of it. I have read about submarine crewmen who haunt the sonar room, listening to whale songs and colonies of snapping shrimp. Submarine captains dispense “periscope liberty”—a chance for crewmembers to gaze at clouds and birds and coastlines and remind themselves that the natural world still exists. I once met a man who told me that after landing in Christchurch after a winter at the South Pole research station, he and his companions spent a couple days just wandering around staring in awe at flowers and trees. At one point, one of them spotted a woman pushing a stroller. “A baby!” he shouted, and they all rushed across the street to see. The woman turned the stroller and ran.
The six men who endured a 520-day simulation of a Mars-bound mission were burdened with boredom and a loss of motivation.
"Four of them showed at least one issue that could have exploded or led to a severe adverse effect during a Mars mission," psychiatrist Mathais Basner from the University of Pennsylvania School of Medicine told Wired. One crew member’s sleep cycle diverged from the rest so much that he spent 20 percent of his time as the only one awake or asleep. Another slept for shorter and shorter periods. A third struggled with depression.
During another simulation, Biosphere 2, two of the crew members never spoke to each other beyond mission-critical exchanges. Their pseudo-silent treatment lasted 18 months, Jane Poynter, one of the crew members, told National Geographic.
At least one issue feared before humans even made it to orbit has not manifested. Freudian psychiatrists speculated that "separation from 'mother Earth' could lead to pathological 'separation anxiety' where 'the temptation to escape through suicide into oblivion may be accompanied by an urge to destroy the space vehicle and the rest of the crew,'" writes Bell.
Perhaps that danger has been avoided due to the selection process prospective crew members face. In any case, it seems smart to continue to confine people to mock capsules and simulate missions as we prepare for the real thing. On October 15, six more people will begin a eight-month simulated NASA mission about 8,000 feet above sea level on the northern slope of Hawai’i’s Mauna Loa.