On Months-Long Missions, How Durable Is An Astronaut's Mind?

As an international team of volunteers in Russia approaches the three-month mark in its ambitious simulation of a 520-day flight to Mars, researchers are keeping a close watch on how the six men are physically and psychologically coping.

The Mars500 project began June 3 with three Russians, two Europeans and one Chinese participant sealed inside a Mars spaceship simulator at Russia's Institute for Biomedical Problems in Moscow.

By meticulously practicing every step of a mission to the Red Planet, the volunteers are giving scientists a close look at the psychological effects of long-duration spaceflight. [Graphic: Inside the Mars500 simulator.]

As NASA sets its sights on eventual missions to an asteroid and Mars, it is crucial to understand the physical and mental toll these voyages would take, scientists have said.

"This simulated Mars mission is by far the longest-duration study of crew confinement under operating conditions attempted to date," said David Dinges, who is leading the only American study in the Mars500 project, a joint experiment by Russia, China and the European Space Agency. "It will have an impact on planning for exploration missions." Dinges is a psychology professor at the University of Pennsylvania.

In addition to their daily routine of experiments and chores, the mock astronauts have found ways to keep themselves busy. That included running a small betting pool on which national soccer team would win the World Cup.

"Well, as is usual on Earth, we decided to run a small gamble on the World Cup," Diego Urbina, one of the participants, wrote in a blog post. "It was all fun and games until we got a winner and realized that we had nothing to pay him with."

One long trip for humankind

The longest anyone has spent in space on a single mission is 438 days. That record was set in 1995 by Russian cosmonaut Valery Polyakov on the Mir space station. A mission to Mars would take months longer.

"We think we understand a lot of the factors that have to do with long-term isolation in space," Nick Kanas, a professor of psychiatry at the University of California, San Francisco, told SPACE.com. "But the problem with Mars is that new factors are entering in because of time delays and issues of autonomy. These are novel ? it's time to look at what these additional factors mean for a Mars trip."

Kanas has conducted extensive research on the psychological factors that affect crew members aboard the International Space Station and their corresponding mission control personnel on Earth.

Kanas and his team have studied crews that spent four to seven months isolated on the space station. The researchers primarily have looked at four areas: changes in group dynamics, displacement of tension, cultural factors, and the presence or absence of a "third-quarter effect" ? an effect of elapsed time that would become apparent just past the midpoint of the mission.

"The bottom line is that we did not find any effects of time," Kanas said. "Statistically, one quarter looked like another quarter."

A third-quarter effect would have been characterized by a dip in morale, an increase in depression or tension. Researchers believe this phenomenon can occur halfway through a mission as a culmination of being in a stressful, isolated environment for so long.

"It's a reaction that leads to a letdown," Kanas explained. "You do something stressful and you get to the halfway point, and then you suddenly realize that you have another half to go. But we didn't find that. We think we didn't find it in our studies because there is a tremendous support network that occurs between the crew members and ground personnel."

Some researchers have observed the effect in other studies, however.

Mars morale meltdown

Gro Sandal, a principal investigator for the 520-day Mars500 simulation and a professor of psychology at the University of Bergen in Norway, has conducted several studies on crew isolation and autonomy. She reported that changes in crew member morale became evident at the middle phase of the confinement.

"We have seen that in this period of time, the motivation of crew members seems to be at the lowest point," Sandal told SPACE.com.

Noting that some studies did not find such an effect, Sandal said this discrepancy is probably due to the different settings and mission characteristics involved in the experiments.

Fighting boredom in space

Kanas and Sandal agree that maintaining crew morale through the halfway point of a mission and beyond is largely contingent upon minimizing monotony and boredom.

For shorter missions, this can be done by sending surprise presents to the crew ? such as food or other treats on support ships ? or by arranging telephone calls with their families or favorite movie stars.

Such steps would help to keep the crew's spirits high. But for a long-duration spaceflight like a mission to Mars, they would become far more complicated, if not impossible.

"A lot of these countermeasures will not be available to people going to Mars," Kanas said. "There will be a tremendous time delay ? up to 44 minutes round trip. So if you ask a question from Mars and the planet is on the other side of the sun, you're going to have to wait 44 minutes or so to get an answer from ground personnel on Earth."

This will certainly require changes to how crews communicate with mission control and how problems are dealt with.

"You have to anticipate delays and come up with a strategy," Kanas explained. "You can't send up a surprise present because it's going to take six to eight months to get there. Plus the crews will be very autonomous. They won't be getting their schedules every day, so they'll be planning a lot of their own daily schedules."

Mars crew dynamics

The Mars500 experiment is a unique opportunity for researchers to observe some of these dynamics, researchers said.

"The autonomy and isolation of the crew will have an impact on psychological parameters," Sandal said. "During a mission to Mars, the crew will not be able to rely on the same level of support from Earth as, for example, during ISS missions. So the crew's isolation is going to be much stronger, and this, in combination with the longer duration and lack of continuous support from Earth, will be an important aspect which will be simulated during Mars500."

Researchers are also hoping Mars500 sheds light on what factors to consider in selecting crews for future long-duration missions. When the voyage itself could last several years, crew composition becomes an integral part of the mission's success.

• Gallery- Mars Base of the Future
• The Best and Worst Mars Landings Ever
• Video - How European Astronauts May Go to Mars

This report is the first in a two-part series on long-duration spaceflight that examines some of the major issues that will be studied throughout the Mars500 simulation. Part Two discusses the importance of crew selection.