Astronauts' year on ISS will be trial for Mars-trip stresses

An American astronaut, along with a Russian cosmonaut, are preparing to become the first to spend an entire year on the International Space Station. It will be a test of endurance for the human body in amicrogravity environment, but also a taste of the psychological challenges that will be faced by future travellers to Mars.

Scott Kelly and Mikhail Kornienko will set off to the station on March 27and remain there until March, 2016.

Kellys identical twin brother Mark, also an astronaut, will be studied on the groundas a comparison for changes in physiology that happen when the force of gravity is taken away for extended periods of time. Without the stress of weight bearing down on them, bones tend to lose calcium, a form of accelerated osteoporosis suffered by the elderly. Fluids shift to the upper body, blood loses red cells, and in some cases, eyesight is affected. Space is actually an unhealthy environment.

These effects have been known for some time and documented by previous astronauts who have done long-duration flights, such as Canadians Bob Thirsk and Chris Hadfield.But their missions were only half-a-year long.

A full year in space has not been done since the 1980s and '90s, when several Russian cosmonauts lived on their space station Mir for more than a year.

The world record holder is Valeri Polyakov who, in 1994, remained in orbit for 437 days. When he returned to Earth, he insisted on walking a short distance away from his capsule to prove the human body could survive that long in space, which was a powerful demonstration of strength and determination.

But Russian scientists were just as interested in the effects that living away from the planet had on his mind.

While visiting the Cosmonaut Training Center outside Moscow in 1995, I sat in on a weekly video conference. The families of the cosmonauts were brought into a roomso they could see and speak to each other for about 15 minutes as Mir passed overhead.At that time, the space station was only contacted when it flew over Russia, and usually only once or twice a day.

The rest of the time, the crew of three were on their own. Living on Mir was a much more isolating experience than the situation today, where the crew of six on the ISS are in contact with the ground almost continuously.

I spoke with the psychiatrist responsible for the mental health of cosmonauts aboard Mir, and he said they took the issue very seriously. After about a year in space, cosmonauts would begin to hit a mental wall, where their work performancewould slow down and degrade. They would spend more time isolated from the other crew members and focus more attention on meals, which were one of the few personal activities available that involved pleasure.

Contact with family members was an important morale booster every week, but the psychiatrist had another tool when the crew began showing signs of depression.

He would ask them who they would like to talk to from the world of arts, entertainment or sports. It might be a famous Russian hockey player, a dancer from the Bolshoi Ballet, or a movie actor; but whomever it was, the psychiatrist would call and ask them to come in for a chat, and the performers always agreed.

The psychological boost from speaking to someone from the outside, who had nothing to do with the space program, was not a member of the family and was someone they admired, kept the crew in good spirits for weeks afterwards.

• Listen to Chris Hadfield on Quirks & Quarks, discussing the challenges of long-duration space missions

The Russians proved that people living in a tin can for prolonged periods of time have serious psychological needs that must be taken care of. And those needs will be amplified on a journey to Mars.

The trip from Earth to the Red Planet takes seven or eight months. Once there, astronauts must remain on the planet for about a year, waiting for the Earth to return to a point in its orbit where the distance for the trip home is at its shortest. Then its another six months coming home.

And during all that time, the delay time talking to Earth can be up to 20 minutes each way, because of the tremendous distance between the two planets. Itmeans direct conversations with people back home will not be possible (at least, not without awkward 40-minute pauses).

Kelly and Kornienko will have better communication with people back home, lots to do during their year on the International Space Station, including spacewalks, and they will be joined by an assortment of international crew members rotating up and back from Earth. They'll have exercise machines to fight off the physical ravages of spaceflight on their bodies. Butthey will also get just a taste of the psychological burden of being isolated from the little aspects of life that are important to us all.

Wish them good luck.