The crew of the French-Italian Concordia research base in the Antarctic saw their last rays of Sun for over four months last weekend. Near the South Pole, the outpost will now continue its research and run self-sufficiently in darkness until September. ESA sponsors a medical research doctor in Concordia every winter to study the long-term effects of isolation and it doesn't come much more isolated than this. The base is 3200 m above sea level and temperatures will drop to -80C.

No supplies can be delivered during the Antarctic winter and nobody can leave the base, no matter what emergency. They have to solve any problems on their own, as a team.

The station is the closest thing on Earth to interplanetary exploration. Studying the effects of isolation there is preparing ESA for the real thing: a mission to Mars.

Science of stress
Oliver Angerer, ESA's coordinator, explains: "The environment is a continuous stress and poses challenges to all the participants involved.

"We are looking at how the crew performs in this harsh environment, in particular regarding sleep. The high altitude at Concordia can already be influencing sleep quality.

"Take away sunlight as well and it becomes even more difficult to maintain normal body rhythms."

With no sunlight, social commitments such as breakfast and dinner become important indicators of when to sleep and when to stay awake.

The ESA-sponsored medical researcher Alexander Kumar is monitoring sleep patterns by recording the brain activity of his sleeping crewmates. He is also taking saliva samples to chart the levels over time of sleep hormones such as melatonin or cortisol.

Cognitive tests similar to commercial brain games are testing crew performance. Will performance drop as the Sun becomes a mere memory?

This year, the study is also following the crew as they exercise to see if it has any effect on morale and sleep patterns.

The crew have a long road ahead of them before they see the Sun again. Follow Concordia and inspire the crew by reading and commenting on their blog. See the links to the right.

ESA is looking for medical doctors to conduct similar research in Concordia next winter. Candidates who are not afraid of the dark can apply before 8 June through the link to the right.