MOSCOW (Reuters) - Four Russians, a Frenchman and a German ended a simulated 105-day space trip in Moscow on Tuesday designed to test their responses in the kind of isolated surroundings they would experience in a manned mission to Mars.

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Stepping out of their sealed compartments in a Moscow scientific complex, the crew members were ending one test just as space agencies step up preparations for a longer 520-day isolation experiment expected to start next year.

The six men were monitored constantly as they responded to physical tests in cramped conditions designed to better understand how humans would cope on a Mars mission, that would take at least 500 days.

All six smiled, waved and put their arms around each other as they emerged into the first sunlight they had seen since March 31 last, giving no indication that any personal animosities developed in the quarantined environment.

“The level of understanding and motivation of the crew was perfect from my point of view as commander,” Russian cosmonaut and scientist Sergei Ryazansky told a news conference at Moscow’s Institute of Medical and Biological Problems.

Roskosmos and European Space Agency tested stress levels for the isolated crew, including the use of a 20-minute delay in contact with the control team, intended to mimic the vast distances radio signals would travel to a distant space craft.

Officials said they would analyze the results to fine-tune both the process for selecting participants in the forthcoming 520-day test and the routine they must endure.

Ryazansky said that when the time delay kicked in, his crew, who wore astronaut-style uniforms, behaved more autonomously.

“Most of the very important decisions were made by the crew itself because the level of communications with ‘Earth’ was definitely not enough to understand every problem, to analyze the reasons for different questions,” he said.

French airline pilot Cyrille Fournier said the time went quickly as they were kept busy. He was now leaving Moscow with five new friends.

“If we realized someone was tired or upset or whatever because of an experiment because of a lack of sleep then we adapted our speech for this crew member,” Fournier said.

“A monotonous regime was applied to us, every minute was full of work. There were some periods in which we could relax, but you cannot really relax, you think about being far from your loved ones, far from your family,” said Alexei Baranov, a medical doctor.

Oliver Knickel, a mechanical engineer in the German army, said national backgrounds made no difference inside the four-linked capsules where they exercised, studied and grew their own vegetables.

“We represent different countries and there are differences in mentalities but very soon we began to see ourselves as one team and we could do everything together, even if there were some differences, of course,” said Knickel.

But since the experiment was based in a Moscow suburb, the participants did not experience zero gravity, ate controlled quantities of normal food - not the toothpaste-style tubes used in space - and knew they could leave in an emergency.