'I'm coming back in, and it's the saddest moment of my life,' said astronaut Ed White during the Gemini 4 mission on 3 June 1965 as he performed the first American spacewalk. What he was experiencing was a profound sensation shared by all later astronauts of seeing Earth from space - a sense of wonder. But research suggests it might also elicit something known as 'the break-off phenomenon' - a feeling of separation from Earth - and it could be a problem for future astronauts going to Mars. Scroll down for video Washington-based Nasa and other agencies will have to cope with mental health issues on missions to Mars. Previously high-altitude pilots have reported a sense of isolation from Earth (stock image shown). This same feeling was once thought to be a problem for Martian explorers
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Washington-based Nasa and other agencies will have to cope with mental health issues on missions to Mars
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Previously high-altitude pilots have reported a sense of isolation from Earth
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This same feeling was once thought to be a problem for Martian explorers
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To cope with the problem many psychological experiments have been carried out over the last few decades
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These include placing people in isolation to cope with being in isolation for so long during a long mission to Mars
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Astronauts are now better taken care of during missions
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And in March 2015 year-long missions will begin on the ISS as a precursor to the 520 days needed for a round-trip Mars mission
It is why Nasa has placed such huge importance on keeping the @placeholder manned since 2000 to test the psychological aspects of space travel.