The trapped Chilean miners may face their most severe psychological challenges in a couple of months' time, if experience from space missions is anything to go by.
A recent NASA study suggests rescuers need to be especially vigilant at the halfway stage of the project. It found that the morale of astronauts on the International Space Station declines during the third quarters of their expeditions.
Jack Stuster of Anacapa Sciences in Santa Barbara, California, carried out a systematic analysis of diaries that were kept for this purpose by astronauts during their six-month ISS expeditions. Each of more than 4000 diary entries were categorised as positive, negative or neutral in tone.
Stuster found the strongest overall negative tone in the third quarter of expeditions, a period that has also been said to affect scientists on long stays in the Antarctic. Communications with management deteriorated in the third quarter too, and the frequency of interpersonal problems rose by a fifth.
Other studies have not found the third-quarter effect, however, and suggest that if appropriate measures are taken, the miners need not suffer from it. Earlier studies of psychological issues in space – on the Russian space station Mir in the 1990s (Gravitational and Space Biology Bulletin, vol 14, p 35) and on the ISS (Aviation, Space and Environmental Medicine, vol 78, p 601) – found no evidence of a dip.
"We didn't find that on Mir or the ISS, and it was mainly because of great support the guys got from the ground, both in the US and Russia," said Nick Kanas of the University of California, San Francisco, who helped lead the studies.
By using questionnaires to score the mood and behaviour of crews aboard Mir and the ISS, Kanas's teams showed that constant and high-quality communication and support from the ground is key to helping people cope with long periods of physical isolation.
These and other studies show that maintaining communications, honesty and day-night cycles, and keeping the miners occupied, will be key in the four months it may take to rescue them.
Keep in touch
"One of the main things a crew needs is to be supported from outside and have a goal," says Jennifer Ngo-Anh, project manager of the European Space Agency's ongoing Mars500 experiment, in which six pretend astronauts are spending 500 days in isolation on a mock trip to the Red Planet.
Appointing a colleague as an intermediary on the surface – perhaps a mining foreman or manager – is also important, as that person will already be trusted and respected by the men underground. This has worked well in space exploration, with former astronauts and flight surgeons on the ground serving as first points of liaison with the crews.
It's also vital to keep the miners' families in close and regular touch with the men underground, and to provide the miners with surprise calls and gifts, which on space missions have raised morale hugely.
Tell the truth
There is no point in lying to the men about how long it will take to rescue them. "If they don't give some realistic expectation, the men's anxiety will become acute, especially if nothing seems to be happening," says Sheryl Bishop, a social psychologist at the University of Texas Medical Branch in Galveston, who specialises in human survival in extreme environments. Other psychologists contacted by New Scientist unanimously agreed.
"The best thing is to make sure those men believe they are part of all the decision-making and being kept truthfully in the loop," she says. Also, rescuers should beware of issuing promises they can't meet, as these destroy morale. Estimates of escape time should err on the long side, to avoid dashing hopes of earlier rescue.
Night and day
Studies of astronauts (Aviation, Space and Environmental Medicine, vol 76, p B94) and scientists on long-term Antarctic expeditions (The Lancet, vol 371, p 153) demonstrate the significant and damaging consequences of disrupting day-night cycles. Loss of sleep results in depression, lack of concentration and irritability.
Maintaining a regular sleep-wake cycle will provide the men with milestones and a structure which will make the highly unusual experience seem more normal. "Daylight" could be provided by sending the miners hundreds of light-emitting diodes, which are bright and have very long lifetimes.
Keep busy and get organised
Astronauts have endless tasks and experiments to perform, which keep them constantly occupied – not so the miners. It will be vital to send down sources of entertainment, such as MP3 players, crosswords and reading matter to keep the men occupied.
Even more valuable would be arrangements for the men to adopt a leader – some news reports suggest this has already happened – and to assign tasks to groups of men, giving them a sense that they're contributing to the relief effort themselves. This will increase their self-esteem and morale, and conquer boredom.
"There could, for example, be 10 guys in charge of consumables, another 10 in charge of getting rid of waste, or monitoring information from the surface," says Jason Kring, president of the US Society for Human Performance in Extreme Environments, based in Orlando, Florida. "It's critical because it gives them all something valuable to do."
Stuster even suggests that with an estimated 2 kilometres of tunnels at their disposal, some might be able to carry on prospecting.