Miners facing four-month battle to stay sane and healthy before rescue

A team of doctors and psychiatric experts also arrived at the site in the Chilean desert to help maintain the men's mental and physical health.

"We need to urgently establish what psychological situation they are in. They need to understand what we know up here at the surface: that it will take many weeks for them to reach the light," Health Minister Jaime Manalich explained.

After weeks of mistakes, new cave-ins and other false starts, a drill broke through to the miners' underground refuge on Sunday and came back up carrying two notes with seemingly miraculous news – all 33 were in good condition despite being trapped since August 5.

Engineers worked through the night to reinforce the six-inch-wide bore-hole that broke through to the miners' refuge more than 2,257ft below the surface.

Using a long hose, they coated the walls with a metallic gel to decrease the risk of more rock falls in the unstable mine and make it easier to pass material in capsules nicknamed "palomas," or doves.

The first capsules – which take about an hour to descend from the surface – will include water and food in the form of a high-energy glucose gel to miners who have almost certainly lost significant weight.

Also being sent down are questionnaires to determine each miner's condition, along with medicines and communication equipment to enable them to speak with their families during their long wait.

An enormous machine with diamond-tipped drills capable of carving a person-sized tunnel through solid rock at a rate of about 65ft a day was on its way to the San Jose gold and copper mine outside Copiapo in north-central Chile.

Engineers also were boring two more narrow shafts to the trapped men to ensure that their lifelines would remain intact while the larger tunnel is being carved.