Nasa experts head to Chile mine to help miners
Experts from the US space agency Nasa are travelling to a copper mine in Chile where 33 miners have been trapped underground for almost a month.
The specialists will advise the Chilean government on how to keep the miners in good spirits under extreme conditions.
Nasa's deputy chief medical officer Michael Duncan has already told Chilean officials to be frank with the miners about how long their rescue will take.
Drilling work to rescue the miners could take three to four months.
The miners have been told it could take a long time to get them out of the San Jose mine, in Copiapo, but have not been given dates.
On Tuesday, the company that owns the mine asked for forgiveness from the miners' relatives, many of whom have accused it of ignoring safety guidelines.
The firm denies the accusations, but described the unfolding drama at the San Jose mine as "a terrible situation".
The Nasa team, made up of a doctor, a nutritionist, an engineer and a psychologist, has considerable experience of space missions and is used to helping astronauts cope with extreme conditions and months of solitude.
Mr Duncan, who is leading the Nasa team in Chile, said his group had been asked to provide help in nutrition and behavioural health.
Speaking at a news conference in Santiago before travelling to the mine, he said his team had seen two videos the miners made of themselves, and that a priority was increasing the miners' caloric intake, getting them on a regular sleep schedule and ensuring they remain optimistic.
"These miners showed us tremendous strength in surviving as long as they did without any contact with the surface," he said. "What we want to try to avoid is any kind of situation of hopelessness."
Head doctor Jorge Diaz Anay said the miners no longer had any nutritional deficiencies.
"We have finished the process of nutritional stabilising and recuperation. And from tomorrow morning we begin regular nutritional maintenance," he said on Tuesday.
The miners, stuck 700m (2,300ft) below ground since 5 August, have been eating high protein drinks and dietary supplements.
New video footage of the men was shown on Chilean state television on Tuesday, in which they appeared healthier and more cheerful than in previous videos.
While the rescuers attempt to drill down to the men, there is also concern for their colleagues up above who escaped the rock collapse but who have not been able to work for nearly a month.
The San Esteban mining firm paid their wages until the end of August, but is rumoured to be on the verge of bankruptcy. The government says it is helping the miners to find new jobs.
Last week, a Chilean judge ordered the freezing of $1.8bn (£1.2bn) in assets owned by San Esteban, to cater for compensation claims by the miners' families.
How rescuers will drill to save miners
1. First, a 33cm pilot hole is drilled down to the miners' location
2. Next, the hole is "reamed" with a wider drill to a diameter of between 60 and 70cm. Debris falls down the hole to the bottom
3. Thirdly, a rescue capsule is lowered down to the men and each is slowly brought to the surface