Chilean engineers have successfully tested the rescue capsule nearly all the way down to where 33 miners have been stranded for nine weeks, hundreds of metres underground.
Lead engineer Andres Sougarett said the empty capsule, known as the Phoenix, descended 610 metres, just 12 metres short of the chamber where the men have been trapped since Aug. 5.
Sougarett said the capsule would be ready to start the rescue operation at midnight Tuesday.
Chilean Mining Minister Laurence Golborne said engineers didn't send the capsule all the way down because they "could risk that someone will jump in."
Golborne said the capsule performed very well in the shaft and did not even loosen any dust.
Earlier Monday, engineers finished installing steel tubing to reinforce the top 90 metres of the shaft that will be used to rescue the men.
Navy Cmdr. Renato Navarro said workers are now installing a platform above the shaft to support the rescue capsule, which will carry the men, one by one, to the surface.
Officials are hopeful the first of the miners can be rescued early Wednesday.
Alberto Iturra, a psychologist with the rescuers, said the first miner should be brought to the surface at dawn because fog often descends on the area at night and the Chilean air force is expected to transport the miners to hospital in the city of Copiapo by helicopter.
A secret list has been made, which states the order that the men will be brought to the surface. The healthiest miners will be rescued first, the weakest last.
Media reports said the miners have been arguing among themselves about who gets to come up last. The Phoenix rescue capsule will take them on a 20-minute ride up the twisting 622-metre shaft.
The men have been put on medication to prevent them from having heart attacks during the strenuous journey.
They will spend at least two days in hospital once they arrive on the surface.
The rescues are expected to be a media spectacle, with about 1,000 journalists now at the San Jose Mine site.
Iturra said he advised the miners' families to return home in order to avoid the growing media presence at the site and to prepare for the arrival of their loved ones.
"They need to get their feet firmly back on the ground as well," he said. "That's why I sent them home to sleep."
Media contracts for exclusive interviews, book and movie deals and other lucrative ventures are expected to greet the men once they restart their lives.
Many will become celebrities, if they so choose. But experts warn that readjusting to their new lives may be difficult.
"Before being heroes, they are victims," University of Santiago psychologist Sergio Gonzalez told The Associated Press. "These people who are coming out of the bottom of the mine are different people ... and their families are too."
Chile's government has promised each of the miners six months of psychological support.
"All of them will have to confront the media and fame, and will encounter families that aren't the same as when they were trapped," Health Minister Jaime Manalich said. "All of them will live through very difficult situations of adaptation."
The men have apparently made a pact not to discuss what happened during the first 17 days following the collapse on the mine. During that time, they had no contact with the outside world and no indication that they could be rescued.
Maria Segovia, who has been waiting for her 48-year-old brother, Dario, to emerge from the mine, said when they meet she'll tell him she's proud of him.
Then she'll give him a "kick his backside," she said, to make sure he never enters a mine again.
With files from The Associated Press
