Rescuers could free 33 miners weeks earlier than expected as drills work around the clock to bore an escape shaft to the men trapped underground for 47 days.
Rapid progress by three drills has improved the chances of reaching the miners in October instead of November as first thought, a senior official in the challenging rescue operation told Reuters on Tuesday.
The men have been trapped in a copper and gold mine 2,300 feet below Chile's arid Atacama desert since it caved in on August 5.
Their fight for survival has captivated the attention of the Chilean nation and drawn support from foreign presidents, Pope Benedict and World Cup soccer stars.
"It is likely that the rescue operation will take place in October if we have no delays," said the official, who asked not to be named because he was not allow to speak publicly.
Relatives said they are confident the miners will be back on the surface in early October, but worry about their mental health after spending weeks in the dimly-lit and hot tunnel.
"I want to take him home as soon as possible," said Alicia Campos, mother of trapped miner Daniel Herrera. "But I fear he will not come out of the mine the same person who went in."
Chile's government brought in a team of NASA experts and submariners for advice on how to keep the miners mentally and physically fit during their prolonged confinement in the dark.
Rescuers are in contact with the miners down several small ducts through which they deliver food and water, letters from relatives and even soccer videos.
The men were in high spirits on the weekend when they cheered and clapped as they watched celebrations of the 200th anniversary of Chile's independence on a small video projector linked to the surface by optic fiber cable. They watched singers perform for their relatives near the mine.
Rescuers also lowered them traditional meat pies and soda -- a reprieve from a strict diet aimed at keeping the men healthy, but thin enough to fit through the rescue shaft.
The miners, who range from a former professional soccer player to a first-time miner and a Bolivian immigrant, have exchanged letters and videos with their relatives -- including images of the birth of the daughter of one of them.
The miners keep busy clearing away debris that falls into the mine as the drill bores through the earth above them.
The Chilean Navy is building rescue capsules -- dubbed the "Phoenix" for the mythical bird that rises from its ashes -- that will be used to winch the men to the surface one by one after the bore hole diameter is widened to 28 inches.