The Chilean mine rescue team has successfully tested a rescue capsule nearly all the way down to where the miners are trapped.
Leader Andres Sougarett said the empty capsule descended 2,000 feet, just 46 feet short of the chamber where 33 miners have been trapped since an August 5 collapse.
He said all would be in place at midnight local time on Tuesday night to begin the rescue.
The steel capsule was lowered by winch into the hole after its top 295 feet were encased in tubing.
"We didn't send it (all the way) down because we could risk that someone will jump in," Mr Golborne said. He called the test "very promising, very positive" and said the capsule, the biggest of three built by Chilean Navy engineers, "performed very well in the duct."
A tentative but secret list has been drafted regarding which miners should come out first when the extraction begins.
Two paramedics will be sent down to oversee the rescue, and will be relieved 12 hours later by another two paramedics, said Rene Aguilar, the deputy rescue chief.
One by one they will take a twisting, 20-minute ride for 2,041 feet up to the rock-strewn desert. The capsule is expected to rotate 350 degrees 10 to 12 times through curves in the escape hole on its way up. It should take about an hour for the rescue capsule to make a round trip.
Chile's government has promised each miner at least six months of psychological support.
The miners have had the support of a team of psychologists while underground, but that was designed mostly to help them endure the extreme conditions. Last week, they also got an hour a day of training in dealing with the media, including practice with "ugly, bad and indiscreet" questions about their time underground, their personal lives and their families.