On yesterday, Mining Minister Laurence Golborne, reiterated the government's estimate of three to four months to rescue the men, rejecting local reports citing engineers who said it could be done in much less time.
Golborne, wearing a hard hat and standing in front of the bore hole where rescuers first made contact with the men, said that experts had analyzed 10 different methods to get the men out, will continue to study other options, but that "nothing has yet been found that will be quicker."
While it's unclear if the government is simply trying to under-promise and then over-deliver, there is widespread agreement that the major drilling operation is unlikely to endanger the miners.
"If the area where the miners are didn't get crushed in the initial collapse, drilling this new hole isn't going to do that," Walter Veliz Araya, the geologist who was in charge of drilling the three bore holes, told the AP.
Mario Medina Mejia, a Chilean mining engineer not involved in the operation, agrees.
"The question isn't whether they can safely get to the miners," Mejia said. "It's how long can the miners wait for them to arrive?"
Normally, after completing a pilot hole, the opening is enlarged by drilling from the bottom up. The drill, hanging at the bottom of the pilot hole, is reached through existing shafts in a mine and then fitted with the machine cutters, which then blast through rock as they are raised.
In this case, however, there is no way to get those large cutters to the bottom of the mine; if there was a hole large enough to reach it, the men would already have been rescued.
Araya said that knowledge gained drilling the initial holes, which are between 20 and 100 yards (meters) from the shelter, would give the team digging the rescue hole a head start.