Deep ice cores are cut with drills hung on cables suspended thousands of meters from the surface. The cable, about the thickness of a pinky finger, is lowered from a tall metal tower. The tip of the drill generally contains cutting blades arranged around the edge of a tube, called the core barrel.

A battery-powered motor at the top of the apparatus turns the barrel, causing the blades to cut the ice. As the blades bite into the ice, the device slowly descends into the glacier and the barrel gradually gets filled up with a cylinder of ice. Three fins at the top of the device push against the walls. Without these parts the motor, rather than the core barrel, would spin around and no ice would be cut.

Chips of ice cut by the blades are swept up by a metal spiral on the outer surface of the barrel. The chips get collected at the back of the equipment and come out the top when the equipment is hauled up.

The ice at the base of the ice sheet below the NGRIP site is unusual because it is near the melting point of water (at the very bottom, there is actually water). When researchers identified the site in the mid-1990s they didn't realize this. And chips cut from warm ice are gummy and harder to clear away. Due to this warm ice, the researchers cut few cores in 2001.

They took off the 2002 season while they figured out what to do. They came back this year with some new tricks. They tried a thermal drill that cuts ice with a heating element. This drill had been designed by a Russian researcher for drilling ice in tropical glaciers which tend to be warmer than polar ice. But, the equipment shorted out several times and the researchers finally abandoned it. Fortunately, they had come up with an alternative approach. A new drill contains a bag filled with a solvent for melting the cutting surface so that it doesn't gum up the drill. The bag, which they call the "cognac bomb" is punctured by a sharp screw when the drill reaches the bottom of the hole.