Made of 80 percent aircraft-grade aluminum, the sled weighs only 793 pounds, light enough that its crew can drag it across the snow if the terrain gets too rough. The vehicle glides on three Teflon-coated skis, each mounted independently to shocks that can flex more than two feet in case of a particularly brutal bump. "You ride along the snow, and it can be very flat," says Kieron Bradley, the former Formula One engineer who led the CIV team. "All of a sudden, it's four-foot sastrugi" -- irregular snow ridges, cut by the wind, that would sink a regular snowmobile. Once out in front of the pack, the CIV will use ice-penetrating radar to detect crevasses and other hazards in order to map out a route for two six-wheel trucks carrying the rest of the crew and equipment.