The explorers communicated with base camp in Montreal in two ways:
1. By telephone
The telephone, weighing 16 kg (including the battery), bounced their messages off an IMMARSAT geostationary satellite 35,000 km above the Equator, to the Montreal base camp. The battery to operate the telephone was rechargeable with solar panels. The antenna was part of the cover of the box for carrying the telephone. All the experts they consulted before leaving predicted that the telephone would not be operable past the 82nd parallel, as the Earth’s curvature would block the signal.
2. By Argos beacon
Bernard and Thierry took along an Argos beacon, which sent a signal every two minutes to two satellites orbiting 8,000 m above the South Pole every 100 minutes. Along with information on their position, the beacon was programmed to provide many other details (physical and psychological condition, type of terrain, km travelled, etc.). After the signal was captured by one of the satellites, it was relayed to Toulouse, France and then retransmitted to Montreal by computer.
Another item in their array of communication equipment was designed to keep the skiers informed of their exact position at every moment:
Global Positioning System (GPS)
This system was based on a network of 24 satellites orbiting the Earth every 12 hours at an altitude of 20,000 km. The explorers’ position was calculated by triangulation, from a signal sent by the device and received by three or more satellites simultaneously. The apparatus was the size of a portable radio.