Iridium mobile telephone network. Artwork depicting the types of communications links available through the proposed Iridium satellite system. Iridium is designed to allow personal communications from any part of the world using a simple, portable handset. The handset may connect with existing terrestrial cellular services, satellite-based direct cellular networks or via a dedicated transceiver station. The space segment of the system is a constellation of 66 satellites in low orbits. The satellites are due for launch in 1994-1996. The system is named after the 66th element of the periodic table.