Back to the Future: a look at the Iridium NEXT constellation
The constellation comprises 66 satellites that are operational in orbit, plus a plan for the remaining 15 satellites to serve as a combination of in-orbit and ground spares. Each batch of satellites will replace first-generation Iridium satellites, which will be deorbited after they are replaced. This arrangement ensures service continuity with the first generation, while also providing faster broadband data speeds eventually up to 1.4 megabits per second after the network is completed.
How it works ?
The 66 operational satellites in orbit are divided into six orbital planes, each one containing 11 satellites. The special characteristic of a constellation such as Iridium® is its intersatellite links, which create a mesh architecture. On Iridium NEXT, signals are not routed through a ground network, but rather between the satellites themselves, which are interconnected. Each satellite, in a given plane, is capable of communicating with its four neighboring satellites. Onboard software routes the signals and then directs them to a predefined zone on the ground. Which means that this system does not need substantial investment in various geographic locations for their ground infrastructure, as required by competing “bent pipe” satellite systems. For example, in the extreme case of a major natural disaster that has cut off land-based networks, a person with an Iridium NEXT supported handset can still call for help.
Artistic views: © Thales Alenia Space/Master Image Programmes
Satellite in the clean rooms: © Thales Alenia Space/Imag[IN]
Satellites on the launch pad: © Iridium Communications Inc.