Inmarsat's I-4 fleet

This is the first of Inmarsat's 4th generation satellite fleet, was launched in March 2005 and subsequently went into service over the Indian Ocean. This fleet includes two latest generation satellites, the Inmarsat-4s (I-4s), which were launched in 2005. Together, they provide coverage to around 85 per cent of the world's landmass and 98 per cent of the world's population. That dish antenna is 9 meters across, the array of solar panels extend 45 meters. The flap at far left is a "sail", able to "harness pressure exerted by particles from the Sun - the solar wind - to steer the I-4 and fine-tune its orbital position". This bird is already improving existing Inmarsat service in its planet print, and shows its stuff in terms of high speed data.

Inmarsat is also planning to launch a third I-4 satellite in 2008. This will deliver complete mobile broadband coverage of the planet, except for the extreme polar regions. Inmarsat's first wholly owned satellites, the Inmarsat-2s, were launched in the early 1990s, and the Inmarsat-3s - the first generation to use spot beam technology - followed later in the decade.

The total fleet now comprises 10 satellites. The I-4s set a new benchmark for mobile satellite communications in terms of their power, capacity and flexibility. One I-4 satellite is 60 times more powerful than an Inmarsat-3, and the I-4 fleet is expected to have a commercial life until around 2020.