Inmarsat

Inmarsat has stood at the forefront of mobile satellite services for 30 years. They provide voice and high-speed data services to almost anywhere on the planet - on land, at sea and in the air. Inmarsat services are delivered through the most versatile and reliable satellite network in the world.

Satellites

The Inmarsat-4 (I-4) series of satellites are the most advanced commercial mobile communications spacecraft of their kind. The three satellites that make up the global I-4 constellation are part of an 11-strong fleet of spacecraft owned and operated by Inmarsat. All the Inmarsat satellites, including the Inmarsat-2 and Inmarsat-3 generations, fly in geosynchronous orbit 35,786km (22,240 statute miles) above the Earth.

Spot beams

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 I-4s set a new benchmark for mobile satellite communications in terms of their power, capacity and flexibility when they first went into orbit in 2005. One I-4 satellite is 60 times more powerful than an Inmarsat-3. The I-4 series is expected to continue in commercial operation until about 2020.

Alphasat

In the meantime, Inmarsat has entered into agreement with the European Space Agency (ESA) to become the commercial operator of a new satellite called Alphasat. The satellite is part of an ESA initiative to develop a new spacecraft platform capable of carrying a large communications payload. Alphasat is scheduled for completion in 2012 and will supplement the existing I-4 satellites. It will provide service over Europe, the Middle East and Africa.