Global broadband

Last Friday, Inmarsat’s I-4 satellite was successfully sent into space from Cape Canaveral, FL on board an Atlas V rocket.

The size of a London double-decker bus and weighing about six tons, the I-4 will deliver a 3G-compatible broadband data service to mobile users. The satellite is 60 times more powerful, and has 20 times more capacity than its predecessors, the Inmarsat-3 satellites.

The satellite will now undergo a complex series of post-launch tests and manoeuvres before being fully deployed in geostationary orbit, 36,000km above the Indian Ocean at 64 degrees east. The satellite footprint will cover Europe, Africa, the Middle East, the Indian sub-continent, most of Asia Pacific, and Western Australia.

The main body of the new satellite was constructed in Britain. The bus, the onboard rocket engine that positions the spacecraft in orbit (also known as the service module), was built at the EADS Astrium facility in Stevenage. The payload - the satellite's communications powerhouse - was assembled at the company's facility in Portsmouth.

The other main elements of the spacecraft - the antenna, the solar arrays and the 9m reflector - were manufactured in Canada, Germany, and the USA and transported to the EADS Astrium facility in Toulouse, France, for integration with the bus and payload.

Inmarsat currently intends to launch a second I-4 satellite in the third quarter of 2005, which will be located over the Atlantic Ocean at 53 degrees west and provide service for the Americas. The two I-4 satellites will then cover 85% of the world's land mass.

When the two satellites are fully operational, currently expected in the fourth quarter of 2005, Inmarsat intends to launch its new Broadband Global Area Network (BGAN) service. BGAN is an IP and circuit-switched service that will offer voice telephony and a range of high-bandwidth services, including Internet access, videoconferencing, LAN and other services, at speeds of up to 432kbit/sec.