Communications

Perhaps nothing distinguishes Man from all other creatures as much as his ability and his desire to communicate. Satellite technology, in a few short decades, has radically revolutionised how we communicate.

Making connections

When, in 1945, science fiction writer Arthur C. Clarke published an article in the magazine 'Wireless World' describing the possibility of a global communications network based on three geosynchronous orbit (that is, with the same period of rotation as the Earth), reactions were sceptical, to say the least. No-one at the time could remotely imagine the immense developments in store for space communications.

Today, millions of users around the globe routinely use satellite services for a vast array of applications in work, for leisure, or just to keep in touch. Communications between people that used to take days or even months now take only a few moments or seconds via satellite; television news from remote parts is beamed into our living rooms, colleagues in different countries can hold ‘face-to-face’ videoconferences, journalists can file their copy immediately from abroad, an anthropologist doing fieldwork in deepest Amazonia or a sailor on-board ship on the high sea can call home, students in Africa can access the World Wide Web …

Advantage: satellites

Land-based communications systems have long been hindered by the inherent characteristics of waves, which propagate in a straight line – and since (as we now know!) our Earth is round, and moreover intermittently covered with mountain ranges, this has meant that transmitters need to be as tall as possible (the Eiffel Tower in Paris is one), and operate in conjunction with a large number of relays. Not to mention the cost of laying cable networks, in particular under the sea. Orbiting high above the Earth, a satellite can simultaneously link several ground stations which may be thousands of kilometres apart, and offers immediate, consistent-quality coverage over wide zones, greater flexibility in terms of power and frequencies to adapt to communications requirements in specific areas, and almost complete immunity from events such as hurricanes or earthquakes which could interfere with terrestrial transmissions or damage ground infrastructures.

Satellite systems are essential to bring the benefits of modern communication technology, with all its economic and social impact, to populations in rural or remote locations.