How does it work?
Watch out, traffic jams!
Man’s conquest of space started with Sputnik* 1 in 1957. But only the craziest imagined that a real satellite market would develop. Fifty years later, everyone is pushing and shoving to have “his own’ satellite…
Are satellites outdated?
At the beginning of the 1980’s the appearance of fibre optics made people think that satellites were in for a quiet time. But nothing of the sort. With the appearance of new markets, the growth of the Internet and mobile telephones, deregulation of the communications market that lead to a boom in the number of operators and the need to replace old satellites, the satellite market has exploded. Today about 50 satellites are sent into space each year, as against barely 5 at the beginning of the 1980’s!
Space is very big, and yet…
Certain types of orbit are more in demand than others, especially low orbits (between altitudes of 400 and 1,000 km) and high orbits (often geosynchronous, very useful for communications satellites, at an altitude of 35,700 km). Just a few years ago there were no concerns for these latter ones. Because the higher you go, the greater the circumference available to “position” one’s satellites is: 250,000 km. But that is without counting on the fact that certain orbital windows are more valued than others to cover the areas in question. ITU, the International Telecommunications Union, is responsible for organising and controlling the launch of geostationary satellites: whose turn next?
5,000 or 2,000 satellites
That depends on whether you count those that are operational, or whether you count all those that have been sent into space. Today there are 2,630 satellites active around the Earth. But there are over 7,000 objects, old debris of satellites that have broken up, rocket heads, that are whizzing round at high speed in space, which represent 2,500 tons of metal and several hundred thousand objects of between 1 and 10 cm that can become deadly projectiles for active satellites. The North American Air Defense Command and the French National Centre for Space Studies (CNES)* are responsible for monitoring these mobile dustbins, using specialised telescopes and radars.
