9.1 Third-millennium satellites

Through the middle years of the twentieth century most national and international communications were truly wired. Armored copper cables containing up to hundreds of copper wires covered the industrialized countries and crossed oceans beneath the sea. These cables enabled several simultaneous telephone conversations to take place via electromechanically switched exchanges (telephone switching centers), and until well after World War II these cables served communities satisfactorily.

The exception to cables was short-wave high-frequency (HF) radio, but this was unreliable and only enthusiasts (and the military) made any serious use of the medium.

Today satellites are a part of everyday life, with TV delivered this way probably being the most visible aspect for the majority of people. The basic concept of satellite communications has been with us for well over half a century. Things began with Arthur C. Clarke s groundbreaking (space-breaking?) Wireless World paper published in 1945 in which he showed that three satellites placed in geostationary orbit would have footprints covering about 90% of the earth s surface. Geostationary means that the spacecraft s orbits and orbital speeds make them appear stationary with respect to the corresponding point on the earth s surface immediately below the orbiting spacecraft.

Following World War II, European reconstruction and other more fundamentally pressing needs demanded international attention. As a result it was many years before technology reached the point where it became feasible to seriously consider satellite communications as a practical possibility.

In 1957 the Soviets launched the first artificial satellite (Sputnik) and...