|
|
Satellites A satellite is an object that orbits another object (known as its primary). The term is often used to describe an artificial satellite (as opposed to natural satellites, or moons). Originally developed for the military, a set of satellites that constantly broadcast signals down to earth which when received, are used to work out the exact geographical location of the receiver. Not so long ago, satellites were exotic, top-secret devices. They were used primarily in a military capacity, for activities such as navigation and espionage. Now they are an essential part of our daily lives. The Soviet Sputnik satellite was the first to orbit Earth, launched on October 4, 1957. Because of Soviet government secrecy at the time, no photographs were taken of this famous launch. Sputnik was a 23-inch (58-cm), 184-pound (83-kg) metal ball. Although it was a remarkable achievement. On the outside of Sputnik, four whip antennas transmitted on short-wave frequencies above and below what is today's Citizens Band (27 MHz). After 92 days, gravity took over and Sputnik burned in Earth's atmosphere. Thirty days after the Sputnik launch, the dog Laika orbited in a half-ton Sputnik satellite with an air supply for the dog. It burned in the atmosphere in April 1958.
|
