Invention of Artificial Satellites- Sputnik 1 at October, 1957
“Sputnik 1 (The first Invention of Artificial Satellite) fascinated and frightened vast numbers of people.” By Don Mitchell, “Sputnik: 50 Years Ago”
Sputnik 1 was the first artificial Earth satellite. The Soviet Union launched the first artificial satellite, Sputnik 1, on October, 1957, thus triggering the space race with the United States.
Sputnik itself provided scientists with valuable information, even though it was not equipped with scientific instruments. The density of the upper atmosphere could be deduced from its drag on the orbit, and the propagation of its radio signals gave information about the ionosphere. Sputnik 1 was a nitrogen-filled sphere about the size of a beach ball-23 inched (58cm) across-which orbited the Earth every ninety-six minutes. It had four long, whip like aerials that transmitted information back to Earth. In November the year, Sputnik 2 carried a living passenger, the dog Laika, into space. (It is thought that Laika only survived a few hours rather than the intended ten days because of stress and overheating.) By August 1960, when Sputnik 5 was launched two dogs, forty mice, two rats, and a collection of plants had been sent into orbit. The goal was the manned exploration of space.
The United States were taken horribly by surprise by the Soviets achievement and responded by pumping money into space research and founding NASA, the National Aeronautics and Space Administration. Soon near-Earth space was being crisscrossed by a variety of artificial satellites.
Around 40 countries have since manufactured and launched their own artificial satellites. About 3,000 useful satellites are thought to be orbiting Earth, along with 6,000 pieces of ‘space junk’ (such a empty fuel tanks and rocket boosters). Although artificial satellites have orbited the moon, the sun, asteroids, and planets, most are operated orbiting the Earth. They are used to study the universe, forecast weather, transmit telephone calls and television broadcast, and assist in sea and air navigation as well as military activities.