Astronautics, or space exploration , is interdisciplinary because it uses findings in such fields as mathematics , astronomy, physics, medicine , biology, chemistry, electronics, and meteorology. Unmanned and manned space probes have furnished an enormous new source of scientific data on the origin and nature of our solar system and the universe . Earth-orbiting satellites have improved navigational aids, weather forecasting, global communications, and examination of the earth's surface for military purposes and the area of mineral resources. Practical astronautics and the space age began when the USSR launched Sputnik 1 on October 1957 and also when the United States launched Explorer 1 on January 1958. On October 1958 the United States created the National Aeronautics and Space Administration (NASA). Over the next twenty years, over 1600 spacecraft of all varieties have been launched, mostly in Earth’s orbit. Twelve men have walked on the Moon's surface and were able to return to Earth. Around 1986 thousands of objects, mostly inert spacecrafts and space-launch vehicles, were circling the earth.
People have dreamed of spaceflight before it became reality. Confirmation of the dream can be found in Babylonian texts from as far back as 4000 BC. The ancient Greek stories of Icarus and Daedalus also show the desire of flight. In the early 2nd century AD, Lucian , a Greek satirist, wrote about an mythical voyage to the Moon. In the 17th century Johannes Kepler, a German astronomer, wrote Somnium (Sleep), which could possibly be called a scientific satire about a trek to the moon. Voltaire, the French philosopher and writer, in Micromégas (1752), told of the journeys of certain inhabitants of Saturn and Sirius; and in 1865 Jules Verne, the French author, portrayed space travel in one of his popular novels From the Earth to the Moon. The fantasy of space flight continued into the 20th century. The British writer H. G. Wells in 1898 wrote The War of the Worlds and in 1901 The First Men in the Moon. Today, fantasies of space travel have been thriving due to science fiction.