Space exploration is a term which describes searching outer space. There are many reasons for space exploration. The most important reasons are for scientific research and the interest of humans to learn more about outer space. For centuries, humans had dreamt of reaching outer space. Rockets made it possible in the later 20th century. On October 4, 1957, the former Soviet Union launched the Sputnik 1, which was the first artificial satellite. This started the Space Race and people later went into orbit and Americans visited the Moon in Project Apollo.