Satellites - History of Satellites
The idea of "Newton's cannonball" suggests an image of apples being sent flying through the air. In reality, this cannonball is less dramatic, and even less real. Instead, "Newton's cannonball" is the name for the first published mathematical study, which provided the base for the Theory of gravity, and eventually the creation of satellites.
Although Newton's publication was released in 1687, the physical creation of a satellite wasn't attempted for over 200 years. In 1903, the Russian scientist Konstantin Ysiolkovsky performed and published the first calculations required for a satellite to reach, and successfully enter, Earth's orbit. He even suggested the use of a rocket to propel the satellite into space. From this publication, the world was intrigued, and many fictional and other responses were written to entice the development of space technologies. The most notable of these includes a 1928 publication by a Slovenian man named Herman Potocnik. His novel idea was to have a permanent human presence in space, a space station of sorts, which orbited Earth.
It took nearly 50 years from the first calculations, to the successful launch of Sputnik 1 by the Soviet Union on October 4th, 1957. Other than triggering the space race, this satellite was responsible for identifying the utmost atmospheric layers of the Earth. Nearly one month after the successful orbit of Sputnik 1, Sputnik 2 was launched in November 1957. This time, the satellite did not travel alone and was accompanied by a stray dog named Laika. Although Laika did eventually pass away, her presence provided the first evidence that living beings can survive in space.
The United States, in a frantic effort to keep up with the Soviet Union, had multiple satellite projects in development during the late 1950s. Success finally arrived on January 31st, 1958 when Explorer 1 became the first U.S. satellite to begin orbiting the Earth. From this date on, satellites were being sent into Earth's orbit at a rapid pace. By 1961, there were at least 115 Earth-orbiting satellites. Since the 1950s the Space Surveillance Network, controlled by the United States government, has tracked the number and uses of these and other satellites.
Today, the largest, and most well known satellite is that of the International Space Station, launched in 1998. This satellite can hold a crew of six astronauts, and is visible from earth with just the naked eye. Currently, 6,578 satellites have been launched into the Earth's orbit, with the most recent to arrive being the satellite Chang'e 2 on October 1st, 2010. Presently, satellites are responsible for the numerous technologies, including GPS, cell phones, and weather tracking, that are taken for granted today. Therefore, "Newton's cannonball" may not have shot physical apples into space, but today it does shoot texts.