Wednesday, December 10, 2008

History







Early conceptions

The first fictional depiction of a satellite being launched into orbit is a short story by Edward Everett Hale, The Brick Moon. The story was serialized in The Atlantic Monthly, starting in 1869. idea surfaces again in Jules Verne's The Begum's Millions (1879).

In 1903 Konstantin Tsiolkovsky (1857–1935) published Исследование мировых пространств реактивными приборами (The Exploration of Cosmic Space by Means of Reaction Devices), which is the first academic treatise on the use of rocketry to launch spacecraft. He calculated the orbital speed required for a minimal orbit around the Earth at 8 km/s, and that a multi-stage rocket fueled by liquid propellants could be used to achieve this. He proposed the use of liquid hydrogen and liquid oxygen, though other combinations can be used.

In 1928 Slovenian Herman Potočnik (1892–1929) published his sole book, Das Problem der Befahrung des Weltraums - der Raketen-Motor (The Problem of Space Travel — The Rocket Motor), a plan for a breakthrough into space and a permanent human presence there. He conceived of a space station in detail and calculated its geostationary orbit. He described the use of orbiting spacecraft for detailed peaceful and military observation of the ground and described how the special conditions of space could be useful for scientific experiments. The book described geostationary satellites (first put forward by Tsiolkovsky) and discussed communication between them and the ground using radio, but fell short of the idea of using satellites for mass broadcasting and as telecommunications relays.

In a 1945 Wireless World article the English science fiction writer Arthur C. Clarke (1917-2008) described in detail the possible use of communications satellites for mass communications. Clarke examined the logistics of satellite launch, possible orbits and other aspects of the creation of a network of world-circling satellites, pointing to the benefits of high-speed global communications. He also suggested that three geostationary satellites would provide coverage over the entire planet.

History of artificial satellites

The first artificial satellite was Sputnik 1, launched by the Soviet Union on 4 October 1957, and that started

the whole Soviet Sputnik program, with Sergei Korolev as chief designer and Kerim Kerimov as his

assistant. This triggered the Space Race between the Soviet Union and the United States.

Sputnik 1 helped to identify the density of high atmospheric layers through measurement of its orbital

change and provided data on radio-signal distribution in the ionosphere. Because the satellite's body was

filled with pressurized nitrogen, Sputnik 1 also provided the first opportunity for meteoroid detection, as a

loss of internal pressure due to meteoroid penetration of the outer surface would have been evident in the

temperature data sent back to Earth. The unanticipated announcement of Sputnik 1's success precipitated

the Sputnik crisis in the United States and ignited the so-called Space Race within the Cold War.

Sputnik 2 was launched on November 3, 1957 and carried the first living passenger into orbit, a dog

named Laika.

In May, 1946, Project RAND had released the Preliminary Design of an Experimental World-Circling

Spaceship, which stated, "A satellite vehicle with appropriate instrumentation can be expected to be one

of the most potent scientific tools of the Twentieth Century. The United States had been considering

launching orbital satellites since 1945 under the Bureau of Aeronautics of the United States Navy. The

United States Air Force's Project RAND eventually released the above report, but did not believe that the

satellite was a potential military weapon; rather, they considered it to be a tool for science, politics, and

propaganda. In 1954, the Secretary of Defense stated, "I know of no American satellite program.

On July 29, 1955, the White House announced that the U.S. intended to launch satellites by the spring of

1958. This became known as Project Vanguard. On July 31, the Soviets announced that they intended to

launch a satellite by the fall of 1957.

Following pressure by the American Rocket Society, the National Science Foundation, and the

International Geophysical Year, military interest picked up and in early 1955 the Air Force and Navy were

working on Project Orbiter, which involved using a Jupiter C rocket to launch a satellite. The project

succeeded, and Explorer 1 became the United States' first satellite on January 31, 1958.

In June 1961, three-and-a-half years after the launch of Sputnik 1, the Air Force used resources of the

United States Space Surveillance Network to catalog 115 Earth-orbiting satellites.

The largest artificial satellite currently orbiting the Earth is the International Space Station.