Artificial satellites - a flying spacecraft that orbited the Earth and revolve around it on a geocentric orbit.They are meant for applied and scientific problems.The first launch of an artificial satellite of the Earth occurred October 4, 1957 in the Soviet Union.It was the first artificial celestial body that is created by people.The event was made possible thanks to the results of achievements in many fields of rocket, computers, electronics, celestial mechanics, automatic control, and other fields of science.The first satellite made it possible to measure the density of the upper atmosphere, to verify the accuracy of theoretical calculations and basic technical solutions, which are applied to output satellite into orbit to study the features of a radio transmission in the ionosphere.
America launched its first satellite, "Explorer 1" February 1, 1958, and then, later, produced launches and other countries: France, Australia, Japan, China, United Kingdom.In the field of space research is widespread cooperation between countries around the world.
spacecraft can be called only after the satellite named more than one revolution around the Earth.Otherwise, he is not registered as the satellite and the rocket will be referred to a probe that measured the ballistic trajectory.
satellite is considered active if it is installed radios, flash lamps, which transmits light signals, measuring equipment.Passive satellites often used for observations from the surface of the planet under some scientific tasks.These include satellites cylinders with a diameter up to a few tens of meters.
Artificial satellites are divided into application and research, depending on the tasks they perform.Research studies are designed to celestial bodies, earth, outer space.These are the survey and geophysical satellites orbiting astronomical observatory, etc.Applied satellites - a communication satellites, navigation satellites, weather satellites to study the Earth's resources, technical and others.
artificial satellites designed for manned flight, are called "manned spacecraft satellite".Satellite on a polar orbit circumpolar called polar and equatorial orbit at - equatorial.Stationary satellites - is running on an equatorial circular orbit satellites whose direction coincides with the rotation of the Earth, they still hang over a particular point on the planet.Separated from the satellites orbit at an output to the details, such as fairing, are secondary orbital objects.Often referred to as companions, even though they move along the Earth orbit and are mostly objects for observation for scientific purposes.
From 1957 to 1962.in the name of space objects indicate the year of the launch and the letter of the Greek alphabet corresponding to the serial number run in a given year, as well as the Arabic numeral - number of the object, depending on its scientific value or brightness.But the number of satellites launched grew rapidly, because with January 1, 1963 they have been designated the year start, the number start in the same year and the letter of the alphabet.
satellites may vary in size, design patterns, weight, composition board equipment, depending on the tasks.Energy management apparatus almost all satellites produced by solar panels mounted on the exterior of the housing.
On orbit satellites output by automatically controlled multi-stage rockets.Movement of satellites is subject to passive (pull of the planets, the resistance of Earth's atmosphere, etc.) and active (if installed in the satellite rocket engine) forces.
