Earth Satellite

The artificial objects that circle Earth are called Earth Satelitte. The are launched into space by launch vehicles like space rockets or the space shuttle.  A Satellite can be defined as an artificial orbiting device, such as a communications or weather satellites. The term satellite can also refer to relatively small celestial body such as the Moon that orbits a larger body. The Space Age started in 1957 with the launch of Sputnik. Since then satellites have been designed for a variety of commercial, scientific and military purposes and are circling the Earth.

Satellite Picture

Sputnik Program

The first artificial satellite was Sputnik 1, launched by the Soviet Union on 4 October 1957. This triggered the Space Race between the Soviet Union and the United States. The Soviet Union surprised the world when they launched Sputnik.

The launch of Sputnik had a huge impact on the US and the rest of the Western powers. They realized that if Russia had rockets capable of carrying a satellite into space, they could also deliver nuclear weapons anywhere in the world. American scientists were given top priority on placing an American satellite into space and developing an operational long range missile. Americans became threatened by Soviet accomplishments and as a result the development of space became a national priority.

The Sputnik program consisted of 3 successful satellites that were about 2 ft round and weighed 184 lds, it stayed up for 6 months.
Its rocket booster, weighing 4 tons, also reached orbit and was easily visible from the ground. The second Sputnik satellite was launched on Nov. 3, 1957 and carried a dog, named Laika, into space. The last Sputnik was launched May 15, 1958,and it stayed up for about two years.

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

Types of Satellites

1. Anti-Satellite Weapons (Killer satellites) are satellites designed to destroy "enemy" satellites, other orbital weapons and targets. Some are armed with kinetic rounds, while others use energy and/or particle weapons to destroy satellites, ICBMs, MIRVs. Both the U.S. and the USSR had these satellites.

2. Astronomical Satellites are satellites used for observation of distant planets, galaxies, and other outer space objects.

3. Biosatellites are satellites designed to carry living organisms, generally for scientific experimentation.

4. Communications Satellites are satellites stationed in space for the purpose of telecommunications. Modern communications satellites typically use geosynchronous orbits, Molniya orbits or Low Earth orbits.

5. Miniaturized Satellites are satellites of unusually low weights and small sizes. New classifications are used to categorize these satellites: minisatellite (500200 kg), microsatellite (below 200 kg), nanosatellite (below 10 kg).

6. Navigational Satellites are satellites which use radio time signals transmitted to enable mobile receivers on the ground to determine their exact location. The relatively clear line of sight between the satellites and receivers on the ground, combined with ever-improving electronics, allows satellite navigation systems to measure location to accuracies on the order of a few metres in real time.

7. Reconnaissance Satellites are Earth observation satellite or communications satellite deployed for military or intelligence applications. Little is known about the full power of these satellites, as governments who operate them usually keep information pertaining to their reconnaissance satellites classified.

8. Earth Observation Satellites are satellites intended for non-military uses such as environmental monitoring, meteorology, map making etc.

Orbiting Carbon Observatory - launch 2008

9. Solar Power Satellites are proposed satellites built in high Earth orbit that use microwave power transmission to beam solar power to very large antennae on Earth where it can be used in place of conventional power sources.

10. Space Stations are man-made structures that are designed for human beings to live on in outer space. A space station is distinguished from other manned spacecraft by its lack of major propulsion or landing facilities. Other vehicles are used as transport to and from the station. Space stations are designed for medium-term living in orbit, for periods of weeks, months, or even years.

11. Weather Satellites are satellites that primarily are used to monitor Earth's weather and climate.

Sputnik: First Satellite in Space
Explorer 1: First American Satellite in Space

Interesting Spacecraft:

STEREO spacecraft (Solar TErrestrial RElations Observatory) is the third mission in NASA's Solar Terrestrial Probes program (STP).

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Updated: Tuesday 1st, April, 2014 - Click here to travel right!