Related topics: nasa , launch , space
Satellite
hideIn the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavor. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon.
The first artificial satellite, Sputnik 1, was launched by the Soviet Union in 1957. By 2009 thousands of satellites have been launched into orbit around the Earth. These originate from more than 50 countries and have used the satellite launching capabilities of ten nations. A few hundred satellites are currently operational, whereas thousands of unused satellites and satellite fragments orbit the Earth as space debris. A few space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Venus, Mars, Jupiter and Saturn.
Satellites are used for a large number of purposes. Common types include military (spy) and civilian Earth observation satellites, communication satellites, navigation satellites, weather satellites, and research satellites. Space stations and human spacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, and are classified in a number of ways. Well-known (overlapping) classes include low Earth orbit, polar orbit, and geostationary orbit.
Satellites are usually semi-independent computer controlled systems. Satellite subsystems attend many tasks, such as power generation, thermal control, telemetry, attitude control and orbit control.
For more information about Satellite, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with satellite
Statistics experts reject global cooling claims
Space & Earth / Earth Sciences
Oct 26, 2009 |
4.6 / 5 (92) |
23
(AP) -- Have you heard that the world is now cooling instead of warming? You may have seen some news reports on the Internet or heard about it from a provocative new book.
The least sea ice in 800 years
Space & Earth / Earth Sciences
Jul 01, 2009 |
4.1 / 5 (66) |
77
New research, which reconstructs the extent of ice in the sea between Greenland and Svalbard from the 13th century to the present indicates that there has never been so little sea ice as there is now. The ...
Study shows strong evidence that cloud changes may exacerbate global warming
Space & Earth / Earth Sciences
Jul 23, 2009 |
4.4 / 5 (56) |
15
The role of clouds in climate change has been a major question for decades. As the earth warms under increasing greenhouse gases, it is not known whether clouds will dissipate, letting in more of the sun's ...
Dark Energy From the Ground Up: Make Way for BigBOSS
Aug 07, 2009 |
4.9 / 5 (36) |
13
(PhysOrg.com) -- Several ways have been proposed to examine dark energy, in hopes of finding out just what it is. One of them, "supernovae" for short, certainly works: it's how dark energy was discovered in ...
Researchers create smaller and more efficient nuclear battery
Oct 07, 2009 |
4.8 / 5 (27) |
14
(PhysOrg.com) -- Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are ...
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Greenland ice cap melting faster than ever
Space & Earth / Earth Sciences
Nov 12, 2009 |
3.6 / 5 (32) |
25
Satellite observations and a state-of-the art regional atmospheric model have independently confirmed that the Greenland ice sheet is loosing mass at an accelerating rate, reports a new study in Science.
The Stars My Destination
Space & Earth / Space Exploration
Nov 10, 2009 |
4.8 / 5 (23) |
2
The Voyager spacecraft are now in the outermost layer of the heliosphere, traveling toward interstellar space - the first man-made spacecraft to travel such a vast distance from Earth.
Eastern Aral Sea has shrunk by 80% since 2006: ESA
Jul 10, 2009 |
4.7 / 5 (20) |
3
The eastern lobe of the disaster-struck Aral Sea seems to have shrunk by four-fifths in just three years, the European Space Agency (ESA) said on Friday.
Astrophysicists solve mystery in Milky Way galaxy
Jul 09, 2009 |
4.7 / 5 (19) |
7
A team of astrophysicists has solved a mystery that led some scientists to speculate that the distribution of certain gamma rays in our Milky Way galaxy was evidence of a form of undetectable "dark matter" ...
Solar Mystery Solved
Aug 26, 2009 |
4.3 / 5 (19) |
8
(PhysOrg.com) -- Solar flares are amongst the most dangerous cosmic phenomena man has ever known. Though they pose no harm to humans, their effect on technology is vast. When they occur, they possess the capability ...
A solution to Darwin's 'mystery of the mysteries' emerges from the dark matter of the genome
Oct 26, 2009 |
4.2 / 5 (14) |
0
Biological species are often defined on the basis of reproductive isolation. Ever since Darwin pointed out his difficulty in explaining why crosses between two species often yield sterile or inviable progeny (for instance, ...
Is the Milky Way doomed to be destroyed by galactic bombardment? Probably not
Aug 31, 2009 |
4.3 / 5 (12) |
2
(PhysOrg.com) -- As scientists attempt to learn more about how galaxies evolve, an open question has been whether collisions with our dwarf galactic neighbors will one day tear apart the disk of the Milky ...
GOCE delivering data for best gravity map ever (w/ Video)
Space & Earth / Space Exploration
Sep 30, 2009 |
4.8 / 5 (10) |
3
(PhysOrg.com) -- Following the launch and in-orbit testing of the most sophisticated gravity mission ever built, ESA’s GOCE satellite is now in ‘measurement mode’, mapping tiny variations in Earth’s gravity ...
From ecological Soviet-era ruin, a sea is reborn
Oct 25, 2009 |
4.4 / 5 (11) |
3
(AP) -- Standing on the shore under the relentless Central Asian sun, Badarkhan Prikeyev drew on a cigarette and squinted into the distance as one fishing boat after another returned with the day's catch.
India loses communication with lunar satellite (Update)
Space & Earth / Space Exploration
Aug 30, 2009 |
3.8 / 5 (12) |
18
(AP) -- India's national space agency said communications with the country's only satellite orbiting the moon snapped Saturday and that its scientists were no longer controlling the spacecraft.
