News tagged with satellite

Related topics: nasa , space , launch , earth , orbit

New muscle power from the lab

(Medical Xpress)—Unlike the heart muscle, the musculature of the locomotive organs has the capacity to heal itself. What makes this possible are muscle-specific stem cells known as satellite cells. Located ...

Aug 19, 2013
popularity 5 / 5 (2) | comments 0 | with audio podcast

Suburban green thumb denotes healthier residents

(Medical Xpress)—A first ever study by the University of Western Australia and Yale University has examined the relationship between neighbourhood greenness and weight status using satellite remote sensing.

Aug 12, 2013
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Possible muscle disease therapeutic target found

The study of muscular system protein myostatin has been of great interest to researchers as a potential therapeutic target for people with muscular disorders. Although much is known about how myostatin affects muscle growth, ...

Aug 06, 2012
popularity 5 / 5 (2) | comments 0 | with audio podcast

Satellite

In 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.

This text uses material from Wikipedia licensed under CC BY-SA