A new network design for the "internet from space"

A new generation of low-flying satellites promises an "internet from space," that will be able to cover even remote regions around the world. Computer scientists at ETH Zurich are proposing a novel network design that could ...

Machine learning & AI

Rainforest preservation through machine learning

Computer scientist David Dao develops intelligent algorithms that use satellite and drone images of rainforests to predict where the next sites of deforestation will be. He will be presenting his research at the climate conference ...


Do you know exactly where you are?

We all rely on GPS to tell us where we are and where we're going. The US government's global network of 30+ satellites guides planes, ships, cars, tractors and much more. The latest GPS systems can provide mm- to cm-accuracy ...

Hi Tech & Innovation

Using artificial intelligence to automate sea-ice charting

Reliable maps of sea-ice conditions and forecasts are of vital importance for maritime safety, safe navigation and planning. The continued retreating and thinning of Arctic sea ice calls for a more effective way of producing ...


Giving smart vehicles their sense of direction

Scientists around the world are racing to develop self-driving vehicles, but a few essential components have yet to be perfected. One is localization—the vehicle's ability to determine its place and motion. Another is mapping—the ...

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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