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

Satellites provide crucial data on crops during COVID-19

Millions of people around the world face hunger every day, and unfortunately, the COVID-19 pandemic is expected to make the issue of food security even worse. Satellites are helping to alleviate the situation by providing ...

Brazil firefighters race to contain wetland blazes

A tractor cuts a firebreak through the vegetation of the Pantanal, the world's biggest tropical wetlands, as firefighters race to contain the blazes that have been devastating one of the most biodiverse regions on Earth.

NASA finds an eye and a giant 'tail' in Typhoon Hagupit

NASA-NOAA's Suomi NPP satellite provided forecasters with a visible image of Typhoon Hagupit in the Northwestern Pacific Ocean that showed the development of an eye as it quickly intensified. Imagery also showed a thick band ...

Brazilian Amazon fires surge in July

The number of forest fires in the Brazilian Amazon last month rose 28 percent from July 2019, satellite data showed Saturday, fueling fears the world's biggest rainforest will again be devastated by fires this year.

Monitoring whales from space

Scientists have found that studying high-resolution images of whales from space is a feasible way to estimate their populations. A team, led by British Antarctic Survey (BAS), compared satellite images to data collected from ...

Canadian ice caps disappear, confirming 2017 scientific prediction

The St. Patrick Bay ice caps on the Hazen Plateau of northeastern Ellesmere Island in Nunavut, Canada, have disappeared, according to NASA satellite imagery. National Snow and Ice Data Center (NSIDC) scientists and colleagues ...

New analysis method predicts disruptive solar flares

Solar flares—violent explosions on the surface of the sun—can send blasts of radiation hurtling toward Earth. While the planet's magnetic field protects humans on the surface, powerful solar flares can disable satellites, ...

NASA finds Post-Tropical Low Douglas crossing a line

The strong wind shear that weakened Douglas to a tropical storm early on July 29 has further weakened it to a post-tropical low-pressure area. NASA's Aqua satellite provided an infrared view of those remnants, headed across ...

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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