uydu

Uydu, in Turkish, means satellite. It refers to any object placed in orbit around a planet or another body, and can describe natural satellites as well as artificial, human-made ones. In space science and technology, satellites serve purposes such as communication, Earth observation, navigation, and scientific research.

Natural satellites are celestial bodies that orbit planets. The most familiar example is Earth's Moon. Other planets host various natural satellites, ranging from small irregular moons to larger, geologically diverse bodies.

Artificial satellites are engineered and launched by rockets to achieve specific orbits. They operate under ground control and transmit data back to Earth. Major application areas include communications and broadcasting, weather observation, navigation and positioning, Earth imaging, scientific experiments, and military uses. Orbits are commonly categorized as Low Earth Orbit (LEO), up to about 2000 kilometers above Earth; Medium Earth Orbit (MEO); Geostationary Orbit (GEO) at about 35,786 kilometers, where a satellite remains fixed relative to the surface; and Highly Elliptical Orbits (HEO) for extended visibility over particular regions. Many modern systems operate in constellations to provide continuous coverage.

End of life for satellites involves deorbiting or moving to a designated graveyard orbit, to reduce space debris and collision risk. The satellite industry is global, with national space agencies, commercial operators, and international cooperation guided by space law and policy frameworks, such as the Outer Space Treaty. In Turkey, the term uydu is widely used, and Türksat operates Turkish communication satellites as part of the national space program.