The Soviet Union launched Sputnik 1, the first artificial satellite, into orbit in 1957.

A satellite constellation consists of multiple satellites placed in a specific orbit to provide continuous coverage of a particular area.

Geostationary orbit is a type of satellite orbit where the satellite remains above a fixed point on Earth due to its constant altitude and a period of 24 hours.

Low Earth orbit (LEO) satellites are primarily used for Earth observation, providing data and images of the Earth's surface.

The Global Positioning System (GPS) is a satellite system used for global positioning and navigation.

Satellite communication refers to the transfer of data and information between satellites and Earth-based stations.

Direct-to-Home (DTH) broadcasting is a type of satellite communication used for broadcasting television and radio signals directly to homes and businesses.

Military space technology refers to the use of satellites for military purposes, including surveillance, communication, and navigation.

The United States has the largest number of active satellites in orbit.

Space geopolitics is the study of the political, economic, and social implications of space exploration and satellite technology.

The Outer Space Treaty is an international treaty that governs the peaceful use of outer space and celestial bodies.

Space debris refers to the debris left in orbit around Earth, including defunct satellites, rocket boosters, and other objects.

NASA is the space agency responsible for the International Space Station (ISS).

Space exploration is the process of sending a spacecraft to another planet or moon for exploration.

Apollo 11 was the first spacecraft to land on the moon.