Satellites are tracked by United States Space Surveillance Network (SSN), which has been tracking every object in orbit over 10 cm in diameter since it was founded in 1957. There are approximately 560 satellites operating in Earth orbit, out of ~8,000 man-made objects in total. In its entire history, the SSN has tracked more than 26,000 space objects orbiting Earth. The majority of these have fallen into unstable orbits and incinerated during reentry. The SSN also keeps track which piece of space junk belongs to which country.

The SSN was founded in the wake of the launch of Sputnik, the first artificial satellite, by the Soviet Union in October 1957. Orbiting the planet at 20,000 mph while emitting a constant radio signal, Sputnik was a red flag that told America not to take its technological dominance for granted. In the following decade, the Space Race between the USSR and USA occurred, ending with Apollo landing in July 1969.

As space technology matured, satellites were launched for military and commercial purposes, and the price of satellite launches came down as far as a few million dollars for light satellites, and a few tens of millions for heavy satellites. This put satellite technology within the reach of many nations and international companies. The current lowest possible cost per kilogram of payload for space launches is about $4,000 USD/kg.

Satellites have an operating lifespan between five and twenty years. Currently, the former Soviet states launch about 1,300 satellites into orbit per year, the USA about 1,000, Japan 100, China 50, France 40, India 30, the UK 25, and a few from Australia and Israel. The company Sea Launch — a consortium of four companies from the United States, Russia, Ukraine and Norway — launches a few satellites into orbit from international waters every year.

The largest satellite currently in orbit around the Earth is the International Space Station. Some satellites, called microsats, nanosats, or picosats, can be as small as 10 cm in diameter and 0.1 kg in mass.