The European Space Agency (ESA) estimates that there are more than 131,000,000 useless space waste objects, between 1 millimeter and 10 centimeters, currently orbiting around the Earth at an average speed of 36,000 kilometers per hour, which come from different sources such as last stages of rockets, satellites that are no longer operational, and even tools lost in space by astronauts.

Scientific models estimate the total number of space debris objects in Earth orbit to be in the order of:• 29,000 - for sizes larger than 10 cm•             670,000 - for sizes larger than 1 cm•             More than 170 million - for sizes larger than 1 mm.Any of these objects can cause harm to an operational spacecraft.

Space debris by the numbers Number of rocket launches since the start of the space age in 1957 About 6500 (excluding failures) Number of satellites these rocket launches have placed into Earth orbit About 16990 Number of these still in space About 11500

As of January 2019, more than 128 million pieces of debris smaller than 1 cm (0.4 in), about 900,000 pieces of debris 1–10 cm, and around 34,000 of pieces larger than 10 cm (3.9 in) were estimated to be in orbit around the Earth.

The number of tracked pieces of space debris is now over 30 000 The amount of space debris in orbit continues to rise. More than 30 000 pieces of space debris have been recorded and are regularly tracked by space surveillance networks.