Space debris began to accumulate in Earth orbit with the launch of the first artificial satellite, Sputnik 1, into orbit in October, 1957. But even before this event, humans might have … See more

Dead spacecraft
In 1958, the United States of America launched Vanguard I into a medium Earth orbit (MEO). As of October 2009 , it, the upper stage of … See more

Tracking from the ground
Radar and optical detectors such as lidar are the main tools for tracking space debris. Although … See more

The issue of space debris has been raised as a mitigation challenge for missions around the Moon with the danger of increasing space debris around it.
It is thought that on 4 … See more

Size and numbers
As of January 2019 there were estimated to be over 128 million pieces of debris smaller than 1 cm (0.39 in), and approximately … See more

To spacecraft
Space junk can be a hazard to active satellites and spacecraft. It has been suggested that Earth orbit could even become impassable … See more

An average of about one tracked object per day has been dropping out of orbit for the past 50 years, averaging almost three objects per day at solar maximum (due to the heating and … See more