Space debris (also known as space junk, space pollution, or space garbage) is a term for the demise of objects created by man and left in space, mainly on Earth orbit, which no longer serves a useful function.
About Space Debris
This may include malfunctioning spacecraft, abandoned launch vehicle stages, mission-related debris, and fragmentation junk. Examples of space junk include abandoned satellites and spent rocket steps, as well as fragments from their disintegration, erosion, and collisions, such as paint vessels, solidified liquids from spacecraft bursts, loose particles from solid rocket engines, etc. Spatial waste is a risk to spacecraft.
Space debris is usually a negative externality – it creates an external cost for others from the initial action of launching or using a spacecraft in orbit near Earth – a cost that is usually not taken into account and not fully accounted for, at cost by the launcher or the owner of the payload.
Several spacecraft, both equipped and uncrewed, were damaged or destroyed by space debris. Some participants in the space industry perform potential residue measurement, mitigation, and disposal.
The Space Junk Danger
In October 2019, the US Space Surveillance Network reported nearly 20,000 artificial objects in orbit over Earth, including 2,218 operational satellites. However, these are just objects large enough to be tracked.
In January 2019, over 128 million pieces smaller than 1 cm (0.4 in), approximately 900,000 pieces 1-10 cm, and about 34,000 pieces larger than 10 cm were estimated to be in orbit around earth. When the smallest objects of space debris created by humans (paint tips, solid rocket escape particles, etc.) are grouped with micrometeoroids, they are sometimes mentioned together by space agencies under the name of MMOD (micrometeoroids and orbital debris).
Collisions with space junk have become a danger to spacecraft; the smallest objects cause damage similar to blasting, especially solar panels and optics, such as telescopes or stars that cannot be easily protected by a ballistic shield.