Woah… Let’s get those automated space cleanup satellites and lasers going before this becomes a real problem! TL;DR: space debris might compound and prevent launching new satellites.
For the first time since the 1960s it’s beginning to look as if human activity beyond low earth orbit is a distinct possibility within the next decade.
But there’s a fly in the ointment.
Kessler Syndrome, or collisional cascading, is a nightmare scenario for space activity. Proposed by NASA scientist Donald Kessler in 1978, it proposes that at a certain critical density, orbiting debris shed by satellites and launch vehicles will begin to impact on and shatter other satellites, producing a cascade of more debris, so that the probability of any given satellite being hit rises, leading to a chain reaction that effectively renders access to low earth orbit unacceptably hazardous.
This isn’t just fantasy. There are an estimated 300,000 pieces of debris already in orbit; a satellite is destroyed every year by an impact event. Even a fleck of shed paint a tenth of a millimeter across carries as much kinetic energy as a rifle bullet when it’s traveling at orbital velocity
Source: The sky’s gone dark – Charlie’s Diary