system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: With the amount of space debris orbitting the planet, how do satellites and space stations mitigate against impacts?
gpt
"Space debris" is a continuum. The frequency of a piece of debris is directly related to the size of that debris - small particles are significantly more likely than huge chunks of matter. Satellites and space stations are just built with enough external shielding to survive the constant onslaught of tiny particles (mm scale and below).

Larger objects than that are **actively tracked**, and if something is on a collision course with a space station we have enough of an advance warning to move the station out of the way using its onboard thrusters. These happen every so often, maybe once every few years.

Also, there's not actually as much space debris as you might think. Space is a big, big place. Even down in low-earth orbit, the chance of getting pummeled by space debris is only really a concern for very long-lived projects like the ISS that survive in orbit for many years. And this is the "high risk zone". Out in the far reaches of geostationary orbit (many times the altitude), space debris is a non-issue. This is where most satellites live, especially communications satellites.