system
Given the following post, respond as if you're commenting on Reddit:
human
What happens to the exhaust gases of a spaceship once in orbit?

Take for example the Soyuz.
Once in out of the atmosphere and in a stable orbit, it has to reach the ISS. It does that by firing its engines at the appropiate time. Same thing  for deorbiting.
Since it was already in orbit, where do the exhaust gases go? Do they stay in orbit, fall to the Atmosphere or float away in vacuum?
gpt
Force = Mass x Acceleration.

A chemical rocket reaction will impart the same force on the spacecraft as with the exhaust gases, although the latter will have a much lower mass. Therefore, the gas particles will accelerate far faster than the rocket, meaning that they will likely either reach escape velocity or re-enter the atmosphere, depending on the direction of thrust (i.e., if you're burning to rendezvous with the ISS, then the particles will end up slower than your orbital velocity, meaning that they fall back to Earth)

Clearly, both in terms of quantity and dispersal, the actual effect of the exhaust in the atmosphere is negligible.