system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do astronauts prevent the buildup of carbon dioxide inside the spacecraft?
gpt
There are CO2 scrubbers that remove it. This is typically either lithium hydroxide or a zeolite that will chemically bind to the CO2 and pull it out of the air. By circulating the air of the craft through this system the CO2 concentration can be kept low and the astronauts able to breath.