4 ms·

Forgive my ignorance, but why is excess CO2 such a challenge? Isn't it extremely easy to simply vent it into space/the nearly-empty moon atmosphere?

jjk166 5y ago
Carbon isn't plentiful on the moon's surface so you want to conserve it for long duration missions/permanent habitats. Unfortunately storing it as CO2 in the air isn't great for human health.
- ajuc 5y ago
  You need food production anyway for a sustainable moon base. After the harvest store waste plant matter and burn it over the next season to keep the CO2 concentration in air good for plants and for you. It's a closed cycle if you eat/burn everything you grew each growing season, and you can keep the air CO2 concentration stable by adjusting how much waste matter you burn vs how much CO2 is captured by the plants. You need about 2000 m2 of corn to feed one person over 1 year and just 100 m2 of corn will capture the CO2 exhaled by that 1 person in 1 year. Assume we live in horizontal lava tubes 300m wide, let's say 10 meters of that tube per person to have some margin of error. That's <535 kg of CO2 in air in that section of the tube and ~8000 kg of CO2 captured in corn planted there the moment before harvest. It's doable IMHO. At least napkin math checks out.
  - loonster 5y ago
    Corn is a great plant optimized for production per acre. On the moon it may be more beneficial to optimize for carbon stability. Get plants with a more favorable Edible Carbon::Total Carbon ratio. A plant that can be harvested continuously would also be beneficial. The ideal plant may be something simple like grass. We can't eat it, so would need another intermediate step. Possibly Cows or Sheep. These would be grown for milk and not meat.
    - klondike_klive 5y ago
      So one day there really could be such a thing as moon cheese.

4 ms·

Forgive my ignorance, but why is excess CO2 such a challenge? Isn't it extremely easy to simply vent it into space/the nearly-empty moon atmosphere?

by coryfklein 5y ago

jjk166 5y ago
Carbon isn't plentiful on the moon's surface so you want to conserve it for long duration missions/permanent habitats. Unfortunately storing it as CO2 in the air isn't great for human health.
- ajuc 5y ago
  You need food production anyway for a sustainable moon base. After the harvest store waste plant matter and burn it over the next season to keep the CO2 concentration in air good for plants and for you. It's a closed cycle if you eat/burn everything you grew each growing season, and you can keep the air CO2 concentration stable by adjusting how much waste matter you burn vs how much CO2 is captured by the plants. You need about 2000 m2 of corn to feed one person over 1 year and just 100 m2 of corn will capture the CO2 exhaled by that 1 person in 1 year. Assume we live in horizontal lava tubes 300m wide, let's say 10 meters of that tube per person to have some margin of error. That's <535 kg of CO2 in air in that section of the tube and ~8000 kg of CO2 captured in corn planted there the moment before harvest. It's doable IMHO. At least napkin math checks out.
  - loonster 5y ago
    Corn is a great plant optimized for production per acre. On the moon it may be more beneficial to optimize for carbon stability. Get plants with a more favorable Edible Carbon::Total Carbon ratio. A plant that can be harvested continuously would also be beneficial. The ideal plant may be something simple like grass. We can't eat it, so would need another intermediate step. Possibly Cows or Sheep. These would be grown for milk and not meat.
    - klondike_klive 5y ago
      So one day there really could be such a thing as moon cheese.