It is said that NASA used 100-percent-Oxygen artificial atmosphere in their spacecrafts prior to Apollo 1. I do not understand how NASA planned to maintain this atmosphere, as even the human flatulence is composed of:

  • Nitrogen: 20-90%
  • Hydrogen: 0-50% (flammable)
  • Carbon dioxide: 10-30%
  • Oxygen: 0-10%
  • Methane: 0-10% (flammable)

In a space settlement with an atmosphere consisting of only oxygen and nitrogen, how would the methane be dealt with?

  • 3
    $\begingroup$ After some days in a 100 % oxygen atmosphere human flatulence would contain no nitrogen. $\endgroup$
    – Uwe
    Feb 5, 2020 at 17:22
  • $\begingroup$ Then it is related to the air we breathe. Thank you. $\endgroup$
    – loceteg166
    Feb 5, 2020 at 17:36
  • $\begingroup$ Methane could be removed by passing the air over a hot catalyst. CH4+2O2=>CO2+2H2O. $\endgroup$ Feb 5, 2020 at 18:07
  • 3
    $\begingroup$ Re, "I do not understand how NASA planned to maintain this atmosphere..." They didn't plan to maintain it. The duration of those early space flights were measured in hours. Even the moon missions, were short enough that their only real concerns were replacing oxygen and removing CO2. $\endgroup$ Feb 5, 2020 at 18:15
  • 1
    $\begingroup$ During the flight outside the atmosphere the whole Apollo mission used a 100 % oxygen atmosphere inside the spacecraft as well as in the suits. $\endgroup$
    – Uwe
    Mar 26, 2020 at 22:38

1 Answer 1


Answer: in the Apollo program, methane was absorbed with activated charcoal filters. In a space settlement, these filters would be regenerated as needed.

During Apollo, Lithium hydroxide was used to remove CO2 by converting it to lithium carbonate, and activated charcoal adsorbed what are politely referred to as “odours”.https://airandspace.si.edu/collection-objects/lithium-hydroxide-canister-command-module-apollo-11/nasm_A19791592000

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Activated charcoal (also known as activated carbon) is usually made by processing carbon with heat and steam. This forms fractal miroporosities which will adsorb a wide range of chemicals.

Methane is highly bound by activated charcoal and has it been investigated as a medium for storing natural gas. The charcoal can be regenerated using heat and reverse gas flow in a “Pressure Swing Adsorbtion” technique.


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