The airlock canisters release white fog; their supposed argon supply is said to draw fresh gas from deep underground.
After an outer-door breach, the canisters fire and fill the airlock with white fog. The supposed argon supply uses a pump and filter said to draw fresh gas from deep underground.
The canisters discharge a white fog.
They supply gas to the airlock, although the description of that gas as argon remains uncertain.
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