Today I saw a question: what gas do astronauts breathe in a spaceship? Is it ordinary air? Xiaobian curiosity consult some information, for your reference.

Ordinary air is composed of 20.93% oxygen, 78.03% nitrogen, 0.98% rare gas, 0.03% carbon dioxide and 0.03% others. The obvious oxygen and nitrogen have accounted for 98.96% of the total. Therefore, the gases in the spacecraft cabin are mainly composed of oxygen and nitrogen.

The air that the astronauts breathe is supplied by the titanium alloy "oxygen cylinder" and "nitrogen cylinder" carried by the spacecraft itself. The pressure regulation system installed in the cabin constantly makes up for the oxygen and nitrogen in the cabin to ensure a constant pressure of one atmosphere. The air in the cabin is necessary to be fresh, which is the first element. The ventilation and purification equipment in the cabin continuously filter and purify the exhaust gas such as carbon dioxide exhaled by astronauts.

On the ground, the cabin has been filled with good gas, titanium alloy gas cylinder is high pressure gas, after heaven, by the pressure adjustment device for gas transmission. Clean up the carbon dioxide and import fresh gas to maintain atmospheric pressure and air freshness.

Before China's shenzhou 5 spacecraft to return to the ground, open the door of the moment, a strong smell out of the first ingredient is carbon monoxide, which is fatal to the astronauts. This kind of harmful gas comes from two places primarily, it is the burning gas that the igniter leaks out during working hours inside the cabin, 2 it is from the non-metallic data inside the cabin excretion harmful gas. Later our country carried on the improvement, realized not only to ensure the cabin seal, but also to eliminate the harmful gas one-way drainage technology.