What is the most indispensable thing for human beings? Maybe it's water, oxygen, and sunlight. If people do not have oxygen, then the body can not carry out normal breathing, people will suffocate and die.
The creatures on Earth are just so fortunate to live on a planet with various living conditions, with suitable air composition, abundant water resources, and appropriate light. However, when people enter the space station, it is 400 kilometers away from the ground of our earth, and the atmosphere is quite thin. So the question arises, when astronauts live on the space station, where does the oxygen they need come from? Was it all sent from Earth? Or is there any good way for the space station to make oxygen?
<h1 class="pgc-h-arrow-right" data-track="3" > the International Space Station</h1>
We can first look at the solution to the International Space Station, which was built in 1993 with the participation of 16 countries. It has been open for more than 20 years, so how exactly is the oxygen and water supply on the International Space Station?
The orbital altitude of the International Space Station is about 350-400 kilometers, and as everyone knows, the oxygen here is very thin, let alone any water source. So these necessary elements of life will not all be directly compressed and sent up, right?
Oxygen is indeed compressible, but at the same time the risk of compressing oxygen is very large, in the 60s of the last century, the United States conducted lunar probe tests, because the cabin wires generated sparks, combined with oxygen had a violent reaction, directly resulting in the three astronauts in the cabin at that time all killed.
Therefore, there is still a strong safety hazard to transport oxygen directly to space, after all, in the pure oxygen environment, once there is a similar "spark", then the lives of all astronauts will be threatened.
Since oxygen is not sent up, it can only be made on the space station, so how do people achieve it?
<h1 class="pgc-h-arrow-right" data-track="9" > electrolyzed water</h1>
The easiest way to make oxygen is to electrolyze water. As we all know, electrolyzing water will break down water into oxygen and hydrogen. Although this method is very simple, we will not choose to use this method on the surface of the earth, after all, it is too expensive to use electricity . But in space, it can use solar panels to generate electricity, and then directly electrolyze the water, which can be said to be a step in place.
But electrolyzed water not only produces oxygen, but also hydrogen, hydrogen is still a flammable gas, so how to deal with hydrogen?
According to the principle of human respiration, when people inhale oxygen, carbon dioxide will be released, and these carbon dioxide and hydrogen will be combined to generate methane and water, so astronauts only need to discharge methane out of the space capsule and continue to use water.
So how much water does it take to electrolyze it?
Under the conditions of the space station, the electrolysis of a liter of water can decompose 620 liters of oxygen, and the oxygen demand of an astronaut in a day is 550 liters, that is to say, the electrolysis of one liter of water a day is enough to maintain the life activity of an astronaut on the space station for a day.
<h1 class="pgc-h-arrow-right" Data-track="15" Where does the water from > the space station come from? </h1>
The problem of oxygen is solved, oxygen is electrolyzed water, so is there such a large amount of water stored in the space station?
Water is also indispensable in life, the water of the space station will be sent up through the cargo spacecraft, these water are packed in a "bag", a water bag has 20 liters of water, of course, these water is not directly used to electrolyze water. It is still too luxurious to do so in such a dramatic situation as the water source.
There are too many places that need to use water in life, and the cost of sending water to the sky is also quite high, so the space station is an efficient circulation system, every drop of water in the entire space station will be reasonably stored and used, even including astronauts' urine, sweat, etc., will be treated by professional wastewater into pure water, and then through electrolysis, to obtain oxygen.
Of course, in the environment of space, astronauts are not pure oxygen inhaled, but a mixture of nitrogen and oxygen, close to the composition of Earth's air, safer.
I can't help but sigh that the space station is probably the most efficient place in the world for energy use.
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