How Do Oxygen and Water Never Run Out on the ISS?

The International Space Station is a man-made satellite orbiting our planet at an altitude of about 400 kilometers and orbiting at 7.8 kilometers per second.

The station is home to astronauts who conduct research and conduct a series of experiments to improve our knowledge of how things work in space.

Astronauts, like us, have essential basic needs.

We can say that there are many life support systems on the International Space Station to ensure that the crew lives in space as comfortably as possible.

There is no doubt that the three most important things astronauts need to survive miles above the Earth’s surface are water, food and oxygen.

Although the station actually remains inside the Earth’s atmosphere, at this altitude, known as the thermosphere, air molecules are too sparse to be used for breathing. So in this case, how do they not run out of oxygen?

They produce the oxygen they need at the station.

NASA is really good at recycling what they already have on the station. The system responsible for producing the oxygen needed on the International Space Station is called the Oxygen Generation System.

This system separates water into its components by electrolysis, releasing oxygen and hydrogen gases.

We can briefly explain the electrolysis process as follows;

The process of separating chemical compounds dissolved in a liquid with the help of electric current is called electrolysis. When we apply this process only for water, water (H2O) splits into oxygen (O2) and hydrogen (H2) molecules.

Oxygen gas obtained by electrolysis mixes with the air of the space station. Thus, the breathable air of the station can be maintained. The hydrogen released during electrolysis was removed from the station because it was an explosive gas. Until 2010 that is. We’ll get back to that in a moment, but let’s look at the water part first…

They produce oxygen from water, so how does the water not run out?

Nothing goes to waste on the International Space Station, which is tasked with providing enough power, breathable air, clean water, and the right temperature and humidity 24 hours a day, 7 days a week.

The water recovery system on the space station supplies most of the clean water needed. Capable of capturing and condensing moisture in the air, this system purifies all kinds of wastewater, including the sweat and urine of research animals and astronauts at the station, and makes it ready for reuse.

As strange as it may sound, NASA says the water obtained from the purification process is even cleaner than bottled drinking water on Earth.

They also use hydrogen to produce water.

Another system used on the International Space Station since 2010 captures the carbon dioxide produced by all kinds of living activities in the station from the air and separates it into carbon and oxygen molecules.

When the hydrogen remaining from the production of oxygen by electrolysis enters this system, water and methane are formed after some chemical reactions. The resulting water can be reused at the station.

Since the amount of hydrogen used during this process is too much, the hydrogen produced by electrolysis is sometimes not enough. In these cases, since it will be very costly to send enough water from Earth to the space station, oxygen and hydrogen gases can be sent in compressed tubes according to the need.