Starting with a verse from the Quran: “Do the disbelievers not realize that the heavens and earth were ˹once˺ one mass then We split them apart? And We created from water every living thing. Will they not then believe?” (Surah Al-Anbiya – 30). Without water, life on earth would cease to exist, making it the most crucial compound for creating sustainable life. And as you are aware, water plays a vital role in all biological processes within all living organisms, e.g., up to 75% of the human body is water.
In our modern era, we witness an abundance of water and ease of access to it, and that is due to the advancement throughout the years that have improved water quality and facilitated its transportation across the globe. However, what about astronauts swimming in space, aboard the International Space Station (ISS)?
The ISS orbits at an altitude of approximately 400 kilometers above Earth’s surface, making transporting water to the station a significant challenge due to water naturally being relatively dense. Thus, the process of transporting water to the space station is costly, with the cost of delivering one gallon to the station exceeding $83,000. This makes it impractical and non-feasible, especially because astronauts consume around 3 gallons of water a day. The challenge inspired scientists to find alternatives to create a sustainable environment on the ISS, until 2006, where NASA developed a system that recycles and purify water used in the station, known as the Environmental Control and Life Support System (ECLSS).
Credit: NASA – Water Bubble in Space
Credit: NASA– Mockup of the ECLSS, 2001
In 2008, the water recycling and purification system was activated to create a sustainable environment aboard the station, producing clean and usable air and water. This machine uses chemicals to simulate the water cycle in nature through three main stages. The first stage involves collection of sewage water and filtering out any impurities; the second stage involves further filtering of water to remove all organic and inorganic impurities. And finally, the water undergoes catalytic oxidation to eliminate bacteria and viruses. This process produces water of high purity and is used by astronauts for drinking and bathing; in fact, the water produced is so high in purity that it sometimes surpasses the quality of water on earth.
Although the presence of the water recycling and purification system reduces the need for water transportation to the space station because there is minimal loss of water in each cycle. As the current efficiency of the recycling and purification system is estimated at 90%, necessitating periodic water replenishment. More importantly, however, astronauts must be economical in their water consumption, which involves changing their water usage habits. For example, they do not use faucets to wash their hands and take showers as on Earth, instead opting for wet wipes, reducing their water consumption from 50 liters to less than 4 liters.
In addition to purifying water, the machine on the space station also plays a crucial role in purifying the air and providing oxygen through an electrolysis process. This process is powered by solar panels, splitting water into oxygen and hydrogen, where the released oxygen is used to sustain the station’s interior atmosphere, while the hydrogen is combined with carbon dioxide to produce water and methane. Moreover, the air purification system efficiently eliminates harmful gases like ammonia, acetone, and other gases generated during scientific experiments ensuring a safe and breathable environment for astronauts aboard the space station.
Credit: ESA – How Water is Recycled on the ISS
The exploration of space and the establishment of the International Space Station (ISS) have presented numerous challenges that have significantly contributed to scientific advancement and resulted in various inventions. These developments have not only enhanced the quality of life on the station but have also led to a reduction in the operational cost. However, the ambitions of scientists do not end there, they are continuously striving for further improvement as their ultimate goal is to create a sustainable environment for the ISS, where water and air used on the station can be recycled with 100% efficiency.
It is important to note that these remarkable efforts in the space sector do not only benefit the astronauts abord the ISS, but also have far-reaching positive implications for life here on earth. The advanced technological solutions developed for space exploration are being utilized without the general public’s awareness that these innovations were invented for the use of space. Therefore, the impact of these advancements extends beyond space exploration and holds promise for addressing environmental challenges and promoting sustainability on our home planet.
Written By: NSSA Aerospace Engineer – Ali Al-Mahmood