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The water cycle presented by David Saint-Jacques


Uploaded on June 7, 2019


The water cycle presented by David Saint-Jacques

2019-06-07 - CSA astronaut David Saint-Jacques talks about the importance of the water cycle on Earth and explains how this system is replicated on the International Space Station. (Credits: Canadian Space Agency, NASA)


David Saint-Jacques: Water is essential to life. Humans, animals, plants, insects, fish– all living beings need water.

Water is constantly and naturally recycled through what we call the water cycle.

Water in the lakes and oceans evaporates to form clouds, and when the clouds are full, the water falls back to earth as rain, which flows in the rivers and refills the lakes and oceans.

There is never any new water on Earth. It’s always the same old water, recycled and cleaned all over again.

If you think about it, the water we drink on Earth today has a little bit of dinosaur pee in it from millions of years ago.

Here inside the International Space Station, we imitate this natural process with a machine. It’s a complex and autonomous system that recycles water for us.

It collects our urine, our sweat, the water vapour from our breath, and the water we use to wash ourselves.

The system is very effective and is critical to long-duration space missions.

We continue to develop water collection and filtration systems so we can become more and more self-sustaining.

If we want to colonize the Moon or Mars one day, this technology will be absolutely essential.

Obviously, the idea of drinking water from our colleagues’ sweat is not the most appealing.

Here, they might even say that today’s pee is tomorrow’s coffee.

But after all, water is water, even if it’s recycled! Bye-bye.


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