Space Day Saturday
How much water can an astronaut on the ISS consume each day?
Before we go up into space, let’s start down here:
How much water do you consume in a day?
(And by consumption I mean everything: drinking, showering, bathing, flushing, cleaning,…)
Ok, I admit I’ve never measured my daily use before either, but experts say it’s up to 350 liters and day.
I guess it’s not difficult to imagine that water, given how widely it is and needs to be used to sustain a human organism, has to be rationed in a place that has no natural water source.
Each astronaut can use about 4.4 liters of water per day.
Most of that is used for drinking or injected into food pouches to rehydrate the content.
Only 0.5 liters are used for personal hygiene. To wash themselves, astronauts simply use wet towels as running water would only splash everywhere and might harm the equipment more than necessary, the same goes for water flushing (the excrements are sucked down).
Dirty clothes aren’t washed at all, by the way. They’re just loaded onto an unmanned resupply vessel which will burn up when reentering Earth’s atmosphere.
Water recycling aboard the International Space Station
To be as self-sufficient as possible, all forms of used liquid (like sweat, breath and urine) is being recycled to produce fresh drinking water which is actually purer than anything you could get out of a tap!
Currently, the recycling rate reaches about 93%. The remainder is replenished with water that gets flown up from Earth in special bags. There’s also a contingency water supply holding some 2,000 liters.
Now while a recycling rate of 93% sounds pretty great, at least 98% are needed to make the station (and any long-term expeditions) self-sufficient with regard to water.
Final thoughts
Maybe you’re not interested in space technology at all. But if you read this far, something must’ve piqued your interest!
If you don’t know why you clicked, consider this idea: Water is life, we all know it. We also know (even though we like to ignore it) how privileged many of us are to be able to just open the tap and get as much drinkable water as we please.
For all those people who don’t have that privilege (which is actually a basic need), a great recycling system might be a huge step closer to a life in dignity.
And if space technology can play a part in making life on Earth better, I’m in for it! What about you?