So imagine you’re an astronaut on International Space Station, looking out the window, and
you’re craving a pizza.
Pepperoni.
Cheesy.
Umm.
Let’s say it’s possible to order delivery.
What would that bill look like?
I’ll just put it this way: sending 1 lb of cargo into space costs about $10,000!
Not including tip!
So, how do space agencies afford to send supplies like oxygen, water, and food to their astronauts?
– Do they send it with the crew?
Before they found a more efficient solution, they’d pack all the water into space with
them in their rockets.
The water took up a lot of room that could’ve otherwise been used for other supplies.
That, and the added weight wasted fuel.
So short answer: nope, it doesn’t go with the crew from the get-go.
– That means they deliver it, right?
Eh, that’d be too risky…and expensive!
There’s no 100% guarantee that something bad won’t happen to the cargo ship at launch
or on the way to the International Space Station.
(Like, space pirates?)
If the cargo doesn’t get to the station, then the next delivery will have to wait a
very long time.
That’s not an option since it’s dangerous for the astronauts.
Ok, so let’s break it down item by item.
First, where do astronauts get their…
– Water The primary source of water for the crew is…
the astronauts themselves!
Whether it’s drops of sweat, condensation from breathing, or going to the toilet, all
this water gets processed through complex filtering systems.
When it comes out, it’s clean drinkable water.
Yes, you heard that right: astronauts recycle…their own body’s H2O!
In fact, 85% of their “tinkle” can be turned into clean water!
(off mic) We can say “tinkle”, right?
[ding] Okay. (back on mic) Sorry just checking with Mr. Strudelmeyer, the sensor.
We’re cool.
Water in separate cargo deliveries is still sent to the ISS.
But with the invention of the onboard Water Treatment System (WRS), everything has become
much simpler.
And with the help of a process called electrolysis, they’ve learned how to extract the necessary
reserves of oxygen from the water itself!
But more on that here in a bit.
For now, let’s see…
– How the WRS works The astronaut goes to the toilet and flushes
it all down.
The [sensor’s honk], pardon me……the liquid contents fall into a compartment that
rotates very quickly and works like a centrifuge.
This centrifuge is then heated.
Under cpressure and high temperature, the liquid evaporates and collects condensation
in an external chamber.
From there, the condensed water enters a tank.
All other moisture from the ISS – sweat and exhaled air – goes to this same tank.
From there, the water enters a separator where the liquid is cleaned of odors.
After going through several levels of filtration, it gets heated once again and disinfected.
And, presto – clean water is ready!
After knowing that, do you think you could live on the ISS?
Let me know down in the comments!
Ok, moving on to…
– Oxygen Ah, the question of the day!
Like I briefly mentioned, they can get oxygen from that same water.
Remember your chemistry classes in school?
Oxygen is the “O” part of H2O.
Here’s how they do it: an electric current is passed through water molecules to break
them down.
This process is called "electrolysis."
So after that, you’ve got 2 hydrogen atoms and 1 pure oxygen atom.
They collect those now separated oxygen molecules in special cylinders, and astronauts can breathe
easy!
But where do the remaining hydrogen molecules go?
They’re also used to the maximum benefit of the entire crew.
Through something called the Sabatier reaction, they mix the hydrogen with carbon dioxide
(the stuff you’re breathing out right now!) to create… water!
Incredible, right?
So, the ISS is completely independent of the Earth as far as its water and air reserves
go?
Unfortunately not.
Thanks to this complex system, it’s possible to produce a little over 4 lb of oxygen per
day.
That’s only enough for 2 people.
The ISS crew usually consists of 6.
To make up the difference, oxygen is delivered from Earth.
So, what about…
– Food Here, the ISS is entirely dependent on supplies
delivered from Earth.
All those freeze-dried packets of astronaut food go along with the crew when they head
to the station, or separate cargo is sent.
But you’d be surprised by the number of options they have.
According to NASA, astronauts dine on fruits, nuts, chicken, beef, seafood, candy, and even
brownies!
They also have coffee, tea, juices, and lemonade.
But why can’t they plant an indoor garden on the station to eat fresh fruits and veggies?
Well, it’s not as easy as it sounds.
How can plants grow in the vastly different conditions of outer space?
There’s no gravity, day and night are all over the place (the ISS sees 16 sunrises and
sunsets each day!), the air is dry, it’s cold.
Plus, the ISS might be as long as a football field, but it’s not like they have a lot
of room for a sprawling garden.
Well, the good news is, they’ve already figured out a solution to all this, and astronauts
are growing food up there!
In 2015, members of the 44th ISS crew ate lettuce that was fully grown on board!
The seeds had been sent from Earth.
Once in the station, they were put in a Veggie box with red, blue, and green lamps that each
provided a certain growing condition for the seeds.
The experiment was successful, and the astronauts even said that the lettuce tasted exactly
the same as it does on Earth!
Their next crop idea?
Tomatoes and cucumbers to go with that space salad!
– What do they do with their trash?
Just like you and me, astronauts have garbage too.
Disposable utensils, used towels, raw materials, empty food packets – you name it!
You’d think they could just chuck it out into the endless void of space, but that would
be littering!
Whenever they get a delivery, the cargo ship is docked to the station.
The astronauts get what they need from it, and then they load this ship with their trash.
After a few weeks, the supply vehicle is disconnected from the station, and it heads back to Earth.
It might make it to the surface or burn up in the atmosphere.
In short, astronauts don't litter!
– Then where does space debris come from?
Right now, there are tons of satellites floating around Earth.
You have them to thank for your GPS or satellite TV.
But there are so many of these things up there, that they sometimes crash into each other.
Their remains create space trash.
In addition to them, the uncoupled parts of launch vehicles become garbage too.
This garbage, seemingly harmlessly soaring in outer space, is a serious threat to the
ISS.
Even a dime-sized fragment of a satellite can penetrate the station's casing and lead
to major problems.
In all of the ISS’s 21 years, the station carried out 25 maneuvers to evade space debris.
Plus, the station is covered with protective plates that guard against a tiny piece of
debris shredding through it!
– From the ISS to Mars!
The cool thing about the International Space Station becoming more and more self-sufficient
is that it’s almost like a trial for larger missions in the future.
I’m talking about colonizing the Red Planet, baby!
Instead of being a “mere” 250 miles from Earth, we’d be 140 million miles from home!
That means deliveries (and trash dumps!) won’t be an option!
So, what will they do with their garbage?
Two words:
– Waste recycling The plan is to process all garbage using the
"liquid combustion" system.
Simply put, organic and inorganic waste would be collected, crushed, and mixed with hydrogen
peroxide.
After a day, an electric current is passed through this mass, and the oxidation reaction
starts.
All the garbage will be stored in a device, where they’ll put a colony of microorganisms.
They eat the trash and emit free electrons as a byproduct.
Electrodes and a battery will be connected to the device, which will accumulate energy.
You know what all that means?
Scientists have learned how to recycle garbage and turn it into electricity with the help
of germs!
That battery can hold a charge of 400 hours, after which the bacteria will need to be replaced.
If this all just sounds hypothetical, they’ve already pulled it off here on Earth in terrestrial
conditions.
The next step is to try it out in space!
Besides creating electricity with the help of bacteria, recycling waste will also be
good for gardening since it’ll contain nutrients and minerals for the plants!
(off mic) Oh, hey thanks Mr. Studelmeyer! [ding] Sure glad I didn’t say P[honk].
Oh well…
(on mic) Hey, if you learned something new today, then give the video a like and share
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