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Hi, I'm Maria and this is NASA Now for January 25, 2012.
In order to survive in space, we all need air and water.
So how can the astronauts
on board the ISS maintain a constant supply 24/7,
365 days a year?
Our guest today will tell us about her unique role
in monitoring the life support and cooling system
on the International Space Station.
That's ahead, first here's what's happening at NASA Now.
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In December of last year,
crewmembers of Expedition 30/31 successfully docked
with the International Space Station.
The crewmembers are NASA astronaut Don Pettit,
Russian cosmonaut Oleg Kononenko
and European Space Agency astronaut Andre Kuipers.
The crew will be busy with dozens
of experiments during their time aboard the station.
They will be examining what kinds of materials are suitable
for the harsh environment of space.
How can we build those materials,
and what can microgravity teach us
about manufacturing processes here on Earth?
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When you're orbiting the Earth in the vacuum of space,
it's not that easy to find a steady supply
of oxygen and water.
That's why NASA has developed special systems
to manufacture them on board the ISS.
Today we are joined by Tess Caswell,
from Johnson Space Center.
Tess operates the life support systems aboard the International
Space Station.
Hi Tess, I've heard two different acronyms associated
with life support on the ISS - ETHOS and ECLSS,
could you tell us what they stand for and what they do?
Well ECLSS is one of the more traditional ISS flight
controller positions in mission control and it stands
for Environmental Control and Life Support System.
This was recently combined with the thermal system to make ETHOS
so we're now Environmental and Thermal Operating Systems.
The ECLSS officer is responsible for the life support system
on the Space Station, so all of the equipment that provides air,
provides water to the crew, keeps it a nice temperature
on board the Space Station as far as air temperature.
The thermal officer is responsible
for the water-cooling system
that actually maintains the temperature of things
like the equipment and computers onboard ISS rather
than just the crew.
Do you need to deliver oxygen to the Space Station?
It's very expensive to launch oxygen to the Space Station.
Every time you launch a vehicle into space,
it cost millions of dollars.
So if we can make it on the Space Station,
it's a lot cheaper and a lot easier.
There is a lot of chemistry involved
in producing oxygen on ISS.
We have to take water and break it apart into the atoms
that it's composed of.
We use the oxygen to put into the air
so the crew can breathe it
and the hydrogen can either be vented overboard
or we can send it to the Sabatier reactor,
which combines it with the CO2
that the astronauts have breathed
out to create more water, which can then go back into the loop.
So, the ETHOS operators run the oxygen generator to create
that oxygen so that the astronauts can breathe while
they are running science experiments
that improve life on Earth.
So what about water, how do you keep a steady supply?
All of the water on ISS can be recycled.
We have a system that can recycle condensation
into drinking water and we can also recycle urine
into drinking water.
That's amazing - just like our water purification systems here
on Earth, but much more efficient.
To change the subject, you mentioned that part
of your job is thermal control or temperature.
Why is that so important?
The thermal system is crucial to the ISS because it keeps all
of the computers, all of the hardware
on board the Space Station at a nice cool temperature
so they don't overheat and break.
It does seem sort of counterintuitive
that we would need a system to get rid of heat
when space is really, really cold, but the ISS is kind
of like an insulated tin can with a bunch
of computers running inside it.
Even if it's cold on the outside,
all those things producing heat
on the inside make it really warm inside the can.
So we need a system that takes that heat and moves it outside
of the Space Station so that it can go to space
where it's really cold.
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As our expert shared, water is critical
to sustaining life in space.
Here's a design challenge
where you can create your own water filtration system.
Teachers, your students can immerse themselves
in a real world science experiment.
Check out Engineering Design Challenge: Water Filtration,
which can be found on the NASA Explorer Schools'
Virtual Campus.
Well that's it for NASA Now, look for us on Facebook,
and leave a comment about today's show.
We'll see you next time on NASA Now.
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NASA Now comes to you from the Virtual Campus
at NASA Explorer Schools.