This episode is sponsored by Wren, a website with a monthly subscription
that helps fund projects to combat the climate crisis.
Click the link in the description to learn more about how you can make
a monthly contribution to support projects like rainforest protection programs.
[♪ INTRO]
It took years of work and billions of dollars for NASA
to put the first astronauts on the Moon more than fifty years ago.
After all that effort and expense, they couldn’t stay long.
Neil and Buzz spent just a couple of hours on the lunar surface.
Later missions extended the stay on the Moon to a couple of days.
But, now, with new technology and priorities, the next generation of astronauts
are expecting to spend a heck of a lot longer on their visits.
To do so, they’re going to need food to eat, water to drink, and air to breathe.
That’s a lot of material to ferry from Earth, so scientists and engineers are exploring
what resources they can leverage to help astronauts live off the lunar land itself.
One of the most promising ideas is that, in the midst of the vacuum of space,
the next era of Moonwalkers could breathe the Moon itself.
Well, after a little processing, that is.
The astronauts who land as part of NASA’s upcoming Project Artemis
will spend at least a week, and perhaps more than a month,
living at base camp and exploring the lunar surface.
China and Russia are thinking even bigger.
They imagine a lunar outpost that, like the International Space Station,
is permanently inhabited by the mid-2030s.
Making these lunar settlements a reality will require launching
all the materials and equipment needed to build and supply them from Earth.
To reduce the burden as much as possible, scientists and engineers are exploring
in-situ resource utilization, the idea of “living off the land” as much as possible.
It’s a new term for an ancient idea: bringing only enough supplies
to get where you’re going, and then produce more once you arrive.
Of course, the whole idea becomes a lot trickier when you start exploring space.
The lunar soil, which scientists call lunar regolith,
is a lot less inviting than farmland on Earth.
But it does contain a key ingredient for life: oxygen.
In fact, lunar regolith is, on average, more than 40% oxygen.
That’s a big deal, since it is rather inconvenient to stop breathing while exploring.
All that oxygen is locked up in the form of minerals, including silicon dioxide,
aluminum oxide, calcium oxide, magnesium oxide, and titanium dioxide.
Altogether, those five minerals make up ninety percent of typical lunar regolith,
so if you grab a fistful of Moondust, you’re gonna come up with a fistful of oxygen.
Excavate just a cubic meter of lunar surface,
and you’ve got more than half a ton of oxygen.
Of course, you can’t breathe straight-up titanium dioxide,
so the real challenge is separating the oxygen atoms from everything else.
To solve that problem, chemists have been experimenting with rock mixtures
tuned to exactly match samples brought back by the Apollo astronauts.
In one promising study, published in 2019, researchers
were able to extract the oxygen using a surprisingly simple process: electrolysis.
It uses electricity to do a chemical reaction,
like separating the oxygen from the regolith.
But Moon rocks aren’t very conductive, so the key was to add a material called
an electrolyte to help the electricity flow.
In this experiment, they used calcium chloride.
Then, the mixture is heated to 950 degrees Celsius,
which is hot enough to melt the calcium chloride,
but not so hot that it melts the regolith.
Once things were at the perfect temperature, the researchers applied an
electric current that started the process of breaking the oxygen atoms free.
After 15 hours, 75% of the total oxygen had been extracted,
about a third of which was in a gaseous form suitable for breathing.
Would that be enough?
It just might.
For all our breathing throughout the day, we actually consume
a surprisingly small amount of oxygen.
NASA astronauts on board the International Space Station
consume an average of just 840 grams of oxygen per day.
So, if electrolysis could free the oxygen from the lunar regolith,
they wouldn’t need a lot of material per day to support a couple of astronauts.
And that’s assuming that none of the carbon dioxide
the astronaut breathes out is converted back to oxygen.
What’s more, the “leftovers” from the electrolysis process wouldn’t just be wasted.
The metal alloys left behind could be used as
a construction material or as part of another chemical reaction.
Oxygen extraction seems so promising that both NASA and
the European Space Agency, or ESA,
are planning missions to the Moon to test it out.
In October 2021, NASA signed an agreement with the
Australian Space Agency to develop a lunar rover for launch as early as 2026.
ESA’s lander, named PROSPECT, will pursue another promising idea:
extracting oxygen from water trapped in ice near the Moon’s south pole.
It could launch as early as 2025.
These techniques, or ones like them, will be key for any permanent habitation
on other worlds, whether that’s the Moon or even Mars.
When you’re going on a trip, you can bring everything you need with you.
But when you’re going to stay, you’ve got to learn to live off what’s around you.
And while scientists work to explore the Moon and a future home,
we can do our best to protect the one we have, Earth,
and today’s sponsor, WREN, can help with that.
They’re a website with a monthly subscription
that helps to fund projects to combat the climate crisis.
Wren searches around the globe for promising projects,
getting data on the ground to track their impact over time.
Like community tree planting in East Africa to sequester carbon
and improve the quality of the soil.
Over the long term we need governments to fund these projects,
but we can start by crowdfunding them now.
And as a bonus, we’ve partnered with Wren to protect
an extra ten acres of rainforest for the first 100 people
who sign up using our link in the description!
And as always, thank you for supporting SciShow Space.
[♪ OUTRO]