Scientists have a plan to make breathable oxygen on
Mars for the first time
When it comes to deep-space travel and exploration, oxygen
is one of the most important elements in the mix. Humans breathe it to live and
rockets burn it to fly.
That's why a team of scientists at MIT is working on a
machine that could make oxygen on Mars. This kind of a set up could play a
major part in future manned missions to Mars.
The atmosphere on Mars consists of 96% carbon dioxide and
less than 0.2% oxygen (Earth has about 21% oxygen). If astronauts tried
breathing the air on Mars, they would quickly suffocate.
But hauling tanks of breathable oxygen to Mars takes up
precious space that could otherwise store food and scientific instruments.
That's where the Mars Oxygen In situ resource utilization Experiment (MOXIE for
short) comes in.
Last August, NASA
announced that MOXIE, along with six other scientific instruments, would
get a seat on the Mars rover 2020 mission — NASA's rover mission to follow up
on Curiosity's work. Moreover, the Mars 2020 rover will generate electric power
the same way as Curiosity, which would power all six instruments on board,
including MOXIE.
The mission is projected to cost between $1 and
$2 billion and, if fully funded, would launch between July and September
of 2020 and land between 150 to 300 days later.
Former NASA astronaut Jeffrey A. Hoffman is a principle
investigator for MOXIE and talked to Business Insider at BBC FUTURE's
World-Changing Ideas Summit about the project.
"It will be the first time when we will actually
produce oxygen on the surface of Mars," he said.
Making oxygen on Mars instead of bringing it along for the
deep-space roadtrip would drastically reduce the cost of future manned missions
to Mars.
Space’s Falcon 9 lifts off early on September 21, 2014, from
launch complex 40 at Cape Canaveral. BRUCE WEAVER/AFP/Getty Images By
estimating how much it would cost to send enough rocket propellant into space
that could fuel a rocket on Mars, Hoffman estimates that an oxygen-producing
machine 100 times the size of MOXIE could save future Mars missions billions of
dollars.
"The amount of oxygen we will need for the rocket is
several tens of tons. Let's assume 30 tons," Hoffman told Business Insider
in an email. "To get 30 tons of oxygen on the surface of Mars, you need to
launch 300 to 450 tons of propellant from the surface of the Earth into Earth
orbit."
Since it costs about $10 million to launch one ton of
anything into space, this would save a manned mission between $3 and $4.5
billion.
"Now it is probably that launch costs will come down
somewhat through efforts of SpaceX and other launch companies, but the cost of
launching all this oxygen is still huge, which is why producing it on the
surface of Mars can make an expedition more affordable."
While on Mars
The way MOXIE works is relatively straightforward: It will
take the abundant carbon dioxide in the Martian atmosphere, which is made of
one carbon atom and two oxygen atoms, and isolate one of the oxygen atoms. They
will then combine the oxygen atoms together to make O2, which is what we
breathe here on Earth.
After creating oxygen and carbon monoxide, MOXIE will
release those two gases back into the Martian atmosphere.
REUTERS "We're not storing the oxygen for any length of
time," Hoffman told Business Insider in a later interview. MOXIE will only
hold on to the oxygen for long enough to measure its purity and then release it
back into the atmosphere.
With MOXIE, scientists are shooting for 99.6% pure oxygen —
the same purity they would shoot for with a larger version of MOXIE.
It's important to measure the purity
of oxygen because "you better be sure that the gas mixture does not
contain much carbon monoxide or carbon dioxide," Hoffman said when
referring to oxygen that future astronauts would use to breathe.
Although the carbon monoxide and
oxygen that MOXIE makes will re-enter the atmosphere, this will not hinder the
planet's potential biosphere or alter its atmosphere, Hecht explained to
Business insider.
"If you release the carbon
monoxide into the Mars atmosphere, eventually it will combine with a very small
amount of residual oxygen that's there and turn back into carbon dioxide,"
Hecht said.
Right now, MOXIE is designed so that
it will operate for 50 Martian days (about 51 Earth days) and will produce
about 20 grams (0.7 ounces) of oxygen per hour. Hoffman and Hecht hope to
send a larger version of MOXIE to Mars some time in the 2030s that would
produce about 2 kilograms of oxygen per hour.
Ultimately, the idea is that NASA
would send both an empty rocket and a larger version of MOXIE to Mars, before a
planned human mission. The oxygen-producing machine would take about a year and
a half to fill the rocket with enough liquid oxygen for lift off. Then, when
astronauts arrived, they would have a rocket fueled up and ready for launch to
take them home, Hoffman explained.
How it works
NASA/JPL/Marco Di Lorenzo/Ken
Kremer-kenkremer.com The way MOXIE does this is to basically run like a fuel
cell in reverse. To work, fuel cells convert a type of fuel, such as gasoline,
into electricity through a chemical reaction that often requires the presence
of oxygen.
However, since oxygen is so rare on
Mars, MOXIE will instead start with electricity, produced by a separate
machine, and use it to extract carbon dioxide in the air to produce breathable
oxygen.
Over the next year, Hecht, Hoffman,
and the MOXIE team will be testing prototypes of MOXIE here on Earth before
finally building the real thing in preparation for the upcoming Mars 2020
mission.
As of right now, NASA has no
official approval for Mars missions after Mars 2020, which means a larger
version of MOXIE is more an idea than a reality at this point. But it's one
step in the right direction.
