NASA has big plans to send humans to Mars
by the 2030s.
And getting there isn't just a job for rocket scientists.
Chemists are confronting some of the big challenges
of getting a spacecraft to Mars, and keeping
its human passengers safe and healthy.
It was the subject of a two-day symposium
during the ACS national meeting in Washington,
D.C. last month.
That’s where we caught up with Janet Kavandi,
director of NASA’s Glenn Research Center,
to talk about the connection between chemistry
and Mars exploration.
Chemistry has a huge part to play
in almost every part of our lives, including
a journey to Mars.
We will need chemistry to help define how
we grow plants, how we create our own medicines
on the planet, how we will generate our own
breathing air.
There's all kinds of applications for chemistry
in space.
That starts with getting to the planet.
Sending stuff into space is expensive, and
astronauts on a multiyear mission are going
to need a lot of stuff.
NASA researchers are investigating whether
carbon nanotubes could be used to make lightweight
composite structures to reduce mass and therefore
the cost of escaping earth’s gravity.
If we want to go to Mars and not come
back, if we do a one-way-trip, it would be
about a hundred thousand dollars a pound.
If we want to come back, that scales to about
a million dollars a pound.
So every pound we save is extremely significant.
Tests of early composites using carbon nanotube
yarns show mechanical properties comparable
to unidirectional carbon fiber, the current
reigning champ of lightweight aerospace materials.
And Siochi’s team is working to further
improve the nanotube composites.
For carbon nanotubes, right now we're
basing the composite work that we're doing
on resins that were originally developed really
for carbon fiber.
But carbon fiber and carbon nanotubes are
not exactly the same, and so now we're stepping
back and trying to figure out how we can tailor...
we need to be thinking about how we tailor
the chemistry of resins specifically to interact
optimally with carbon nanotube surfaces.
With every pound at a premium, astronauts
can’t possibly bring everything they'll
need on their journey to Mars.
Up there if something breaks, you
can't go buy another one.
And you can't go to the grocery store if you
need food, and you can't go to the pharmacy
if you need medicine, so you’ll have to
learn how to make your own up there.
And we're trying to learn how to use printing
and in situ resource utilization to create
a lot of the materials that we need while
we're there on the planet.
Mark Blenner from Clemson University is one
of the people tackling this challenge of in
situ manufacturing on Mars.
His work involves engineering microorganisms
to produce polymers, nutrients, and other
useful products as they’re
needed.
So in situ manufacturing really means
making what you need in place, so if for example
we're talking about going to Mars, it's being
able to manufacture materials, nutrients,
food, using the resources available on Mars.
And what’s available is waste from astronauts,
notably their nitrogen-rich urine and the
carbon dioxide in their breath.
At the ACS meeting, Blenner outlined his vision
for a biochemical space factory involving
a yeast called Yarrowia lipolytica that can
take these feedstocks and convert them into
useful products, like polyesters.
Blenner anticipates then 3-D printing these
polymers to make tools or other parts that
astronauts may need.
Blenner’s team can also engineer the yeast
to manufacture nutrients, such as Omega-3
fatty acids, that could help keep astronauts
healthy during their trip to Mars.
Omega-3s in particular are useful
for astronauts because it's been implicated
in prevention of bone loss, which is a serious
problem that astronauts face.
Keeping astronauts safe and healthy during
their flight to Mars requires not only good
nutrition, but sensors to monitor their exposure
to certain chemicals, along with radiation.
Researchers like Tim Swager of the Massachusetts
Institute of Technology are focused on the
former, developing next-generation tools to
sense potential threats along with with the
current stalwart of analytical chemistry,
the mass spectrometer.
A problem with something like that,
though, is it can get fouled and it's complicated,
expensive, and if you suck something into
it that contaminates it you're really stuck.
Swager says he’s fusing chemistry and nanotechnology
to make miniaturized chemical detectors with
fewer vulnerabilities than more sophisticated
instruments.
His team is developing inexpensive sensors
based on carbon nanotubes that can operate
continuously on minimal resources.
One of our favorite platforms is carbon
nanotubes.
We can do different types of functionalization
with them.
That functionalization makes them interact
specifically with the chemicals of interest.
So we really need versatile sensors
that can detect many different things in a
changing environment and be a trigger to know
that something's going wrong.
While Swager predicts astronauts may still
pull out the mass spec for precise chemical
identification, he sees a benefit to having
a simpler alternative that can always be on
duty.
But as promising as this all sounds, the researchers
we spoke to stressed that putting humans on
another planet is complicated, and a mission
to Mars can’t afford to rely on unproven
technology.
NASA’s Office of Inspector General recently
released a report emphasizing the technical
hurdles of this mission.
2030 may feel like a long way off, but for
the scientists making the materials and technology
to get to Mars, it’s just around the corner.
Despite these challenges and deadlines, we
left the meeting with a sense of optimism
about this mission and those that follow
it.
So I would say we are working on
the materials now to have things ready for
the 2030 timeframe.
Those things are in process now, have been
for several years, and will continue to be
a process that we endure for a long time.
This is just a sampling of the space chemistry
we’ll be keeping an eye on.
What chemical space travel technology fascinates
you?
Let us know in the comments.
