strength that could be
advantageous for 3D
printing applications.
However, modular
strong would Martian
concrete be? Mars has
a lot of sulphur in its
soil, and molten sulphur
is used to bind
some concrete
on Earth
underground living will
likely be the surest way to
protect Mars’ settlers from
cosmic radiation and intense
cold. Such digging could also
expose water, ice and other resources
under the surface for ISRU.
ADAPTING THE PLANET
NASA’s plans to send a manned threeyear
mission to Mars in the 2030s can
only happen if the astronauts have a
continual food supply.
A 2016 scientific and technical
information paper by NASA, “Frontier
In-Situ Resource Utilization for
Enabling Sustained Human Presence
on Mars”, suggests that protected
atmospheric environments that
harness either sunlight or artificial
light sources could be the answer to
our food storage needs. Robots will
also likely be employed — which is
no stretch given that robot agriculture
is firmly established here on Earth.
One thing is for sure: astronauts will
have to grow their own food. But how?
Typical science fiction concepts
would include modifying or
terraforming the planet’s atmosphere.
Humanity won’t have to go this far
thanks to aerogel, a synthetic porous
ultralight material. Specifically, silica
aerogel, which is a good insulator and
a poor conductor of heat.
The idea is that, if silica
aerogel shields were placed
over sufficiently icy regions
of Mars’ surface, then
photosynthetic life could
survive there with minimal
subsequent interference.
Mars’ colonists would
then have the capability
to grow their own food with
mushrooms, cyanobacteria and
even insects.
MATERIALS TESTING
Alongside the efforts of NASA
and SpaceX, tests of Earth-based
simulants of Mars’ elements will
determine whether humanity has a
viable future on Mars. JSC Mars-1a,
for instance, is made from basalt
sourced from a volcano in Hawaii.
There are a variety of Mars simulants,
they’re all based on basalt and are
selected for tests based on their
mineralogical properties, particle
sizes and distribution, among other
qualities.
For now, continued testing here
on Earth will assess the viability of
these materials and technologies
and lead to better replicas. Ongoing
tests include those by the University
of California in San Diego, US. Its
research examines the relatively
high concentrations of perchlorate
compounds, containing chlorine, in
Martian soil that render it toxic.
The studies aim to assess
whether the perchlorates change the
behaviour of the tested materials,
focussing on impurities. Perchlorates
may offer a potential energy source
for microorganisms, for example, and
therefore potential to grow life.
Other studies, such as at the
UK Centre for Astrobiology at the
University of Edinburgh, are less
positive about perchlorates. One
test exposed cells of the bacterium
Bacillus subtilis, a common spacecraft
contaminant, to perchlorates and UV
radiation at levels similar to those on
or near Mars’ surface.
The cells lost viability within
minutes, and even more quickly
in Mars-like conditions; and their
lifespan decreased to 60 seconds
when iron oxides and hydrogen
peroxide, two other common
components of Martian regolith, were
added to the mix.
The data concluded that the
probable survival of biological
contaminants on Mars’ surface is
low. Through the combined effects
of at least three components of the
Martian surface activated by surface
photochemistry, the landscape of the
red planet is more uninhabitable than
previously thought. !
But how
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