Orbital dynamics
Perhaps one of the best factual aspects of the film is the
accuracy of the travel time between Earth and Mars.
While some science fiction films have the characters
whizzing from point to point, “The Martian” reveals the
brutal reality of spaceflight: It would take about eight
months to get to or from Mars with current technology.
“This is not just a story, the author has done real
computations,” Rudi Schmidt, ESA Project Manager for
Mars Express and also a consultant on the film, told
IFLScience.
Fact or fiction? Fact
Future manned Mars missions will use a constantly
orbiting spacecraft akin to Hermes (shown).
Martian soil
In the movie, after becoming stranded on the surface,
Watney resorts to using a combination of his own
excrement, water, and Martian soil to grow potatoes.
But would Martian soil actually be of any use? Isn’t it
sterile and dead?
“In terms of basic mineral content and chemical
content, yes it would be possible to grow plants
in Martian soil,” said Lavery. “We actually have
experiments going on right now using simulated Mars
soil, and it indicates that’s a very realistic idea.”
Fact or fiction? Fact
Mmm, delicious.
Radiation
Spending any prolonged amount of time in space,
we’re talking months or years, runs an increased
risk of developing a radiation-related sickness,
such as cancer. Modern astronauts stay in the
safe confines of Earth’s magnetosphere, while
the Apollo astronauts spent just a few days at the
Moon.
But on Mars, each Ares crew was spending up to a
month on the surface in the movie. It’s likely that
the habitat as depicted in the film might be a bit
different on a real future Mars mission; it might
be necessary to partly submerge it in the ground,
providing natural protection from radiation.
“The reality is I think people will go underground,
to protect against radiation from the Sun,” said
Schmidt. “The structures will be on the surface,
but machines will be used to protect them with
Martian sand.”
And what about Watney, who spends more than a
year on the surface, often with nothing more than
his spacesuit for protection? Well, although the
radiation levels on Mars are less than expected,
it’s possible he would have considerably increased
his risk of cancer, although he was unlikely to have
experienced any immediate effects during his stay.
We’ll call this one a tie.
Fact or fiction? Tie
Taking off from Mars
To leave the Red Planet, each Ares crew uses
a Mars Ascent Vehicle (MAV). In the book, it’s
explained how this plucks methane out of the
Martian atmosphere to create fuel. The rocket then
accelerates to an orbital velocity that allows it to
rendezvous and dock with the Hermes spacecraft,
which then brings the astronauts back to Earth.
Feasible?
At the moment, no. NASA readily admits this is one
of the biggest obstacles to future Mars missions.
They just simply don’t know the logistics of taking
off from Mars, and all the unknowns that brings
with it. Just think of taking off from Earth; although
there are hundreds of launches every year, a few
now and then end in failure. Mars has 30% of
Earth’s gravity and a sizable atmosphere, so it’s not
going to be easy. “Taking off from Mars is one of
the biggest problems we’re working on right now,”
said Lavery.
THE CLAPPER 2015 - 2016 43
PHYSICS
DEPARTMENT