“MARS COLONISTS
WOULD NEED TO LEARN
TO BE SPACE FARMERS!”
[ FOOD AND NUTRITION ]
Weightlessness presents several problems for eating in space.
Without gravity, crumbs are a real health hazard, floating
in the air to be inhaled into your lungs. And the redistribution
of bodily fluids mean tissues in your head swell and you struggle
to smell or taste things properly – just like having a cold.
So astronauts often prefer spicy foods, and tend to eat breads like
tortillas that don’t crumble. Practically all the food on the ISS
is pre-packaged and is simply rehydrated and heated up –
imagine eating nothing but airline food for months on end.
Every six months or so, a resupply vessel is launched from Earth
to deliver essential stocks. It’s stuffed with food, water, spare
clothes, fuel, oxygen and so on.
But, for longer space missions, such as a Moon base or mission
to Mars, constant resupply would be prohibitively expensive or
outright impossible. We’ve seen already how hibernation
technologies in the future may allow crews to sleep on the way
to Mars, and so relieve the necessity for a large amount of travel
food, but, when they wake up on arrival, food will once again
be a priority. Instead of relying on deliveries from Earth,
Mars colonists would need to learn to be self-sufficient –
to become space farmers!
In the film The Martian, Matt Damon’s character cultivates
potatoes in regolith (the powdery rocky surface) mixed with his
crewmates’ excrement to provide nutrients. And this isn’t too far
off the truth of what space agencies are considering for habitats
on Mars (minus the poo). For example, last year, scientists at
Wageningen University in the Netherlands made simulated
Martian soil and tested which crops could be grown in it.
They found that tomatoes, peas, radishes, rye and rocket grew
well, but spinach struggled. They are now testing whether
potatoes and beans could be cultivated on Mars. The environment
is so hostile you would need to provide pressurised, inflatable
greenhouses, but scientists remain hopeful that future Martians
could live off the land.
And what about meat? Keeping farm animals on an off-world
base would be enormously difficult – they would take up a huge
amount of space and resources. So instead, future space explorers
are likely to be mostly vegetarian, and get small amounts of
animal protein from bugs. Insects can be reared in high-density
and fed on plant waste. Taikonauts on China’s Tiangong-2 space
station have been raising silkworms, which could serve as
a protein-rich source in the future. So perhaps future Martians
will be eating bug burgers in home-grown wheat buns with
lettuce and tomato!
55Prof Lewis Dartnell is an astrobiology researcher at the University of
Westminster and author of The Knowledge: How To Rebuild Our World
After An Apocalypse.