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 prepackaged 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 offworld 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!
“MARS COLONISTS WOULD NEED TO
LEARN TO BE SPACE FARMERS!”
RIGHT: ISS astronauts rely on deliveries of fresh food to top up their supplies, but this wouldn’t be feasible on a Mars or Moon base
BELOW: From left to right, radishes grown in Moon soil substitute, Mars soil substitute, and Earth soil
Prof Lewis Dartnell is an astrobiology researcher at the University of Westminster
and author of The Knowledge: How To Rebuild Our World After An Apocalypse