Soapbox Science

How To Grow A Garden On Mars

Louisa Preston is a Postdoctoral Research Associate at The Open University and TED Fellow. She is currently designing a Mars Gardening Interactive exhibit to showcase the features and issues raised in this blog. Follow her on Twitter @LouisaJPreston.

I grew up surrounded by science fiction; in books, in films, and on the television. Every scene showed humans travelling around in spaceships visiting aliens that lived on other planets, living their day to day lives in the vacuum of space and setting up new cities on foreign worlds. I never questioned this; it was, after all, fiction. However, for our generation and the one quickly following behind us, science fiction is becoming a reality on a daily basis. We have witnessed the discovery of the Higgs Boson, watched rovers wander across the surface of Mars and have discovered planets orbiting other stars. But we might be only decades away from discovering life on another planet and even observe humans leave Earth and inhabit another world during our lifetime. As I said, this is all science fiction isn’t it? Well not anymore…

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This colour image from NASA’s Curiosity rover shows part of the wall of Gale Crater and the dusty dry landscape that would provide the backdrop for any future Mars gardens. Credit: NASA/JPL-Caltech/MSSS

A number of space agencies are focusing on space architecture and designing buildings for human habitation on the Moon and Mars. But what interests me, is the possibility and design of Space Agriculture or ‘AstroGardening’, particularly on Mars. If we want to live on another planet we will need, amongst many important things, food and water. Not shipped to us from Earth (it would cost $80,000 to transport 4 litres of water to the Moon, let alone Mars) but sustainably grown so that the first settlers and then future generations can live off the land. This means we need gardens, and lots of them!

Gardening on Mars would provide a long-term food source for future human colonies and could provide over half their required calorie intake through the growth of tomatoes, potatoes and other fruit and vegetables. Plants such as asparagus, potatoes and marigolds have already been shown to grow in Mars-like soils, plus seeds of radish, alfalfa, and mung bean can sprout in the carbon dioxide atmosphere of Mars. Gardens also help to recycle nutrients, provide drinking water, and use the carbon from Martian atmospheric carbon dioxide to produce oxygen through photosynthesis. Gardens could even, in the long term, provide building materials such as wood and bamboo. With the incredible advances being made in the space sciences and planetary exploration, the idea of harvesting crops and planting gardens in space is actually not that far-fetched.

Plants need water, oxygen, sunlight, nutrients and relatively comfortable temperatures, but none of these are currently found on Mars in abundances that suit the growth of a garden. Mars, our red and dusty next door neighbour, has a thin, low pressure CO2-rich atmosphere (we have by comparison a breathable nitrogen and oxygen-rich atmosphere); extremely strong solar radiation and very cold temperatures (average of -63 °C). With only 38% of the gravity of the Earth and ravaged by global dust storms, this is a world that would not support most of the plant life on the Earth, nor would it be a safe environment for humans to inhabit without artificial help. Any garden would need protection in the form of a greenhouse or geodesic dome that could keep the crops sheltered from extreme UV radiation whilst still allowing enough sunlight for growth to get through. This dome would need to be anchored into the regolith to provide support and protection against the strong Martian dust storms and dust devils.

Sketch of an ‘AstroGardening’ robot within a theoretical garden on Mars. Credit: Vanessa Harden.

Sketch of an ‘AstroGardening’ robot within a theoretical garden on Mars. Credit: Vanessa Harden.

The crops would need to be kept warm whilst surrounded by the cold climate of Mars. This heating of the greenhouse would require energy, potentially from solar panels arranged outside the habitat and heating filaments underneath it. Liquid water is needed for irrigation of the plants and for human consumption, but the water on Mars is mainly frozen beneath the surface. Would we mine this ice and melt it? Another, and perhaps the most important, consideration is who would do all of this work? Brave human pioneers kitted out in space suits or could we design speciality AstroGardening robots? These are all important aspects of long-term human habitation of Mars that need to be tested and perfected before we arrive, but thankfully most of these can be investigated whilst safely here on the Earth in Mars analogue environments.

I am currently working as part of the Mission Support Team for The Hawai’i Space Exploration Analog and Simulation (HI-SEAS) mission. As part of the mission we are testing new food preparation strategies for long-term space exploration, such as cooking on the surface of Mars, from the confines of a geodesic habitat in an abandoned quarry on the northern slope of Mauna Loa in Hawai’i (check out their site and personal blogs throughout the mission here). HI-SEAS is funded by a grant from the NASA Human Research Program allowing six ‘astronaut’ crew members to live under Mars exploration conditions in the habitat for 120 days. One crew member is TED Fellow Angelo Vermeulen, an artist, biologist and space scientist who is conducting his own research on remote operated gardening whilst in the simulation. This is basically gardening using robots that can take care of the crops with only minimal human interaction. This study is a wonderful step towards planning how we might garden on Mars and set up a future human outpost on the planet. Perhaps one day, this won’t just be science fiction!

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