Food for thought on mission to Mars

Michelle Bennett is an aspiring astronaut but is also conducting research for Nasa on the use of bog plants for food production…

Michelle Bennett is an aspiring astronaut but is also conducting research for Nasa on the use of bog plants for food production on a mission to Mars

'BOG PLANTS! That's how I got into Nasa," says Michelle Bennett, currently head of the Department of Applied Science at the Limerick Institute of Technology.

"It was a pure fluke. I left samples in airtight containers in my father's garage and forgot about them. When I found them again a year later, they had changed but they were still alive.

"The question then was, what would happen if we put them in an enclosed container in space. That's when I came up with the idea of using them in enclosed life systems used in space flight, the International Space Station and planet colonisation models," she says.

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Now it looks like these humble mosses could soon be doing for astronauts what they have long been doing for Ireland's bogs - keeping them fed and watered.

Sphagnum mosses are what make a bog a bog. Without them, there would be no bogs. They form a living skin that covers a floating mass of partially rotten plant material that can be several metres deep.

When the moss dies, it becomes part of this under layer. The living moss is capable of absorbing up to 20 times its own weight in water. This water is used to support a world of microscopic plants and animals, which in turn provide food for all the organisms living in the bog, from midges to frogs.

Providing enough food, water and oxygen for those humans brave enough to consider long-duration space flight, on the other hand, is not so easy. Previously, spacecraft life-support systems were designed for short missions and relied on stored sources of water, food, and oxygen.

On longer missions, however, storing the necessaries would not be economically or logistically feasible.

Therefore, designing new technology to cultivate crops in space is vital to human exploration of the Moon and Mars, which is where Bennett and her bog plants come in.

"What I discovered that day in my father's garage was an absolutely new, accidental discovery. Not only were the plants still alive but they had survived in a closed system without the normal requirements for growth found on the bog."

Since then, Bennett, who hails from Clara, Co Offaly, has been working with scientists at Nasa to discover how the unusual qualities of sphagnum mosses might be used in space.

"Sphagnum mosses have really proved to be perfect for space flight," Bennett says. They are a perfect growth medium for plants, are slightly antimicrobial and can also be used for waste treatment.

"They are natural filters. The nutrients in urine, for example, can be filtered out to feed the plant."

Tests using the mosses have been a great success. Lettuce was grown in sphagnum according to Nasa test conditions. Four of five planting trays used sphagnum as a growth medium. An artificial urine was used as a food source in two trays and two trays were supplied with a standard nutrient solution. The remaining tray acted as a control using standard Nasa growth medium and standard nutrient solution.

"The results were very exciting. It was the first time lettuce has been grown in such a system using urine to produce a healthy crop," says Bennett.

And it is very likely that these mosses will make it into space. "Research is under way for the development of a flight test for sphagnum," Bennett says. But she is not giving away any secrets. When asked about the species of sphagnum, she said: "Can't say."

In other work, Bennett is looking at how nutraceutical levels might be increased in crops likely to be grown in space, like lettuce, peppers, radishes and onions. "This would enrich astronauts diets and strengthen their immune systems," she says.

And, of course, Bennett may very well end up eating a urine-fed lettuce leaf herself one day. She has applied to the European Space Agency's Astronaut Programme and may be Ireland's best hope of having an astronaut any time in the near future.

"Being an astronaut is a long-term dream. Having worked at Nasa was a dream come true. But this is something special. If they accept me into at least one of the rounds, I can show them what I'm made of," she says.

And then Clara really will have a home-grown celebrity to boast about.