Red leaf lettuce grown under different light regimes in the University of Guelph's Controlled Environment Systems Research Facility produced leaves of different colours and tastes. Submitted by Mike Dixon
If Mike Dixon's dreams come to fruition, Canadian science will spawn the first strawberry or cherry tomato that sprouts on the moon or a planet in our solar system.
Deep inside his high-tech research facility at the University of Guelph in southern Ontario, the environmental biologist and his team have been laying the groundwork to help make that happen by trying to find the ideal wavelengths of LED light to make certain plants more productive.
Over the next few hundred years, says Dixon, a professor and chair of Guelph's environmental biology department, humans will "march around on Mars and explore Mars on a large scale."
When that happens, he says,"we'll need very significant environment control systems and life support systems based on plant biology, because you can't resupply Mars with groceries very efficiently."
Dixon knows there are hurdles to conquer in science, as well as with government research funding, before any tomato or strawberry grows in a carefully controlled climate hundreds of thousands of kilometres from our own little planet.
For now, though, he is focusing on the potential of LED lighting to optimize plant growth, and is finding Earth-bound applications for his research in everything from growing food in the harsh climates of the Canadian North and Kuwait to the burgeoning medical marijuana industry.
"The field of medical marijuana, should it take off as it probably will in some form or other, has so many opportunities to deploy these kinds of technologies, " Dixon says.
"Everything we do in the research facility is pulled by that technological challenge of going to the moon and growing a plant, but it is driven entirely by the technology transfer and commercialization opportunities that our industry partners find."
No fine dining
For those astronauts who have eaten their share of freeze-dried and processed food in space, the potential Dixon's research holds is high.
"We're looking forward to the day when astronauts can actually eat fresh fruit and vegetables for the nutritional value, for the psychological value and also just because it's closer to home cooking and provides good psychological support," says Bob Thirsk, a retired Canadian astronaut who spent 205 days in space over two missions, including a 2009 stint on the International Space Station.
"Living aboard a spacecraft is living in an isolated and confined environment. It's certainly not like staying at a five-star hotel. It's functional. It's rustic," he says.
"For short periods of time that's fine, but after a long period you want some connection with Earth. You want the sights, the sounds, the smells, the tastes of Earth because we're all human beings and that's where we're from."
Thirsk is well aware of the many environmental challenges posed by the prospect of trying to grow food in space, an environment that would be too expensive and impractical to try to recreate growing conditions identical to those found on Earth.
A bacterial infestation could also wipe out a crop, a real problem on a spaceship, where there would likely be little in the way of backups.
There would also be worries about the air and water filtration system on a space station. Pesticides and fertilizers would have to be used to get the most from a crop yield, and you would have to filter that out before the astronauts were exposed to the air and water again.
Can't wash it all away
"We live in an isolated and confined environment" aboard a space station, notes Thirsk. "You don't have a constant fresh wind blowing in off the Pacific that can wash that all away."
He sees great potential in the LED research that Dixon and his team are undertaking at Guelph's Controlled Environment Systems Research Facility, noting that LEDs provide considerable light intensity.
"If we had to think about preparing the first mission to Mars next year, I'm sure the light source would be LEDs. I think aeroponics' — growing plants in air or mist without soil — "is probably something we would consider as well."
The potential Dixon sees in LEDs, something he describes as a "key technical component of the artificial lighting required to grow plants in rather strange environments," is not something he could have contemplated half a decade ago.
"The electrical efficiency of these systems and the intensity you can get out of LEDs now is far beyond what I would have thought possible as little as five years ago," he says. Technological advances in street lighting and automotive lighting have helped pave the way for the research he is doing.
In a lab equipped with customized chambers, he's looking for a "magic recipe" of light — the ideal wavelengths and amounts of red or blue or amber or ultra violet light — that will contribute to the most ideal growing conditions possible, pushing photosynthesis and the productivity of the plants.
"The permutations and combinations are endless, so even though we're starting with a fairly well-educated guess as to how to construct the ideal spectrum, the plants confound you because they adapt."
In his lab, lettuce is used as a guinea pig because it grows easily and quickly. But the target crops are "relatively high value fruit crops" like cherry tomatoes and strawberries.
"The so-called candidate crops for space exploration are exactly what you would think is appropriate for a nutritional, well-balanced, psychologically appealing diet, vegetarian diet of course," says Dixon.
For all the work that has already been done, Dixon says it is still "early days" in the research agenda, but he remains optimistic food could grow beyond Earth within a couple of decades.
"I would say in the next 15 to 20 years it's certainly within the bounds of technical possibility that humans can being growing plants, doing plant science experiments, on the surface of the moon in preparation for life support requirements on Mars."
And for him, Canada is uniquely placed to lead the way in that endeavour.
"We currently lead the world in research and technology developments for that little niche field called biological life support."
But government funding is still in short supply.
"The Canadian Space Agency limps along on a budget that wouldn't change the tires on the space shuttle, so it's quite remarkable they achieve what they do," Dixon says.
(A 2012 report commissioned by the federal government said that the space agency's core budget had decreased over the previous decade, falling from $325.8 million in 2001-02 to $285.8 million for 2012-13.)
Dixon would like to see the agency able to do more, and sees a potential spin-off if space research received broader support.
''We should be just chomping at the bit to create an economic engine out of something as relatively noble as space exploration."
But he does realize it won't be an easy road with instant results.
"We've got a lot of lessons to learn yet, so it's not going to be an overnight success. We'll incrementally advance the contributions that biological systems make to space exploration life support requirements over the next 100 years."