Improving upon the sun: LED lights fuel plant growth in space

Michael Dixon, University of Guelph

If you’ve ever seen the film The Martian, you’re familiar with “plants in space.” The protagonist in the film, played by Matt Damon, successfully harvests potatoes on Mars to feed himself when he’s stranded on the planet.

Far-fetched? Not at all.

Here at the University of Guelph in our Controlled Environment Systems Research Facility (CESRF), we’ve been investigating controlled-environment plant production and how best to get the most out of plants in terms of food, oxygen, fresh water and carbon dioxide scrubbing — in other words, human life support —for decades. Since the mid-1990s, we’ve been home to the Space and Advanced Life Support Agriculture (SALSA) program.

These research activities form Canada’s contribution to the niche field of space exploration known as “biological life support” — or plants in space.

Research and technology developments in this field include:

Among the more recent tools in the pursuit of high-density production of a range of crops are light-emitting diodes (LEDs) as a source of photosynthetic energy. In our research facility, we’re working to refine and perfect LED technology.

The advent of ever-increasing intensity and efficiency of LEDs has expanded their use beyond cars and street lights. We now routinely consider LEDs as supplemental, or even sole-source, lighting for plants.

LEDs have a unique narrow wave band of light that represents a small sub-section of the solar spectrum. There are many examples of LEDs that virtually fill the spectrum of visible light and beyond to include ultraviolet bands and far-red to infra-red components.

We know quite a bit about how plants respond to various wavelengths, and certain combinations of wavelengths of light,