1) Throughout this text, I will use the word “terrestrial” to refer to the planet Earth as opposed to “space”, which slightly pains my aquatic biologist heart.
2) As a lot of the talks had some link with plant sciences, I feel like, despite this entry being space or lake focused, it also has a place on this green and leafy blog!
This week, I was lucky enough to go to Lausanne, a small Swiss city on Lac Léman, to attend the MELiSSA Workshop. What is MELiSSA? As an ecologist, it is unlikely that you are acquainted with this European Space Agency (ESA) project, which stands for Micro-Ecological Life Support System Alternative. It was created in 1989 (read more on how it began here) and brings together European and Canadian partners from 13 different countries in an attempt to fulfill human needs in outer space via the development of life in closed systems. The main ideas include: recycling waste and carbon dioxide aboard spacecraft by using bacteria; and producing food, water, and oxygen in a regenerative way to keep costs low. Put in their words, it aims “at a total conversion of the organic wastes and CO2 to oxygen, water and food”.
Terrestrial lake eco-loop. Copyright: ESA.
What drew me to this workshop is that this closed loop is based on lake ecosystems, as depicted in the diagram above. Whether lake ecosystems are truly closed is debatable, and in my opinion is rather incorrect (I still believe in the importance of allochthony!). However, in the natural terrestrial environment, lakes are probably the system that comes nearest to the idea of a closed loop, due to their ecological isolation and the limitation of external inputs. In lakes, the processing of waste products via plant and algal metabolic activity fuels the regeneration of food, clean air, and pure water – and this is why the lake aquatic ecosystem is used as a model for MELiSSA.
Concretely, they try to reproduce this via the following compartmentalization of tasks:
||Organic waste degradation & solubilisation by thermophilic anoxygenic bacteria
||Carbon compounds removal by photoheterotrophic bacteria
||Nitrification by nitrifying bacteria
||Food and oxygen production by photosynthetic bacteria
||Food, oxygen and water production by higher plants
Which recreates the loop:
The 5 compartments of the MELiSSA loop. Copyright: ESA. See Godia et al. (2002).
The two-day workshop brought together 140 participants from 21 countries, from academia and industry, who discussed solutions to issues associated with space travel. With more than 40 speakers, you can imagine the days were long, but invigorating, and made even more enjoyable by the quality of the tea breaks and meals (a giant parmesan filled with rice for lunch!). To give you an idea of the breadth of topics discussed, here are the titles of the 6 sessions that made up the workshop: 1) Waste processing, 2) Water recycling, 3) Air recycling, 4) Food production & preparation, 5) Chemical & microbial safety and 6) System tools. These covered subjects as seemingly divergent as food production and new food sources, clean showerheads, anaerobic digestion, human feces disposal, and hydroponic plant-fish interactions.
My thoughts about space research have always been that the money put into it could instead be used to solve terrestrial problems. Scientific terrestrial problems – feeding the world, conserving biodiversity, predicting the effects of global change – urgently need solutions. As an aquatic biologist, I have heard many times that the deep sea has been infinitely less explored than the surface of the moon. Why should we keep investing into space research then? Is sending men to the Moon or to Mars a sci-fi dream, a demonstration of our technological power, or a serious and, perhaps in the future, necessary escape from a damaged planet Earth? Whichever of these it may be, I have come to understand that spending money on what may first sound utopic is actually beneficial to our planet in much more concrete and terrestrially applicable ways than I ever imagined. What the conference taught me is that there’s a kind of closed loop of ideas: space research takes from ecology, and vice versa.
And indeed, there is no doubt that the vast majority of the research and new technologies discussed throughout the workshop aims to bring more sustainable innovations or alternatives to extant ones. Ultimately, the idea of the closed loop is about recycling: anything that is part of the loop needs to be reused, recycled, and regenerated. By incorporating this ecological idea into technological principles, the closed loop can also yield a new form of economy, a “circular economy”, whereby waste is limited and the value of products is retained. Of course, I am skeptical about some of the proposed projects – too utopic, not financially viable, no real advances made. For instance, I would love to dive in underwater gardens (large glass tanks maintained at supposedly constant temperature), but I don’t understand how they could ever be part of the solution to feed the world.
In addition to this little inner discussion I had with myself, what I can really take home from this meeting is a lot of new knowledge on microbial communities – how they interact among themselves but also with their environment, how they process nutrients, and how they can be studied. One question that particularly triggered my interest is whether prosperous and diverse microbial communities that can auto-regulate are less harmful, or risk-prone, than disinfected zones whereby resistant microbes have the potential to thrive and be pathogenic? I also saw how my current research could be applied in various ways. As a PhD student, not getting results can sometimes distract you from the focus of your project, and leave you wondering why you are there and for what purpose. Seeing the potential – both theoretical and applied – of my research, gave me a surge of motivation and new ideas. It also pushed me to think of subjects that had never even crossed my mind, namely the number of issues associated with space travel – microbial contamination, food and water supply, waste removal, breathing clean air…
Finally, I would like to say that my most valued moments of the workshop were occasions to exchange ideas with Mark Nelson. Mark was part of the first Biosphere 2 mission from 1991 to 1993 (if you don’t know about this 2-year closed loop experiment, in Arizona, with 8 crew members, I recommend reading about it) and is one of the founders of the Institute of Ecotechnics. I have to admit I was a little nervous about attending the workshop, fearing that I would feel out of place amongst all these engineers and businessmen. In the first few minutes upon my arrival though, I met Mark and felt like I was in the right place, and that I could learn a lot from this workshop. Mark is an ecologist – the academic son of H.T. Odum, and the academic grandson of G.E. Hutchinson – and has been involved with MELiSSA for many years. It was truly engaging to discuss space exploration, closed systems, systems ecology, urbanization and many other exciting or demoralizing topics. Special encounters like these can give large events a whole other dimension.
In the end, I came to the conclusion that environmental thinking can successfully be integrated into space activities, and can promote synergies between space and terrestrial research. I am glad I attended this workshop, which gave me space for thought as well as a taste of something new. And to open up the discussion: how do you feel about closing the loop?