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WOULD YOU EAT A TOMATO GROWN WITH YOUR OWN PEE?

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The MELiSSA (Micro-Ecological Life Support System Alternative) Pilot Plant is an artificial closed loop life support system initiated in 1995 at the Universitat Autònoma de Barcelona by the European Space Agency. With a projective impulse, the project is intended for future long-term manned space missions, which would enable the development of self-sustaining planetary bases on the Moon or Mars. To this end, at the core of the agency’s artificial ecosystem is the recovery of food, water and oxygen from waste, in the form of feces and urine, carbon dioxide and minerals (European Space Agency. MELiSSA), for a closed liquid and gas loop which attains one hundred percent of oxygen requirements and at least twenty percent of food necessities for a single human. (Poughon, Farges, Dussap, Godia, Lasseur. Simulation of the MELiSSA closed loop system as a tool to define its integration strategy, 1392–1403)

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With five interconnected components, each component contains a set of processes that surround a central reactor. Compartment (1) one collects the waste (feces, urine, paper), produced by the crew housed at compartment
(5) five, along with plant waste and microbial biomass exhausted from compartment (4) four – responsible for food generation, oxygen production and water purification. Subdivided in two secondary sections, C4a houses edible blue-green algae; C4b contains higher plant production for food the recovering of water for human consumption. The plants in C4 require the mineral nutrients, nitrogen, and carbon dioxide, which are recycled through the processes from the first compartment. Finally, compartments (2) two and (3) three undertake biotransformation steps; while the former is devoted to the removal of fatty acids from the liquid, the latter converts ammonia to nitrate. Prior to fastening all five sections, each component underwent a series of isolated tests, followed by a second experimental stage for the integration of all components in a closed circulatory loop.

Although the project’s status as an on-going experiment limits conclusive results at this time, the MELiSSA Pilot Plant’s 2008 launch of forty rats – a simulation of the oxygen demands for one human – enabled researchers to observe that it was not possible to meet target goal of one-hundred percent oxygen closure. (Poughon, Farges, Dussap, Godia, Lasseur. Simulation of the MELiSSA closed loop system as a tool to define its integration strategy, 1392–1403) Yet, with every additional stage of experimentation, elements of the loop are improved and results become closer to the target of fully recycling all chemical elements housed within the system. The MELiSSA Pilot Plant is expected to meet its final objective in future pilot tests without radically changing its system components.

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KEYWORDS: Biotransformation, European Space Agency

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KEY FAILURES

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OXYGEN CLOSURE: 2008 launch of forty rats – a simulation of the oxygen demands for one human – enabled researchers to observe that it was not possible to meet target goal of one-hundred percent oxygen closure.

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