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SaRY Project to Help Develop Circular Life Support Systems in Space and On Earth


Marta Lebron

The SaRY (Salinity Reduction of Yellow Waters) activity started on September 1st 2021 in the frame of the MELiSSA project of the European Space Agency (ESA). MELiSSA (Micro-Ecological Life Support System Alternative) is the European project of circular life support systems. It was established to gain knowledge on regenerative systems, aiming to the highest degree of autonomy and consequently to produce food, water and oxygen from mission wastes.

SaRY Project

The SaRY activity is performed together by QinetiQ and our partner companies Hydrohm and Firmus France. SaRY represents the next step in water resource optimization and nutrient recovery from urine.

To date, urine recycling during space missions has mainly focused on achieving high water recovery efficiencies, at the expense of energy costs and of the other valuable elements found in urine. However, in the absence of resupply possibilities, long-term crewed space missions will require the use of all available resources. In a view of circular economy promoted by MELiSSA, urea (as a nitrogen source) and essential elements of urine (i.e., phosphorus, potassium, calcium) shall be recycled for food production (e.g., cultivation of microalgae and higher plants) or other bioprocesses (e.g., nitrogen gas production). Among urine components, sodium chloride acts as a biocide: it inhibits microorganisms and prevents the direct use of urine in bioprocesses.

Therefore, the SaRY activity studies how to reduce the high concentration of sodium in urine in an energy-efficient way. The SaRY team will perform a trade-off of relevant technologies compatible with space constraints, and demonstrate the adequacy of selected technology(ies) through testing. The proposed urine salinity reduction process will be evaluated with regards to sodium chloride rejection, recovery of valuable urine elements, and toxicity of the output product towards bioprocesses. While the SaRY process is initially conceived for space use, it is also expected to contribute significantly to salinity reduction of waste waters on Earth.