Space advances water resources management on Earth

This year, UN-Water has selected “Water and Wastewater” as a theme, recalling the "symbiosis between water and wastewater in the quest for sustainable development".

At ESA's Space for Earth, we highlight how space applications can benefit the sustainable management of the world's water resources and particularly how technologies developed for space have transformed the treatment of wastewater.

Increased proportions of untreated wastewater are one of the root causes of today's water security crisis, and the resulting decline in water quality has a significant impact on human health. Access to clean water and sanitation for all is also on the list of the UN sustainable development goals (SDGs) and lies at the root of many of the other SDGs.

Water is also a significant research topic in space exploration. Evidence for water in places other than Earth is a key element in our quest for habitable planets and for a better understanding of the origins of our solar system.

Moreover, water reuse is fundamental for astronauts on board the International Space Station, where wastewater and urine are recycled into drinking water, reducing the amount of supplies that need to be transported to the station.

Indeed, humans in space require high amounts of metabolic consumables (e.g. oxygen, water and food). It is estimated that for a mission to Mars, for example, about 40 tons of consumables would be required. In order to reduce the weight and provide more autonomy, ESA has been developing recycling technologies for many years.

These developments concern functional units (e.g. grey water treatment units), up to full recycling systems (i.e. the MELiSSA project). MELiSSA (Micro-Ecological Life Support System Alternative) is a self-sustaining eco-system to support life indefinitely in a closed environment, which has been initiated in the early 1990s. Water processing, whereby all water is captured and purified to be consumed again, is essential to the good functioning of the system.

ESA has developed a working prototype of the water recycling unit with a focus on grey water (i.e. washing and kitchen wastewater). Since 2005, this system has been operational at Concordia, the French-Italian research facility in Antarctica. More recently, a wastewater recycling unit based on MELiSSA has been installed at the University of Kenitra, Morocco, providing safe drinking water to the local community and helping to achieve the sustainable management of water in the region.

Looking at the terrestrial challenges and the new environmental requirements, these technologies have also attracted interest from commercial companies. Already a few examples of implementations are around: nitrification units (e.g. Biostyr), sanitation hubs, brewery and wine producers, ...