Enabling & Support
02/04/2026
50 views
3 likes
As humanity prepares for long-duration missions to the Moon, Mars and beyond, the challenge of sustainable living in space becomes increasingly urgent. ESA’s “Sustainable Future: Advancing Circular Life Support Systems” campaign selected five innovative activities that aim to transform waste into valuable resources, bringing closed-loop systems for space exploration closer to reality.
For decades, ESA’s MELiSSA project has worked to develop regenerative life support systems that can produce oxygen, water and food whilst recycling waste. Now, through the Discovery element of ESA’s Basic Activities, five teams across Europe are exploring novel approaches to enhance the circularity of these systems, addressing critical gaps in biomass valorisation, air quality and resource efficiency.
The challenge of closing the loop
A view inside the MELiSSA pilot plant at the University Autònoma of Barcelona
Current regenerative life support systems can achieve impressive recycling rates, but significant challenges remain. The MELiSSA loop, for instance, can convert around 70% of biomass into useful products, but the remaining fraction – particularly lignin and other non-degradable components – has proven difficult to process. Meanwhile, maintaining air quality in closed environments and maximising the value extracted from every gram of biomass are essential for truly sustainable space habitats.
The five activities selected in July 2024 tackle these challenges from different angles, exploring everything from biopolymer production to air purification using microalgae.
Transforming waste into materials
Two Belgian teams are investigating ways to create valuable materials from waste streams and biomass. VITO is exploring biopolymer manufacturing using Cupriavidus necator, a versatile microorganism capable of producing polyhydroxyalkanoates (PHA) and polylactic acid (PLA) from various waste products including volatile fatty acids, lactate, ethanol and CO2. These biodegradable polymers could be used for applications ranging from medical supplies to food packaging and 3D printing – all produced from resources already present in a closed-loop system.
VITO is also working on a complementary approach: using reactive extrusion to maximise the valorisation of lignocellulosic biomass. This compact system could work alongside the MELiSSA bioreactor, separating sugars from lignin more efficiently than current methods. Whilst the sugars would fuel microbial processes, the lignin – with its flame-retardant and UV-blocking properties – could become feedstock for developing materials needed in extra-terrestrial environments.
From algae to packaging
Blue Horizon in Luxembourg is developing edible bioplastic films from Limnospira (commonly known as Spirulina). These thin films could serve multiple purposes: packaging food or other materials, adding variety to crew meals, or easing the handling of powders such as detergents. The team is also investigating whether waste material from 3D printing with Spirulina-based thermoplastics – another technology under development – could be recycled into these films, further closing the loop.
Enhancing air quality and plant health
Redwire Space is investigating whether their GreenLung technology, originally designed to remove carbon dioxide and volatile organic compounds from air, can also eliminate airborne viruses. By testing the photobioreactor component of GreenLung with model virus particles, the team aims to demonstrate a natural, cost-effective method for maintaining air quality in closed environments – without the drawbacks of traditional systems such as high operational costs or the production of hazardous by-products like ozone.
Meanwhile, Nantes Université is exploring how Spirulina biomass from the MELiSSA loop could be repurposed for plant protection and growth enhancement. The team is testing whether whole Spirulina biomass or its fractions – with or without enzymatic hydrolysis – can provide biocontrol and biostimulation properties for crops like tomato and lettuce. This waste-to-product approach could increase the overall circularity of the MELiSSA loop whilst opening possibilities for terrestrial applications through industrial residue valorisation.
Looking ahead
The five activities represent diverse approaches to circular economy challenges in space, from fundamental biological processes to practical applications. Each team is now coming to the end of 18-month studies advancing these concepts from initial ideas towards technologies that could one day support sustainable human presence beyond Earth.
The technologies developed through this campaign could also find applications on Earth, contributing to circular economy goals and sustainable resource management in terrestrial contexts. From bio-based plastics to efficient biomass processing, these space-driven innovations may help address environmental challenges closer to home.
Like