ESA is funding HOBI-WAN, a pilot to test Solein — a protein powder produced from air, microbes, electricity and nutrients recovered from recycled urine and habitat waste. Developed with Solar Foods, the project will first validate the production process on Earth and aims for later trials on the International Space Station. ESA says the technology could increase autonomy, resilience and astronaut well-being on long Moon and Mars missions.
ESA to Test ‘Solein’ — Protein Made from Air and Recycled Urine for Long Space Missions
ESA is funding HOBI-WAN, a pilot to test Solein — a protein powder produced from air, microbes, electricity and nutrients recovered from recycled urine and habitat waste. Developed with Solar Foods, the project will first validate the production process on Earth and aims for later trials on the International Space Station. ESA says the technology could increase autonomy, resilience and astronaut well-being on long Moon and Mars missions.
06:04 AM, 11/11/2025Science
ESA launches pilot to develop protein from air and recycled urine
The European Space Agency (ESA) has begun funding a pilot program to evaluate a novel protein powder called Solein, produced using air, microbes and electricity. The technology is being developed in partnership with Solar Foods, a Finnish food-technology company, and aims to recycle resources generated by crew members and life-support systems on long-duration missions.
The process relies on hydrogen-oxidizing bacteria that convert basic inputs — hydrogen, oxygen and carbon dioxide — into microbial biomass. Nitrogen and other nutrients recovered from recycled urine and habitat waste streams provide the essential building blocks the microbes need to produce a complete protein powder.
HOBI-WAN: from ground tests to the ISS
The first phase of the program, called HOBI-WAN (Hydrogen Oxidizing Bacteria In Weightlessness As a source of Nutrition), will develop and validate the production method on Earth before any experiments are performed aboard the International Space Station (ISS).
“This project aims at developing a key resource which will allow us to improve human spaceflight’s autonomy, resilience and also the well-being of our astronauts,” said Angelique Van Ombergen, ESA’s chief exploration scientist. “For long-duration missions to the Moon or, one day, to Mars, we will need innovative, sustainable solutions to survive with limited supplies.”
ESA and its partners emphasize that the work will include rigorous testing for safety, nutritional value and palatability. If successful, on-site production of ingredients such as Solein could reduce the mass and logistics of resupply missions and increase mission self-sufficiency.
Why it matters: Producing foodstuffs from air and recycled waste could lower launch costs, shrink storage requirements, and make longer human missions more sustainable. The pilot will clarify technical feasibility and the steps required before any routine use in space.
Note: The current program focuses on developing and validating the technology; widespread use aboard the ISS or on lunar/Martian habitats would require further testing and regulatory approval.