How will astronauts survive on months-long missions to the Moon or Mars in the future—without resupply from Earth? One possible answer doesn’t grow in fields, but comes from a bacterial culture that is fermented to produce a nutrient-rich protein. Together with the Finnish food tech pioneer Solar Foods, OHB System AG is launching this vision into space on behalf of the European Space Agency: In the HOBI WAN (Hydrogen Oxidizing Bacteria In Weightlessness As a source of Nutrition) project, this innovative food production method is to be tested for the first time in microgravity aboard the International Space Station (ISS). The study phase for the pilot project has now begun and is funded by ESA through the Terrae Novae Exploration Program.
Fermentation Instead of Field Work
The technology is based on a fascinating principle: the nutrient solution of a bacterial culture is supplied with gaseous hydrogen, oxygen, and CO₂ in a bioreactor. Urea serves as the nitrogen source for protein synthesis. Through fermentation, the bacteria convert these substances into “solein”—the name given to the new, protein-rich powder that requires neither farmland nor sunlight. So instead of growing lettuce, carrots, or tomatoes in soil, the protein essentially grows “out of thin air.” The test container for this will be a classic Middeck locker, the type that has been in use on the ISS in orbit for years. It will contain all the components required for the bioreactor, such as an incubator, measuring instruments, control units, and systems for taking samples.
“Since the European Columbus module became operational, OHB has been closely associated with the International Space Station. We have been developing, operating, and maintaining scientific payloads for the station for over two decades. Our deep understanding of the ISS environment, combined with our experience in life support systems and scientific experiment platforms, makes us the ideal partner to bring Solar Foods’ Solein technology into orbit, and we are very much looking forward to this collaboration,” says Jürgen Kempf, HOBI WAN project manager at OHB. However, the mission goes far beyond testing a novel protein source, according to Kempf. “We are exploring how we can sustainably support human life in space. The insights we gain here could also help address global challenges on Earth—such as resource scarcity and food security. We are proud to contribute our expertise to a project that combines space innovation with planetary sustainability.”
Phase 1: Ground-based scientific model
During the eight-month study phase, a scientific model will first be developed on the ground. The goal is to validate the fundamental processes to determine whether Solein production can also function under microgravity. The Finnish company’s bioprocess technology must be adapted into a compact, autonomous system capable of operating reliably under zero-gravity conditions. For example, special cartridges must introduce gases without any liquid leakage, and almost everyone knows what a highly explosive mixture oxygen and hydrogen can create when they come into contact. A total of three experiments are to be housed in the test box, and the astronauts will also need to take samples during the experiment’s duration. Thanks to experience from previous Biolab experiments, OHB knows which materials and components are well-suited for use in space.
“We are very pleased to be collaborating with OHB. Their expertise in evaluation and certification—particularly with regard to the necessary safety requirements—will help us develop a system that is suitable for the space environment, delivers the required data, and, above all, can be operated safely on a crewed space station,” says Arttu Luukanen, Senior Vice President of Space & Defense at Solar Foods.
Launch to the ISS scheduled
If the first phase is successful, the next step will be to develop the flight model with the goal of sending it to the ISS. The HOBI WAN project is part of a growing European commitment to so-called closed-loop systems—that is, systems that autonomously provide water, air, and food. The results are intended not only to advance space exploration but also to provide impetus for sustainable food solutions on Earth—particularly in regions with scarce resources.