The supply of astronauts on multi-year missions to Mars or a permanent moon base presents significant logistical challenges for space travel. Every kilogram of food that needs to be brought from Earth considerably increases the cost of the mission. ESA is now focusing on an unconventional solution: the HOBI-WAN pilot project (Hydrogen Oxidizing Bacteria In Weightlessness As a source of Nutrition) aims to produce proteins “out of thin air.”

This is made possible by a process called gas fermentation, which is already being commercially developed on Earth by the Finnish company Solar Foods under the product name “Solein.” Specialized microorganisms (Xanthobacter bacteria) convert carbon dioxide, hydrogen, and nitrogen into edible proteins. The result is a yellowish powder that is high in protein and is said to be neutral in taste.

On Earth, the process uses carbon dioxide from the atmosphere; in space, the astronauts’ exhaled CO₂ would be recycled. The required nitrogen is to come from a particularly unusual source: astronaut urine. Urea, the main component of urine, contains bound nitrogen that can be broken down by the microorganisms. Hydrogen would be obtained through electrolysis of water, and the resulting oxygen could simultaneously refresh the breathing air.

Technical Hurdles in Orbit

However, transferring the process to zero gravity is anything but trivial. In microgravity, liquids and gases behave completely differently than on Earth. The HOBI-WAN project is intended to investigate these problems systematically. Initially, terrestrial tests will be conducted, simulating the conditions of a space mission. Later, experiments on the International Space Station ISS could follow. Researchers are still years away from a deployable system.

“For long-term missions beyond Earth orbit, autonomy in food production is crucial,” emphasizes ESA. A closed system that recycles waste products and generates new food from them could make certain manned missions possible in the first place.

According to current plans, a Mars mission would take at least three years. Carrying conventional food in sufficient quantities would require enormous mass and volume. Even on the ISS, the crew relies on regular supply flights.

Compared to growing plants, which is also being researched, gas fermentation has a major advantage: it does not require large cultivation areas or natural light. The microorganisms work in compact bioreactors and could theoretically produce proteins around the clock.

Culinary Delights in Space?

Whether astronauts will actually find the protein powder a tasty addition remains to be seen. ESA is also researching other unconventional protein sources in parallel, including insects. Solein can be processed in a versatile way – as an ingredient in pasta, protein shakes, or as a meat substitute.

The HOBI-WAN project is part of a broader ESA strategy to prepare for manned missions into deep space. In addition to food production, the agency is working on life support systems, radiation protection, and psychological aspects of long space flights.

(mki)

Don’t miss any news – follow us on Facebook, LinkedIn or Mastodon.

This article was originally published in German. It was translated with technical assistance and editorially reviewed before publication.