Scientists at the University of Stuttgart have designed an experimental photobioreactor that can convert algae into oxygen and food. It’s now being tested at the International Space Station (ISS).

Scientists in Stuttgart develop PBR for space

When astronauts set off on long-range missions into space, they need to be assured of an adequate supply of food and oxygen. To minimise the amount of resources that need to be taken, researchers are working on systems that can recycle water and air as efficiently as possible - and even produce plant-based food in space.

Together with the German Aerospace Centre, a team of researchers at a university in Stuttgart have designed a photobioreactor (PBR), capable of providing astronauts with a long-term supply of food and oxygen. Now, a prototype built by Airbus has been taken into space and is being tested over a period of 180 days at the ISS.

How does the PBR work?

The idea is that the PBR uses an algae known as Chlorella vulgaris to absorb concentrated carbon dioxide from the ISS’s atmosphere. Scientists can then take the absorbed CO2 and convert it into oxygen via a chemical reaction. At the same time, the plant also converts the carbon dioxide via photosynthesis into an edible biomass.

The edible biomass produced by Chlorella vulgaris is naturally high in protein, unsaturated fatty acids and various vitamins. It is already widely used in the production of food, health supplements and aquaculture. If the experiment is successful, researchers estimate that the algae could provide as much as 30 percent of astronaut nutrition on long-haul flights.

Algae could be the key to sustainable food on earth

After the experiment has concluded, the researchers will evaluate the PBR’s effectiveness and stability. This will include bringing several algae samples back to earth for evaluation. Initial tests have already shown that the plant should be resilient to extraterrestrial conditions, but this is the first time anyone has attempted to cultivate it on a large scale in space.

The project’s leaders hope that the PBR technology will not only help astronauts, but might also provide a way to improve the sustainability of food production on earth. Conversely, space developments can sometimes provide us with techniques for preserving our environment back at home. But first, we’ll have to see how the PBR performs in its first major test.