Microalgae on the way to space

Les-micro-algues-en-route-pour-l-espace Algorigin

Space travel, especially to the most distant planets, requires autonomy in oxygen, water and food. No outside sources can be imported into these shuttles en route! So, micro algae, so small, so powerful and so nutritious, are currently the subject of serious scientific studies with the aim of accompanying future astronauts on their journeys.

SPACE ADVENTURE, TECHNICAL CONSTRAINTS

For flights lasting a few days, it is easy to provide the necessary supplies for spacecraft occupants while maintaining sufficient storage space for waste. But, for trips lasting several months, far away and therefore without supplies, such as going to Mars, this logistical aspect becomes a real constraint, especially in terms of weight. Indeed, a human organism uses at least 5 kg of water, food and oxygen per day and produces numerous gaseous, liquid and solid wastes. The tonnage to be transported being proportional to the duration of the journey, two solutions are then available: increase the power of the launchers in order to send the tonnage necessary for life over several months or providevery concentrated nutritional resources and set up an autonomous system for recycling the waste produced by these space travelers.

THE MELISSA PROJECT, A CLOSED AND ECONOMIC ECOSYSTEM

The European Space Agency, thanks to the Melissa¹ project (Micro-Ecological Life Support Alternative), is aiming for this last solution by studying for more than 25 years the possibility of predicting The very interior of space ships a closed and self-sufficient ecosystem.

Spirulina seems to be particularly suitable for this type of mission. Indeed, micro algae have a double interest, they have the capacity to transform fatty acids and carbon dioxide (CO2) into oxygen (O2) and are particularly interesting as supplements. quality nutrients. However, many constraints, non-existent on Earth, are present in space. The absence of natural reserves (oceans, soil, atmosphere) and the presence of radiation lead to rapid evolution of micro-organisms. These autonomous systems guarantee the survival of astronauts and therefore need to be perfectly operational when they are implemented. Currently tests on Earth as well as in space are being carried out in order to find the right balance and guarantee their effectiveness.

FEEDING THE ASTRONAUTS, A “MICRO” SIZE CHALLENGE

In order to be shipped, food must meet several criteria including not making crumbs, being pasteurized to avoid contamination on board or even being tasty because the sense of taste is reduced in weightlessness. But we also ask them to be compact, light and nutritious. However, these last three criteria are difficult to meet for common foods. Indeed, for a large majority of them, the nutritional intake is sufficient for a relatively large quantity and therefore rather space-consuming. So why not supplement rations with spirulina, compact, light and very nutritious?

Read also: Algae and the vegan diet

For comparison, for an intake of about 25g of high biological value proteins , you need to consume 100g of meat compared to only 35g of spirulina. And since on average a 70kg astronaut should consume about 220g of meat, by dividing the ration by 2 and supplementing with spirulina, you would already gain more than 2kg of weight for 1 month . This may not seem like much, but when every gram is counted, it can quickly weigh heavily in the balance. When we also know that spirulina is rich in vitamins and minerals, there is no doubt that micro algae will have their place in the next space odysseys.

And if one day man really walks on Mars, it will undoubtedly be thanks to microalgae!

Read: Algae and the environment

^Sources

^{https://www.esa.int/Our_Activities/Space_Engineering_Technology/Melissa}