Manned missions to the Red Planet1 are on the agenda of many space agencies. The challenge is how to ensure the survival of astronauts in a hostile environment, where the air is unbreathable and nothing can grow. On this type of long-term space mission, the constraints and complexities are far greater than those of a mission to the Moon, such that, given the limited capacity of current launchers, it will be impossible to bring all the essential supplies from Earth2. So how and what will the astronauts eat?
The MELiSSA project
Scientists are convinced that human beings will walk on Martian soil3. The question is when. Johann-Dietrich Wörner, Head of the European Space Agency (ESA), doubts it will happen before 20504. The September 2015 announcement of the discovery of salt water on Mars revived interest in the question of life on the Red Planet5. Having researched water (with its Follow the Water programme), NASA is now focusing its exploration programmes on investigating the presence of life on Mars (Seek Signs of Life)6. The ESA programme also includes a series of space missions aimed at studying our solar system, and planet Mars in particular. Its objective is to participate in the preparation of a manned mission to Mars in the 2030s.
Since 1989, the ESA has been working on the MELiSSA project (Micro-Ecological Life Support System Alternative), a regenerative life support system that works in a closed circuit. It is an extremely complex project, aiming to create an artificial ecosystem that controls the various interactions between the organisms it comprises: humans, plants and bacteria. Hundreds of scientists are involved in the project. Once it is finalised, MELiSSA will enable the production of oxygen, water and food for astronauts, while recycling the carbon dioxide and waste produced by the crew.
This microsystem is meant to function independently. Plants will be the key component, supplying astronauts with both oxygen and food. A specific number of plants were selected, primarily on the basis of agricultural (ease of cultivation, yield), technological and nutritional criteria, for hydroponic cultivation on Mars7. The plants chosen for the MELiSSA project include soya, durum wheat, soft wheat, potatoes, onions, lettuce, cabbage, tomatoes and spinach. Then, the different stages of food processes were analysed to theoretically determine possible nutritional loss. The Institut Paul Lambin in Brussels (Belgium), collaborated with chefs to develop dishes with high nutrient density and sensory acceptability, using only ingredients produced by the MELiSSA system. They developed and tested a four-week menu which fully met astronauts’ nutritional needs during long-term missions.