Tomatoes for lunar and Mars habitats
A symbiotic community of bacteria, tomatoes and single-celled algae, synthetic urine and a satellite that simulates the gravity of the Moon or Mars by rotating around its axis – these elements make up the German Aerospace Center (Deutsches Zentrum für Luft und- Raumfahrt; DLR) Eu:CROPIS (Euglena and Combined Regenerative Organic-Food Production in Space) mission. Two greenhouses are scheduled for launch into space in 2016. In them, a combined life-support system will utilise the waste product recycled urine to manufacture fertiliser and help grow tomatoes for a lunar and Mars habitat, also on long duration missions. This project will run for a year, after which the satellite will burn up in Earth's atmosphere.
The DLR scientists will use the cooperation between bacteria and the single-celled alga euglena gracilis to supply the plants with important nutrients. Synthetic urine will be added to the system at regular intervals and then passed through the lava plates in the trickle filter, integrated within the water circulation mechanism and home to countless microorganisms waiting hungrily for these nutrients. Initially, these bacteria break down ammonia into nitrite, and subsequently into nitrate to remove elements that are toxic for the plants and produce precisely the appropriate fertiliser to allow the tomato plants to bear fruit and produce new seeds. Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) contributes its euglena to counteract the precipitous rise in ammonia levels: euglena are insensitive to ammonia and assist to its rapid breakdown. "We exploit the properties of these organisms to convert substances into nutrients that are needed to sustain other organisms," explains the mission's Scientific Director Jens Hauslage from the DLR Institute of Aerospace Medicine.
Link to the full article: "Eu:CROPIS – Growing tomatoes in space".