Space farming of vegetables: Growing crops beyond earth

Abstract

As humanity looks beyond Earth to explore and potentially colonize other planets, one critical challenge stands out was how to sustain life in space. The long-term resupply from Earth raised the cost of space mission, and dried foods for months affected the health of crews. Considering these aspects of space mission, space culture and particularly vegetable cultivation in space, has great significance. Vegetables are more responsive to environmental parameters, have short growth duration, rich in minerals and nutrients, require less space to grow and are easy to cultivate. These features make them an inevitable component of space culture. Vegetables that are ready to eat after harvest are preferred for space culture. Plant growth chambers are typically utilized to study plant behaviour and development under reduced gravity and in closed environments. It includes Oasis, ‘Veggie’ (Vegetable Production System) ‘Advanced Plant Habitat’ (APH) and so on. An irrigation and nutrient delivery system (NDS) for space missions must support all stages of plant growth while ensuring proper water, nutrient supply, and root aeration within spacecraft safety constraints. Substrate-based systems using 1-2 mm arcillite mixed with Osmocote were preferred over aeroponic or hydroponic systems. Additionally, the porous tube plant nutrient delivery system (PTPNDS), was widely used in space agriculture due to its ability to retain water, supply nutrients through capillary action, and prevent oxygen deficiency in both simulated and real microgravity conditions. The major challenge in space farming is microgravity. Reduced gravity and microgravity affect water and nutrients delivery to plants. Moreover, under microgravity, thicker boundary layers formed around plant leaves that reduce transpiration, as well as gas exchange and caused deleterious changes in pH with serious effects on cell metabolism. In the near future, space exploration will increase, and the cultivation of plants may be necessary to supplement the dietary needs of the crew members in flights. This calls for more research intervention in space culture of vegetables. There is also ample scope for our country to initiate research and development in this rather challenging yet exciting field of space culture.