MELiSSA is developing regenerative Life Support technologies for long-term Space missions. The MELiSSA loop is conceived as several compartments, each one performing a specific function, providing all together the basic functions in life support: food production, atmosphere regeneration, water recovery and waste treatment. The MELiSSA Pilot Plant is a facility designed for the terrestrial demonstration of this concept, hosting laboratory rats as a crew mimicking the respiration of humans, working at terrestrial conditions in industry standards and long-term experiments. Today, the work at the Pilot Plant is focused on the connection of compartments in continuous and controlled operation, in several consecutive steps, targeting to the completion of the loop. Current activities are focused on the integration of four compartments: Compartment 3 (nitrifying packed-bed bioreactor based on the co-culture of immobilized Nitrosomonas winogradsky and Nitrobacter europaea), Compartment 4a (an air-lift photobioreactor for the culture of the edible cyanobacteria Limnospira indica with concomitant oxygen production), Compartment 4b (a 5 m2 hydroponic culture plant chamber working with lettuce as plant model, producing O2 and edible material) and Compartment 5 (an animal isolator with rats as mock-up crew). The output from several continuous operation and long-term integration experiments under controlled conditions will be reported. The system showed high robustness and reliability over long operation periods (several months). The performance of the system has been analyzed both in steady-state and dynamics conditions, with extensive on-line instrumentation for the main variables, under different experimental. The transition of the system to the use of human urine is also in progress. Overall, the MELiSSA Pilot Plant has consolidated its program over the last years and is producing a collection of data demonstrating the capabilities of MELiSSA as a regenerative life support system. Future steps in the evolution of this facility will also be presented.
Godia et al. (Sun,) studied this question.