MELiSSA's aim is to ideally create an artificially closed ecosystem to autonomously recycle the wastes to oxygen, water and food with only the input of energy to drive the process.

The nitrifying compartment's main function is to cycle NH4+ produced from waste to nitrates, which is the most favourable source of nitrogen for higher plants as well as Arthrospira platensis.

Physiochemical processes such as the Sabatier reaction would result in high efficiencies, but a large amount of energy is required in terms of temperature and pressure.

Higher plants (wheat, rice, salad ingredients) would be utilised to produce food for the crew members.

However, one key difference is the targeted objective to recycle near 100% of wastes (limiting feed stock), essentially operating MELiSSA in a closed loop.

The current MELiSSA Pilot Plant is located at Universitat Autònoma de Barcelona and was inaugurated in 2009.

The final goal of the operation of the Pilot Plant is to demonstrate, evaluate and improve the feasibility of the MELiSSA loop concept on ground conditions, in order to guide the future developments towards a regenerative life support system for space applications.