A System Dynamics Model of a Hybrid Life Support System

The employment of bio-regenerative processes complemented with physical-chemical backup systems and vice versa is thought to have numerous advantages from the perspective of redundancy for the sustained human presence in space or on other planetary surfaces. These so called hybrid life support systems are a concert of many interdependencies and interacting feedback loops, which are challenging to operate in a desired range of set points. Furthermore, the complexity of such systems makes them vulnerable to perturbations. Applying system dynamics modelling to study hybrid life support systems is a promising approach. System dynamics is a methodology used to study the dynamic behaviour of complex systems and how such systems can be defended against, or made to benefit from, the shocks that fall upon them. This paper describes the development of a system dynamics model to run exploratory simulations, which can lead to new insights into the complex behaviour of hybrid life support systems. An improved understanding of the overall system behaviour also helps to develop sustainable, reliable and resilient life support architectures for future human space exploration. The developed model consists of various modules for different life support functions. The greenhouse module simulates plant cultivation. The crew module calculates the inputs and outputs of the crew, while the physical chemical systems module represents a number of life support technologies. All modules are interconnected to simulate a hybrid life support system in a future space habitat