Exploring the impact of irregular metabolic efficiencies and the space environment on the survivability of a regenerative life support system through agent-based modeling

The survivability of a regenerative life support system during long-duration missions in interstellar space was simulated using an agent-based model (ABM) of MELiSSA. In this ABM, humans, plant plots and bioreactors are modeled as virtual agents that interact with each other. The ABM approach enables the introduction of heterogeneity at the level of agent attributes, and thus allows for the study of complex interactions that cannot be observed in more traditional equation-based modeling techniques. Properties, behavior, life cycle (e.g. growth curves and susceptibility to nourishment deficits), and rules of interaction are specifically modelled for each type of agent. The behaviors are modeled according to the major chemical reactions and productivities of each MELiSSA compartment, as documented in publicly available sources. A first series of simulation experiments investigates the survivability of the system under stress conditions of two types: stochastic metabolic efficiencies and environmental stressors. The following environmental stressors were conceptually simulated: cosmic radiation reducing metabolic functionality, and particle impact causing loss of life support system elements. A second series of simulation experiments explores the impact of different policies for nutrient distribution, both under normal and aforementioned stress conditions. The research on which this paper reports is part of the E|A|S (Evolving Asteroid Starships) project by the DSTART team at Delft University of Technology. The project entails conceptual research on interstellar travel, including onboard regenerative ecosystems.