This study investigates the use of the ACT-R (Adaptive Control of Thought-Rational) cognitive architecture to model decision-making processes in dynamic and unpredictable space mission scenarios. The primary objective is to enhance our understanding of the cognitive mechanisms that underlie astronauts’ decision-making, with the goal of improving training programs and support systems for space missions. Space missions often involve complex, high-stakes decisions that must be made in rapidly changing environments, making robust cognitive models essential for preparing astronauts to handle such challenges effectively. The methodology involved designing specific decision-making tasks that simulate space mission conditions and integrating these tasks into the ACT-R framework. Data was collected through a combination of behavioral experiments and computational modeling. Results indicate that the ACT-R model successfully replicates key aspects of human decision-making patterns observed in the experimental tasks. The model demonstrates high fidelity in simulating the decision-making process, including the adaptation to new information and feedback, which is critical in dynamic space environments. Notably, the model’s performance highlights areas where cognitive strategies differ among participants, providing insights into individual differences in decision-making under stress. The discussion addresses the implications of these findings for astronaut training and mission planning. The ACT-R model’s ability to predict and simulate human decision-making offers a valuable tool for developing targeted training programs that enhance cognitive flexibility and resilience. Furthermore, the model’s insights can inform the design of support systems that assist astronauts in making optimal decisions during missions.