## 13 Conclusions  
In conclusion, the exploration of risk, sustainability, and supply chain in space missions is of paramount importance as we continue to venture into the vast unknown. This topic necessitates a comprehensive understanding of the potential risks involved in space exploration, while concurrently integrating sustainable practices to ensure the long-term viability of our endeavors. The review, multi-objective conceptual optimization model, and practical approach discussed in this paper shed light on the significance of addressing risk, sustainability, and supply chain for space missions and provide valuable insights into how we can approach these challenges. The review presented a thorough examination of the various types of risks encountered in space missions. Technical risks, human risks, launch and reentry risks, space environment risks, mission design, and planning risks, budgetary and schedule risks, as well as political and international risks, were all identified and discussed. This comprehensive overview serves as a reminder that space exploration is a complex and high-stakes endeavor, requiring meticulous planning, robust engineering practices, and continuous risk assessment. Moreover, the review highlighted the need to incorporate sustainability principles into space missions. This includes mitigating negative environmental impacts, optimizing resource utilization, considering ethical considerations, engaging in long-term planning, fostering international cooperation, and promoting public outreach and education. By aligning space exploration with sustainable practices [111], we can maximize the benefits while minimizing the detrimental effects on the space environment and future missions. The introduction of a multi-criteria optimization model further strengthens the approach to risk, sustainability, and supply chain in space missions. This model provides a systematic framework for evaluating and selecting mission strategies that balance multi-objective, such as environmental impact, resource utilization, mission cost, and societal benefits. By considering the trade-offs between different criteria, the model enables decision-makers to identify sub-optimal solutions that align with sustainability objectives while effectively managing risks, and optimizing supply chain efficiency. The practical approach presented in this paper exemplified the practical application of the multi-criteria optimization conceptual model. Through the practical approach, we witnessed how the model could guide the design of a space mission, taking into account various risk factors, sustainability considerations, and supply chain planning. The practical approach underscored the importance of optimizing resource utilization, reducing environmental impact, and incorporating ethical practices in the decision-making process. The main limitations of space mission risk, sustainability, and supply chain multi-objective optimization models are: data availability, complexity and uncertainty, trade-offs and conflicting objectives, dynamic nature of space missions. Recommendations for further studies on space mission risk, sustainability, and supply chain multi-objective optimization models would include: increased data collecting, advanced modeling methodologies, multi-objective decision-making frameworks, integration of sustainability and risk, implementation of advanced supply chain optimization models. Overall, the conclusions drawn from this exploration emphasize the crucial role of addressing risk, sustainability, and supply chain [112] in space missions. By understand ing and mitigating the diverse risks associated with space exploration, we can ensure the safety of astronauts and the success of the mission. Simultaneously, integrating sustainability principles into space missions allows us to preserve the integrity of the space environment, make efficient use of resources, foster international cooperation, and inspire future generations.