Electrochemical carbon dioxide (CO₂) reduction (ECO2R) is an increasingly valuable technology that converts CO₂ into useful chemicals using various catalyst materials. This review underlines the advantages of ECO2R electrolyzers that use low-temperature electrolysis (25–80 °C) over other high-temperature electrolysis methods, particularly for applications in outer space. The potential of this technology for Mars missions is particularly intriguing, opening up new possibilities for in-situ resource utilization (ISRU) processes in upcoming space missions. This review also explores technology’s commercial potential and the importance of utilizing gas diffusion electrodes (GDEs) to enhance the ECO2R process. ECO2R has the potential to transform outer-space activities and space exploration by significantly reducing the use of Earth’s resources. It offers a sustainable alternative for continuous fuel and chemical production by utilizing gaseous CO₂, thereby reducing its carbon footprint on Earth, and presents a promising process for outer-space applications.