Radiative Cooling in Outer Space: Fundamentals, Advances in Materials and Applications, and Perspectives

Abstract Effective thermal control is critical for the safe operation of spacecraft in the harsh environment of outer space. Radiative cooling (RC), an advanced passive thermal management technology, enables spontaneous heat dissipation via infrared radiation into the ultracold cosmic background. It offers an energy‐efficient solution for maintaining temperature stability without power input. While RC materials have demonstrated promising potential in space applications, a systematic review focusing specifically on their performance and adaptability in space environments remains lacking. To fill this gap, this review first clarifies the fundamental and material‐requirement differences between terrestrial and space‐based RC. Next, it focuses on the space environmental effects on RC materials and their protection strategies, including extreme temperature fluctuations, space dust deposition, vacuum ultraviolet (VUV) radiation, and atomic oxygen (AO) erosion. Finally, key challenges and future research directions are discussed to guide the development of next‐generation RC materials for integrated spacecraft thermal control. This work provides valuable insights into advancing RC technologies, with implications for improving energy efficiency, extending mission lifespans, and enhancing system reliability in future space exploration.