Bioinspired Structured Passive Radiative Cooler with Enhanced Reflectivity and Emissivity for Spacecraft Thermal Management

ABSTRACT Radiative cooling materials represent a highly promising strategy to the critical challenge of aerospace overheating systems, an issue that conventional convection‐based methods cannot resolve. However, their widespread practical application is severely constrained by insufficient cooling efficiency and inadequate environmental stability. Herein, inspired by the dual optical manipulation capabilities of butterfly wings, a metal‑based long‐lasting utility passive radiative cooler (PRC) with enhanced radiative cooling property is successfully designed and fabricated. Optically, it integrates the Mie scattering effect from Pieris and the optical interference effect from Sara into an Al‐based architecture, realizing high reflectivity (85%) in visible spectra and high emissivity (99%) in mid infrared. Under ground‐level solar illumination, PRC achieves a temperature reduction of 13.5°C and a 50% enhancement in cooling efficiency. As for vacuum conditions with lighting, the PRC achieves a temperature reduction of 9.1°C, corresponding to a cooling efficiency of 10.1%. Remarkably, after various mechanical (sand erosion) and chemical stability (UV and atomic oxygen exposure) tests, it can approach initial cooling performance, demonstrating outstanding operational stability. This bioinspired Al‐based PRC offers an efficient thermal management strategy for high‐power spaceborne equipment and presents a novel approach to spacecraft heat dissipation.