Pin‐Hui LanChing‐Wen HwangTai‐Chi ChenTzu‐Wei WangHSUEN-LI CHENDehui Wan2024-09-302024-09-302024-09-021616301Xhttps://www.scopus.com/record/display.uri?eid=2-s2.0-85202836638&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/721622Solar-induced thermal challenges in buildings, cold chain logistics, and spacecrafts may be overcome by integrating passive radiative cooling (PRC) with aerogels having thermal insulation (TI). Herein, a universal radiative cooling silica aerogel (UCSA) is prepared through the simple regeneration and freeze-drying of commercial quartz fiber membranes. The optically engineered UCSA with a hybrid structure (silica nanofibers/microbeads) achieves remarkable solar reflectance (RS.E. = 98.1%) and atmospheric transparency window emittance (εATW = 92.1%) under Earth conditions, with a theoretical daytime cooling power of 103.3 W m−2. In the harsh space environment, it exhibits ultrahigh average solar reflectance (RS.E. = 99.1%) and broadband mid-infrared emittance (εMIR = 90%), achieving a cooling power of 354.1 W m−2. Compared to single-functional approaches, UCSA synergistically integrates the PRC and TI performance for excellent thermal management capability. Moreover, this ceramic aerogel can resist temperatures up to 830 °C, safeguarding building occupants and spacecraft electronics. Furthermore, UCSA passes environmental aging and thermal vacuum outgassing tests for long-term viability both on Earth and in space. Finally, a USCA-covered box achieves an average sub-ambient cooling of 18.6 °C when exposed to sunlight. In summary, UCSA opens a path for energy-efficient and sustainable cooling strategy with universal applications.trueceramic nanofibrous aerogelhierarchical structurepassive radiative coolingthermal insulationthermal management[SDGs]SDG7journal article10.1002/adfm.2024102852-s2.0-85202836638