Ultralight and Ablation-Resistant Shape-Memory Ceramizable Polymer Aerogel for Self-Adaptive Thermal Protection

Deployable thermal protection systems (DTPS) for deep-space exploration require materials that integrate lightweight design, high deformability, and extreme temperature resistance. However, existing shape memory polymers (SMPs) suffer from limited thermal stability, while shape memory ceramics (SMCs) lack rapid programmability and efficient deployment capability. To overcome these limitations, a shape-memory ceramizable polymer aerogel (SMCPA) is developed capable of sequential self-adaptive thermo-responsive behavior, enabling the integration of structural deployment and thermal protection within a single material system. Upon exposure to high temperatures, SMCPA first undergoes rapid shape recovery to increase the projected area, followed by in situ ceramization at elevated temperatures to form a continuous ablation-resistant ceramic layer. The resultant SMCPA combines ultralow density (0.12 ± 0.02 g cm^-3), outstanding shape-memory performance (shape fixation ratio of 97.0 ± 0.5% and shape recovery ratio of 94.2 ± 0.6%), with remarkable ablation resistance (mass ablation rate of 0.012 ± 0.003 g s^-1 under 1.5 MW m^-2 heat flux), outperforming conventional SMPs and SMCs in its ability to simultaneously provide programmable shape change and high-temperature stability. This study demonstrates that SMCPA successfully reconciles the conflict between lightweight deployable structures and high-temperature thermal protection, offering a promising material solution for next-generation DTPS in deep-space missions.