A series of polyimide aerogels with intrinsically atomic-oxygen-resistant features have been synthesized. For this purpose, 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) was copolymerized with 2,2'-dimethylbenzidine (DMBZ) and a polyhedral oligomeric silsesquioxane (POSS)-containing aromatic diamine, N-[(heptaisobutylPOSS)propyl]-3,5-diaminobenzamide (DA-POSS), with octa(aminophenyl)silsesquioxane (OAPS) as the crosslinker via sol-gel procedures followed by supercritical carbon dioxide (scCO(2)) drying treatments.