Aerogels are lightweight solids with extremely small pores, high internal surface areas, low dielectric properties, low thermal conductivity and porosities up to 98 %. Because of their many interesting properties, aerogels have been evaluated for applications, including thermal insulation, catalyst supports, sensor platforms, low dielectric substrates and acoustic materials. The most well-studied silica aerogels are exceedingly fragile; hence their use is very limited. Recently, we have developed a family of polyimide aerogels. These have mechanical properties much improved over silica aerogels while they maintain the beneficial properties. In addition, the polyimide aerogels can be fabricated into both stiff structures and thin films which are flexible and foldable. Aerospace applications of the polyimide aerogels will be presented, including use as insulation for inflatable decelerators for entry, descent and landing operations, and as low dielectric substrates for lightweight antennas. In addition, aerogels made using other polymers will also be discussed.