An approach was developed for making low-density, flexible ablators for a thermal protection system (TPS) from a flexible fibrous carbon substrate and a polymer resin. The material is foldable and stowable, and can be deployed in space without compromising performance. In addition, the material can be stowed in space for very long periods of time (years) without compromising deployability or performance. These flexible ablators offer an alternative to rigid TPS materials, thereby reducing design complexity and cost. On charring, the flexible ablative TPS retains its flexibility. After charring, the TPS has comparable flexibility and mechanical properties to the virgin material.
Compositionally, this material is similar to heritage low-density rigid carbon phenolics. Advantages of this system include having a high strain to failure and a low thermal conductivity compared to the heritage systems of comparable composition. The flexible carbon substrate has a density of less than 0.2 g/cm3; however, a range of materials of different densities have been demonstrated for this system. Examples of thermosetting polymers that have been demonstrated in this approach include, but are not limited to, phenolic and polyimide.