Renewed interest in missions to explore other planets has created a need for new advanced heat shield systems that will protect spacecraft from the severe heating encountered during hypersonic flight through planetary atmospheres. Both reusable and ablative TPS have been developed to protect spacecraft. Typically, reusable TPS have been used for the Shuttle where the reentry conditions are relatively mild while ablative TPS materials have been used on planetary entry probes where high heating rates are generated. Additional advances in TPS design are needed to deliver large payloads to the moon and Mars, and to explore the outer planets. Flexible or deployable aeroshells offer an approach for achieving larger aeroshell surface areas for entry vehicles than otherwise attainable without deployment. Larger surface area aeroshells offer the ability to decelerate high-mass entry vehicles at relatively low ballistic coefficients. However, for an aeroshell to perform even at the low ballistic coefficients attainable with deployable aeroshells, a flexible thermal protection system (TPS) is required that is capable of surviving reasonably high heat flux and durable enough to survive the rigors of construction, handling, and deployment. Aspen Aerogels proposes to develop ablative flexible reinforced aerogels to meet this challenge.