Space Rigidizable, Deployable Ultra-Lightweight Microcellular CHEM Foams

Space rigidizable and deployable structures with ultra-lightweight, high rigidity, and space durability are desirable to improve the reliability and affordability of space structures. Some of the components currently in use like shelters or space stations use double-walled thick films with high internal pressure. All these hollow components are often vulnerable in space because debris and meteorites can strike them. They will lose their functions if hit and damaged by foreign objects. We propose to fill the cavities of these hollow components with an ultra-lightweight cold hibernated elastic memory (CHEM) or a shape memory polymer (SMP) foam that can rigidize the space structure in space so that it can maintain its functions even when struck by debris. In our phase I research, we have successfully processed ultra-lightweight microcellular CHEM foams using an environmentally friendly technique. These microcellular CHEM foams have much higher mechanical properties than those processed by the conventional techniques. We have also performed tests and proved that the microcellular CHEM foams did recover their original shapes after compaction and stowage. This capability allowed them to be packed into a very small volume, recover their shapes and be rigidized in space, thereby considerably reducing the launching cost yet providing high rigidity for space structures. The objectives proposed in the Phase I work plan have been accomplished. In this Phase II research we will scale-up the processing of the microcellular CHEM foams, further reduce their density, and optimize their mechanical properties as well as processing conditions.