Design and fabrication of lightweight thin-shell structures using shape memory polymer composites for lunar habitat systems

The increasing demand for lightweight, rigid, and deployable structures in space exploration has driven the development of advanced materials for lunar and orbital habitats. This study presents the design, fabrication, and validation of modular thin-shell components based on shape memory polymer composites (SMPCs) for deployable rigid habitats. Moreover, the durability in unexplored, harsh environmental conditions and the lower weight are the governing factors for these materials. In this context, well-developed and durable shape memory polymer-based composites (SMPCs) are ideal for these habitats due to their potential to create lightweight, thin-shell structures and their proven ability to revert to their original shape when stimulated by external factors, such as heat and light. Furthermore, this enables the manufacture of SMPC habitat components on Earth, allowing for reduced storage space in payloads, and facilitates the recovery and rebuilding of habitats after transportation. During this study Bisphenol-A cyanate ester based shape memory polymer was synthesised and reinforced with glass fibres and graphene nanoplatelets to achieve quasi-isotropic properties and enhanced thermal stability. Using vacuum-assisted resin infusion, hemispherical thin-shell modules (1 mm thickness) were manufactured and programmed into compact configurations for efficient payload storage. Experimental evaluation demonstrated excellent shape recovery (>95%) and adhesive joint strength, while distributed optical fibre sensing enabled precise strain mapping during programming and recovery. Finite element analysis validated the structural integrity of the assembled dome under internal pressures up to 2 atm, confirming its suitability for lunar habitat applications. Furthermore, this work can be considered one of the pioneering works to use space grade SMPCs in future lunar habitats. The proposed SMPC-based architecture offers a promising solution for lightweight, reconfigurable structures in future space missions, combining deployability, mechanical robustness, and thermal resilience.