Modular Design of Space Expandable Capsule Based on Origami-Inspired Structures and Stretchable Mechanism

Abstract The deployable structures based on origami have been widely utilized in the design of spacecraft structures. With the advantages of foldability and stowability, origami-inspired structures can be folded into a pre-designed shape to fit into the rocket envelope. In this study, a novel configuration of the modular expandable capsule was developed based on origami-inspired structures and stretchable mechanism. The whole capsule was composed of multiple identical units with origami structures. In each unit, the geometric parameters such as width and length were quantitatively designed, and their influence on the packaging ratio of each unit was discussed. The origami creases were treated as joints in the context of motion structures. Then, Denavit and Hartenberg (D-H) method was adopted to establish kinematic relation of capsule units. Through the theory of thick origami, motion characteristics of each unit with nonzero thickness panels can be constructed. Furthermore, stretchable mechanism with hyperelastic behavior was employed to resolve issues of geometric compatibilities during the process of folding and expanding. Finally, a prototype of origami-inspired capsule unit was fabricated to examine its motion behaviors. The results demonstrated the feasibility and effectiveness of such a design for potential space missions. This work can be treated as an innovative attempt to design large-scale space architectures, which can be assembled and constructed on orbit.