High-Expansion-Ratio Deployable Space Structures for Long Duration Space Missions

Artificial gravity is a crucial technology to enable long-duration human space flight. However, a kilometer-scale rotating space structure is needed to generate artificial gravity at rotation rates that can be tolerated comfortably by crew. Constructing such a structure with current technology would require many launches and significant in-space assembly. This work presents HERDS, High-Expansion-Ratio Deployable Structures, a hierarchical expansion mechanism that can deploy a kilometer-scale structure from a single launch. HERDS leverages a hierarchical combination of a Kresling mechanism and a pop-up extending truss (PET), a novel variant of the scissor mechanism. We show that HERDS designs achieve 4-11x better beam member aspect ratios than non-hierarchical Kresling or scissor mechanisms, resulting in a stiffer deployed structure. Furthermore, HERDS designs are shown in simulation to satisfy the necessary loading and structural constraints for supporting the Lunar Gateway mission with a factor of safety greater than 1.5 using existing launch vehicles. Our modeling and analysis is validated on a 1/10 scale prototype with a 50x expansion ratio.