Design of Multifunctional Hierarchical Space Structures

We describe a system for the design of space structures with tunable structural properties based on the discrete assembly of modular lattice elements. These lattice elements can be constructed into larger beam-like elements, which can then be assembled into large scale truss structures. These discrete lattice elements are reversibly assembled with mechanical fasteners, which allows them to be arbitrarily reconfigured into various application-specific designs. In order to assess the validity of this approach, we design two space structures with similar geometry but widely different structural requirements: an aerobrake, driven by strength requirements, and a precision segmented reflector, driven by stiffness and accuracy requirements. We will show agreement between simplified numerical models based on hierarchical assembly and analytical solutions. We will also present an assessment of the error budget resulting from the assembly of discrete structures. Lastly, we will address launch vehicle packing efficiency issues for transporting these structures to lower earth orbit.