Mission Concept for Autonomous on-orbit Assembly o...

Self organisation is the result of a set of dynamical mechanisms whereby structures appear at a global level due to the interactions amongst lower-level components. Self assembly can be considered a sub-domain of self organisation, where lower-level components actually form structures out of themselves rather than inert elements of the environment. Observing the instances of self-organisation and self-assembly widespread in nature we can marvel at the robustness of the processes and the complexity of the structures that are produced. In this paper we draw inspiration from these processes to face the problem of the conceptual design of an assembly scheme for a large reflector in space. ESA, JAXA and NASA have identified several new mission concepts, including very large aperture telescopes and solar power collection and transmission systems, that require the construction of a large reflective surface in orbit. As long as the characteristic dimension of the reflector array is increasing the necessity of an in-situ assembly of different components by means of an automated procedure arises. Besides, the design criteria for hypothetical reflector array elements are identical to those for solar sails low mass per unit area (high assembly loading), high specular reflectance (high sail efficiency), and stowability in a tight volume. In this paper the feasibility of reflector elements doubling as solar sails for a sailing transfer up to the reflector construction site from a lower orbit and then self-assembling into a large reflector is investigated. Such a strategy potentially reduces significantly the number of launches required to place a reflector array into position. The phase of the assembly process that requires proximity operation between several components is then studied relying upon novel techniques based on swarm intelligence.