9505450 MADDOCKS It is proposed to investigate recent progress in advanced theoretical dynamics within the context of the practical mechanics problems that arise in the determination and control of the attitude dynamics of artificial satellites. The project will be carried out in collaboration with Computer Sciences Corporation (CSC). The underlying motivation is that a postdoctoral associate could facilitate and exploit a two-way transfer of technology in which the modern analytical and numerical expertise that is available in the University, is tested in the light of the expertise available at CSC, namely an extensive knowledged of traditional mechanics approaches, and of practical questions that arise in flying satellites. The project will comprise case studies of specific operational satellites and comparison with actual flight data. The mathematical techniques that will be considered include applications of i) the non- canonical Hamiltonian formulation of Arnol'd to predict so-called gravity-gradient and other perturbation effects on the attitude dynamics of satellites, ii) modern Hamiltonian formulations of rod models to describe the dynamics of antennas and booms, and iii) applications of symplectic and energy-momentum integrator in high accuracy numerical simulations. The associated physical effects to be investigated will include i) coupling between attitude and orbit dynamics due to finite satellite size, and internal and external damping, ii) spin-up dynamics and instability resonances, and especially iii) effects of flexibility of satellites. The final objective is improved understanding of the attitude dynamics of satellites that will lead to robust, efficient and accurate numerical simulations.
