Minimum angular-impulse control for ISAT

Characterization and implementation of efficient rotational motions of flexible spacecraft have been of research interest for more than twenty years. In the present study we consider rest-to-rest pointing maneuvers for a very large spacecraft, so that limits on available angular momentum are paramount. A formal system of differential equations is developed based on a model that includes a rigid central hub and Euler-Bernoulli appendages. The model is recast in an appropriate state-space and standard functional analysis methods are used to prove well-posedness and to establish a framework for numerical approximation. Several variants of minimum-angular moment problems are studied; ultimately we focus on a low-dimensional control parameterization based on a family of versine functions and on quasi-static structural response. Results are characterized in terms of simple formulae and sensitivity with respect to problem data is presented.