ABSTRACT
Control of spacecraft with large flexible structures and very demanding astronomical specifications involves significant difficulties due to the combination of flexible modes with small damping, model uncertainty, and coupling among the inputs and outputs. This chapter provides a case study that deals with the design of a multi-input-multi-output (MIMO) Quantitative Feedback Theory (QFT) robust control strategy to simultaneously regulate the position and attitude of a spacecraft telescope with large flexible appendages. The spacecraft is part of a multiple formation flying constellation of European Space Agency (ESA) cornerstone project: the Darwin mission. The main objective of the spacecraft control system is to meet a set of astronomical requirements, which need to keep the flying telescope pointing at both the observed space target and the central hub-satellite.
