A Meteoroid Impact Recovery Control System for the LISA Gravitational Wave Observatory

LISA is a space-based gravitational wave detector, confirmed by ESA to be the third large class mission of the Cosmic Vision program. This kind of detection requires extremely high accuracy from laser--based sensor measurements; therefore impacts with meteoroids constitute a real threat to the mission, causing a waste of time and resources. In this work, this problem is addressed by comparing different possible recovery control systems. The recovery control system is composed by a set of controllers, each of which solves a specific recovery task. These tasks are the outcome of a preliminary data analysis of the impact data provided by ESA. In this data analysis a Spacecraft of the LISA system is modeled as a state machine and each impact-induced state transition is considered. Two main PID control recovery systems are selected, that make use of different sensor configurations: the first one requires the Constellation Acquisition Sensor, whereas the other can function without, but requires a model of the solar pressure disturbance. Finally, a set of complete impact simulations is performed in order to validate both recovery control systems.