PRECISION FORMATION FLYING FOR THE DARWIN INTERFEROMETER

摘要

ESA's DARWIN mission is to accomplish the unprecedented challenge of finding Earth-like planets orbiting nearby stars. To tell apart the planet from its blinding 'sun', the system relies upon nulling interferometry: the light collected by six free-flying telescopes is recom-bined inside a central 'hub', in a way that the beams from the star are 'nulled', while those from the planet interfere constructively. The diameter (50 to 500m) of the free-flying interferometer is determined by the need for angular resolution. In contrast, the differences in optical pathlength between the incoming beams must be kept below 5 nm. The article provides highlights on the results of the ongoing ICC study for ESA. Decisive architecture choices are addressed first (centralised or decentralised control), leading to a reference GNC architecture. Then the control design approach relying on LQG synthesis is presented. Finally, preliminary performance results based on a simplified synthesis show the validity of the approach.