Definition phase activities for ESA's Cosmic Vision mission PLATO

Abstract

PLATO - PLAnetary Transits and Oscillations of stars - is a Cosmic Vision 2015-2025 M-class mission candidate of ESA's future Science and Robotic Exploration programme. The scientific goals are to detect exoplanetary transits and to characterize the parent stars using astero-seismology. This is achieved through high-accuracy, high time-resolution photometry in the visible waveband. Assessment studies were carried out for all M-class missions during 2008-2009 in order to design a basic spacecraft configuration and identify critical areas. Following the down-selection in the beginning of 2010, PLATO will enter into the Definition Phase, in which the spacecraft design will be consolidated and optimized. The proposed payload will use a multi-aperture approach in which the combined observations of 34 telescopes with individual pupil sizes of ~120 mm will produce highly accurate light curves of the target stars. Since the orbits of the exoplanets should preferably be in or close to their habitable zone, an observation period of several years per sky field is required to detect repeated transits of the exoplanets around the parent stars. This requires a stable spacecraft with a high pointing accuracy and a benign operating environment. It is foreseen to launch PLATO using a Soyuz 2-1b via a direct insertion into a large amplitude orbit around Sun-Earth L2. This paper will give an overview of the PLATO mission and the planned activities during the Definition Phase.