The Euclid Spacecraft

摘要

Euclid is the second medium class mission of the European Space Agency in the frame of Cosmic Vision 2015-2025 program. It is a cosmology mission whose prime objective is to study the nature of the dark matter and dark energy and the geometry of the universe with unprecedented accuracy. The spacecraft will be launched in the first half of 2022 by a Soyuz launcher, to perform a six-year survey of the extragalactic sky from a large-amplitude orbit around Lagrange point L2 of the Sun-Earth system. The Euclid Spacecraft is composed of a Service Module (SVM) and a Payload Module (PLM). The PLM includes the telescope, the baffling system, the optical bench supporting the instrument detectors and front ends; the SVM comprises the platform with its subsystems, the instrument warm electronics and the Sunshield protecting the PLM from solar radiation and supporting the photovoltaic assembly. The instruments are the Visible Imager (VIS) and the Near-Infrared Spectro-Photometer (NISP), both covering a large common field-of-view enabling to survey 36% of the entire sky. The two scientific instruments are provided by the Euclid Consortium, with NISP team led by the Centre National d'Etudes Spatiales and the Laboratoire d'Astrophysique de Marseille and the VIS team led by University College London, Mullard Space Science Laboratory. Following mission approval in 2012, the Euclid spacecraft has started the implementation phase in 2013 with Thales Alenia Space as prime contractor and leading a large industrial team. The System and Mission level Preliminary Design Reviews were successfully completed in 2015. The mission phase C/D is now in progress, the Avionic Model activities on both SVM and PLM have started. The System Critical Design Review (CDR) was held earlier this year and the Mission CDR will be held in October 2018. This paper outlines the spacecraft design, providing a description of the major design drivers and resulting configuration, with a view on the current project st