The CoRoT satellite in flight : description and performance

TL;DR

The paper describes the in-flight behavior and performance of the CoRoT space telescope, highlighting how environmental factors affect data quality and confirming that the instrument meets its specifications in various conditions.

Contribution

It provides a comprehensive in-flight performance analysis of CoRoT, detailing environmental impacts and data correction methods based on flight data since launch.

Findings

Performance specifications are met under favorable conditions.

LEO perturbations significantly affect data quality.

Straylight from Earth reflections is negligible.

Abstract

CoRoT is a space telescope dedicated to stellar seismology and the search for extrasolar planets. The mission is led by CNES in association with French laboratories and has a large international participation: the European Space Agency (ESA), Austria, Belgium and Germany contribute to the payload, and Spain and Brazil contribute to the ground segment. Development of the spacecraft, which is based on a PROTEUS low earth orbit recurrent platform, commenced in October 2000 and the satellite was launched on December 27th 2006. The instrument and platform characteristics prior to launch have been described in ESA publication (SP-1306) . In the present paper we detail the behaviour in flight, based on raw and corrected data. Five runs have been completed since January 2007. The data used here are essentially those acquired during the commissioning phase and from a long run which lasted 146 days, these enable us to give a complete overview of the instrument and platform behaviour for all environmental conditions. The ground based data processing is not described in detail, the most important method being published elsewhere. It is shown that the performance specifications are easily satisfied when the environmental conditions are favourable. Most of the perturbations, and consequently data corrections, are related to Low Earth Orbit (LEO) perturbations: high energy particles inside the South Atlantic Anomaly (SAA), eclipses and temperature variations, and line of sight fluctuations due to the attitude control system. Straylight due to the reflected light from the earth, which is controlled by the telescope and baffle design, appears to be negligible.