MICROSCOPE Thermal Control Design and First In-Orbit Thermal Control Performance Results




Torresi, Patrizia

Journal Title

Journal ISSN

Volume Title


47th International Conference on Environmental Systems


MICROSCOPE (MICRO-Satellite à traînée Compensée pour l'Observation du Principe d'Equivalence) is a microsatellite of the CNES Myriade series which includes Demeter, Parasol, Picard, Spirale, Essaim and Elisa missions (13 other satellites). Microscope was successfully launched on 25th April 2016 from Kourou, French Guiana, on the Soyuz launcher. The orbit of Microscope is a Sun-synchronous orbit at an altitude of 710 km. The main scientific objective is testing of the Equivalence Principle (EP) with a 100 times better accuracy than realized with experiments on Earth: the MICROSCOPE space mission aims at testing the universality of free fall with an accuracy better than 10−15. The MICROSCOPE experiment requires very stringent thermal stability (in a low Earth orbit environment): the stability shall be better than 1 mK at f_EP (EP frequency) for the differential micro-accelerometers and 10 mK at f_EP for the electronics units. In addition, in order to reduce any perturbation, thermal control needs to be exclusively passive: active heaters are not permitted during the payload science operations. Moreover, the required thermal stability of the payload highly constrains the spacecraft design and the mission. The payload is uncommonly accommodated at the centre of the spacecraft, whereas MYRIADE microsatellites usually have their payload on an external wall. While using mainly recurrent Myriade platform equipment, the propulsion module is quite specific: it is defined to provide a very steady environment to the experiment and a fine control of its attitude and of its drag-free motion along the orbit. This paper presents an overview of the thermal design of Microscope and the preliminary in-orbit results. In-Orbit Thermal Performance shows that the thermal control system can successfully meet the thermal stability requirements.


Patrizia Torresi, Centre National d'Etudes Spatiales (CNES), France
ICES101: Spacecraft and Instrument Thermal Systems
The 47th International Conference on Environmental Systems was held in South Carolina, USA on 16 July 2017 through 20 July 2017.


Microscope, thermal stability, Passive thermal control