news AMOS delivered the first flight model of the optical derotator for the METimage instrument

Airbus Defence and Space selected AMOS to deliver critical parts of the METimage Earth Observation optical instrument for the second generation of the EUMETSAT Polar System. The METimage instrument is developed by an industrial team led by Airbus Defence and Space GmbH on behalf of the German Space Administration DLR with funds from the German Federal Ministry of Transport and Digital Infrastructure and co-funded by EUMETSAT.

METimage is a visible and infrared imaging spectro-radiometer which will be embarked on the series “A” of the METOP Second Generation weather satellites. These three polar-orbiting spacecrafts will provide detailed information on clouds, cloud cover, land surface properties, as well as oceans, ice, and land surface temperatures, contributing to future improvements to meteorological and climate forecasting.

AMOS delivered the first flight model of the optical derotator to be embarked in the instrument. The derotator is composed of a set of flat mirrors assembled on a rotating structure. The purpose of this complex opto-mechanical sub-system is to ensure a regular imaging geometry on the detectors over the full angular range realized by the scan mirror.

The allocated volume and weight of the derotator generated significant constraints on the design of the derotator, imposing to build not only the mirrors but also the structure in silicon carbide. This material is indeed very stiff and lightweighted, allowing to create robust but compact structures. It is however brittle and a careful design with an extreme care in manufacturing were required to complete the flight models.

AMOS manufactured the optical elements with the ultimate precision. The surface accuracy of those components reaching a few nanometers, while the roughness is better than 0.8 nm. This means that the “bumps” and “digs” on the surface shall be smaller than the diameter a few atoms on average!

“This delivery is a major milestone in this project. “, declared Philippe Gilson, CEO of AMOS. “Few companies in Europe can build such instrument. Furthermore, it is very gratifying to contribute to a mission which will help improve weather forecasts and our understanding of climate dynamics.”

AMOS is now working on the delivery of the subsequent flight models for Airbus.

METimage derotator under test campaign

Published on 22.12.2021
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