Low Earth Orbit (LEO) is characterized by severe environmental conditions: including extreme temperatures, large thermal cycling, radiations (ultraviolet (UV), charged particles, and x-ray), atomic oxygen (ATOX) and micrometeoroids and debris.

Exposure to these conditions can degrade materials and modify their properties...Those damages are likely to reduce spacecraft performance and durability.

To increase the knowledge of LEO environment and materials ageing, CNES has developed an European experiment outside the International Space Station for materials space research: Euro Material Ageing (EMA).

EMA is about to be launched on August 2024. Assembly, integration and testing have been performed. 141 materials samples and 5 types of environmental detectors will be exposed on ram direction, offering unrestricted view to space for 12 to 18 months. Materials samples are shared between CNES and ESA.

This poster present an update of the materials samples and environmental detectors exposed, with regard to the scientific objectives.

 Detectors will allow to acquire data on ISS environment : ATOX fluence and reflection with Resistack sensors, radiation level with passive optical fibres, contamination with a quartz cristal microbalance and micrometeoroides and debris with aerogels collectors.

 78 materials samples have been selected by CNES from internal research programmes and JAXA cooperation. Different types of materials have been chosen such as thermoplastics, silicones, structural composites, adhesives, optical coatings, coatings, thin films used on multi-layer insulation, adhesive tapes and contaminated samples in order to:

- Verify their behavior under LEO environment especially UV radiation and ATOX by acquiring their erosion rate, morphology, functional properties

- Compare data with on-ground ATOX results and former data of other flight experiments (MEDET, MISSE)

- Complete environmental data (ATOX fluence, contamination) by using reference materials.

 Acknowledgments: With thanks to Agnieszka Suliga from ESA/ESTEC, Sophie Duzellier and David Leveque from ONERA, Riyo Yamanaka from JAXA and Nicolas Balcon from CNES.