Improvement of molecular adhesion for spatial applications at Thales SESO over the past 20 years

Abstract

Molecular adhesion is a well-known process used on terrestrial optics and other fields. This process consists in joining two surfaces without the use of any adhesive or additional material. Molecular adhesion is a high-precision production process, and assemblies obtained present a dimensional and thermal stability due to the absence of mechanical part or glue.For over the past 20 years, Thales SESO developed its own process of molecular adhesion. For example among others, it has been applied on the manufacturing of Fabry-Perot interferometers. Such as fused silica Fabry-Perot for ALADIN program in the frame of AEOLUS mission (launched in August 2018) or fused silica/Zerodur® Fabry-Perot for ATLID program. Both interferometer have cavities under vacuum. On the ATLID Fabry-Perot the sealing is also made using molecular adhesion. Back then, the molecular adhesion admissible mechanical strength was 1 MPa.Then, Thales SESO improved its molecular adhesion process -through lots of collaborations with CNES and other partners -in order to be able to integrate more complex designs and increase the mechanical resistance. Today the molecular adhesion admissible mechanical strength has been multiplied by a factor five.Here after, you find an overview of the Thales SESO realizations starting from Fabry-Perot first results to the latest results on corner cubes performances as well as the future of molecular adhesion for space applications imagined by Thales SESO.