The goal of ATHENA (Advanced Telescope for High-ENergy Astrophysics) mission is to develop an X-ray telescope able to address the Cosmic Vision science theme ‘The Hot and Energetic Universe’. PIAP Space’s role in this project is TAS-PL (Thales Alenia Space Poland) supplier of MGSE for assembly, integration and testing of a Science Instrument Bench prototype. The goal of the project is to develop a prototype of a satellite structure to validate some of the technical presumptions.