The manufacturing and AIV plan for the Extremely Large Telescope Prefocal Stations

Abstract

The Prefocal Stations (PFS-A and PFS-B) of the Extremely Large Telescope (ELT) are the last component in the telescope’s light path, right before the light is delivered to the science instruments at the telescope focus. Following the Final Design Review passed in 2020 the efforts were focused on the preparation of the manufacturing documentation and on launching the manufacturing of the Prefocal Stations. The fabrication of the equipment was divided into seven main manufacturing lots based on the nature of the parts with the main aim of minimizing the project risk and optimize the schedule. The ESO's approval of each manufacturing documentation package was obtained by means of individual Manufacturing Readiness Reviews (MRR). The manufacturing of the parts and procurement of the long lead time COTS was launched in 2021 and is coming to an end. The Assembly, Integration and Verification (AIV) activities begin with the end of the manufacturing. The AIV strategy follows the well-established “V-model” methodology. The initial phases are focused on subsystem level and progressively evolves until the work is concluded with the fully assembled, integrated and verified Prefocal Stations in the ELT (Chile). Throughout this process, the fully integrated Prefocal Stations will be completely tested in the factory acceptance test (FAT) campaign in Europe. This paper summarizes the manufacturing status and describes the way Prefocal Stations AIV is planned to be carried out.