ET-COMPASS (Contribution to Early Implementation of the Einstein Telescope Project), coordinated by INFN, will build on the work carried out during the ET Preparatory Phase (ET-PP), a Horizon Europe INFRA-DEV project coordinated by the Institut de Física d’Altes Energies and led by Mario Martínez. ET-PP was launched in 2022 to address the scientific, technical, governance and organisational foundations required for the future construction and operation of the Einstein Telescope.

The Einstein Telescope is a planned underground observatory designed to detect gravitational waves with a sensitivity far beyond current facilities such as Advanced LIGO and Virgo. It aims to open a new era of gravitational-wave astronomy, enabling observations of black holes, neutron stars and cosmological phenomena across much larger regions of the Universe.

Through ET-PP, IFAE has played a central role in coordinating the European effort preparing the infrastructure, including governance models, technical design studies, site-selection preparation and long-term strategic planning for the observatory.

The newly approved project will support the next stage of the Einstein Telescope initiative, helping consolidate the organisational and technical framework needed for the transition from preparatory activities towards implementation and construction. IFAE will continue contributing as a partner in this new phase of the project.