EST has been formally proposed to the EU institutions by Spain and is scientifically driven by the European Association for Solar Telescopes (EAST). EAST brings together 26 European research institutions across 18 countries. This association promotes the sustainable development of EST as a pan-European research infrastructure and supports its coordinated implementation. EST will be built in La Palma observatory in a location very close to the 1-metre Swedish Solar Telescope. This location is worldwide recognised for its excellent atmospheric conditions and has led to the best solar images ever obtained, especially in blue wavelengths, where the effects of the Earth’s atmospheric turbulence is most severe. Throughout the preparatory phase of EST, significant efforts were devoted to establishing a project office with extensive design expertise to ensure the incorporation of the latest technologies, to advance the preliminary design of the EST and to optimise the telescope construction process. The project is currently at its interim phase working towards construction phase. On 25 July 2023, the European Solar Telescope Canarian Foundation (EST-FC) was created as interim legal figure for EST to manage and steer the project during this intermediate phase. By mid 2024, the EST-FC is composed by ten research institutions from eight European countries. The EST Foundation will advance the project towards subsequent phases and milestones, in particular the creation of the EST ERIC. The preliminary design review of all subsytems of the telescope by external reviewers is scheduled to be finished in early 2025. In parallel, contacts with funding agencies are taking place for the consolidation of the national contributions to the budget and for the creation of the EST ERIC to manage the construction and operation of EST. A Telescope Operation and Science Center (TOSC), located at sea level in the Canaries, and a Science Data Center, in mainland Europe, will exist to steer the operation of EST and provide data storage and access to the solar physics community.

EST is expected to have first light in the early 2030’s and will operate in two operational modes: a standard PI and a service (queue) mode. Initially, both modes will be run in parallel. Following previous experiences, it is to be expected that the service mode will be the most preferred option few years after operation. Reduction pipelines will be produced by the project and databases with science-ready data will be stored at convenient places in Europe. A Telescope Operation and Science Centre (TOSC) located at sea-level in the Canaries and a Science Data Centre (SDC) in mainland Europe will centralise the development of analysis tools and gather researchers for joint discussions. Virtual Observatory tools will be developed for a comfortable data searching and handling, as well as for merging them with data from other ground-based or space facilities. Through EOSC capabilities, world access and compatibility will be guaranteed. All these tools will change deeply the way data produced by a solar ground-based telescope are analysed and merged with those from other facilities. EST is working on these developments using present solar telescopes/instruments as test-beds that demonstrate their feasibility. Within the PF7 and H2020 SOLARNET projects, dedicated pipelines for already operating instruments have been developed. Databases that contain science-ready data for some imaging and spectropolarimetric instruments have been created. Standard formats have been defined considering the peculiarities of the different telescopes and instruments, Virtual Observatory tools have been produced with a powerful searching engine. Dedicated efforts have taken place since 2019 within the European Science Cluster of Astronomy & Particle Physics ESFRI Research Infrastructures (ESCAPE) project to accommodate the data formats to a more universal character and ensure compatibility with data from other fields (especially, night-time astronomy and particle physics) and use the powerfulness of the EOSC. The work continues under a new Open Collaboration Agreement signed by the nine core ESCAPE RIs including EST.