Making spatio-temporal data spaces FDO-ready - concept and implementation for interoperable STAC catalogues

Data spaces provide structured environments that enable integration, management and sharing of heterogeneous datasets across disciplines and institutions. This approach is increasingly relevant for research, where data sources are very diverse and globally distributed. The use of FAIR Digital Objects (FDOs) enables data within and between these areas to be permanently linked, traced, and reused, thereby improving reproducibility, machine processability, and collaboration. Considering how much data there is in a wide variety of disciplines with a spatial and temporal reference, SpatioTemporal Asset Catalog (STAC) offers an open metadata standard for organizing geospatial and temporal data, which is already widely used by European initiatives such as ESA's Destination Earth the Copernicus Data Space Ecosystem, and other initiatives listed on stacindex.org. Integrating STAC with FDO principles enables machine-actionable, interoperable catalogues within research data spaces, supporting the European Open Science Cloud (EOSC) ambition for a “Web of FAIR Data and Services” advancing cross-domain research. In this work, STAC has been defined as FDOs, but the challenges of dealing with varying catalog contents, data access mechanisms, and the linking of catalogue and the data with operational processes are also considered and addressed. (presented at 3rd FAIR Digital Objects Conference, Vienna. 25.-27.03.2026. https://fairdo.org)