The ever-increasing interest from academia, industry, and governmental institutions in space resources information has highlighted the difficulty of finding, accessing, integrating, and reusing the related knowledge. All this knowledge is disseminated in scientific publications, patents, news, and reports, which are regularly made available to the community on the Web through many media and in different formats. In collaboration with the European Space Agency, we are currently developing a knowledge management platform in the field of space resources. This tool, based on the use of Semantic Web technologies such as knowledge graphs and ontologies, aims to formalize the knowledge of the domain contained in the documents mentioned above and to make them available to the community. In this article, we describe the concepts and techniques of knowledge extraction and knowledge management implemented for the design and implementation of such a platform.