Themis reusable rocket prototype arrived at Esrange Space Center in Sweden

On June 27, 2025, Themis, reusable first stage demonstrator developed with support from the European Space Agency (ESA), arrived at the Esrange Space Center in Sweden, where will be host the first-ever reuse tests in Europe as part of the SALTO project, part of the Space Research and Innovation (R&I) Work Programme, of the European Union. The demonstrator has now reached its final assembly building, where ArianeGroup's teams will complete integration of the experimental payloads prepared by partners in the SALTO project before finalizing the demonstrator's preparation and flight configuration. Themis will then be erected on its launch pad for the first time. In the coming weeks, the initial phases of the test campaign — known as the “combined tests” — will begin, paving the way for a first low-altitude test flight. Themis, powered by the Prometheus® reusable engine, was designed and assembled by ArianeGroup's teams in Les Mureaux, France. Both the Themis and SALTO development projects are following a test-and-learn approach, taking calculated risk to maximize data collection throughout the test campaign.