Alphasat

Alphasat is a European telecommunications satellite developed as a joint mission of the European Space Agency (ESA) and Inmarsat. Its primary purpose is to serve as a technology demonstrator for next-generation large communications satellites and to test advanced payload technologies that could inform future European space infrastructure. The mission carries Inmarsat’s Ka-band payload to support high-speed data services and to validate new on-board processing and antenna concepts.

The spacecraft was built on the Eurostar E2000+ platform by Astrium (now part of Airbus Defence and Space) and features a sizeable bus designed for a geostationary orbit. Its launch mass is reported in the vicinity of several metric tons, with power available to support its payload and experiments. Alphasat was designed to host a Technology Demonstration Payload (TDP) in addition to the primary telecommunications payload, enabling a range of European experiments in areas such as high-rate data transmission and beamforming technologies.

Alphasat was launched on July 25, 2013, aboard an Ariane 5 rocket from the Guiana Space Centre in Kourou. After deployment, it was placed into a geostationary transfer orbit and subsequently positioned at a GEO slot to support Inmarsat’s services. The mission life was planned to extend over a decade, contributing to the evolution of Europe’s space-based communications capabilities.

As a flagship European technology demonstrator, Alphasat highlighted European capabilities in satellite design and hosted payload experiments, illustrating a pathway for future large-scale telecom satellites and collaborative space programs between ESA and industry.