Alphasat is a large telecommunications satellite primarily designed to expand Inmarsat’s existing global mobile telecommunication network. It was engineered and built by Astrium through a public–private partnership (PPP) between ESA and Inmarsat.
It is the largest European telecom satellite ever built, exceeding 6.6 tonnes at launch. Its solar array, spanning almost 40 m, generates more than 12 kW of power.