A broadband satellite will open a window to the internet for hundreds of thousands of cut-off consumers across Europe.
The £120 million Hylas-1 satellite will act as a relay station for broadband traffic, enabling isolated rural communities to connect with the world wide web for the first time.
Hylas is the first superfast broadband satellite to be launched outside the US.
It will be carried into orbit by an Ariane 5 rocket which was launched from French Guyana last night.
The satellite's development was partly funded by the UK Space Agency, and designed and built for Avanti Communications by British space company Astrium UK.