Watch the launch of Inmarsat's Alphasat I-4A F4 satellite live from the European Spaceport in Kourou, French Guiana.
The launch is scheduled for 19:53 UTC (20:53 BST) on Thursday, 25 July.
After lift-off, the flight sequence will last nearly 33 minutes, with Alphasat deployed at just under 28 minutes after launch.
Alphasat is Europe's largest ever telecommunications satellite – the result of a public-private partnership space project between Inmarsat and the European Space Agency (ESA).
Configured with an advanced, new generation L-band geo-mobile communications relay system, the satellite will augment Inmarsat's industry-leading I-4 broadband network and provide increased capacity for mobile communications across Europe, Asia, Africa and the Middle East.
Watch the launch: www.arianespace.tv
