Eutelsat has decided to launch the new W3B satellite on an Ariane 5 rocket, rather than on a Long March 3B, to remain on schedule.

The W3B is scheduled to replace its predecessor, W2, which unexpectedly became non-functional in January 2010, according to Spaceflight Now.

W2 had been serving Europe, Africa and the Indian Ocean region and its failure forced Eutelsat to gather three different spacecraft to cover for the loss in communications service at the 16°E longitude position.

The W3B, being built by Thales Alenia, was initially designed to contain non-US components to enable its launch on the Chinese Long March 3B.

Spacecraft with US components are banned from launching on Chinese rockets under international traffic in arms regulation (ITAR) rules.

To launch the satellite on time the firm, however, has exercised the option of swapping the rocket with Ariane 5, while W3C will be launched on the Chinese rocket in September 2011.