At Eutelsat's request, and by mutual agreement with ILS, the decision to postpone the launch was made after technical issues emerged during prelaunch processing on the Eutelsat W4 spacecraft that could have delayed the planned April 14 launch.

Eutelsat said in a statement that "in accordance with Eutelsat's policy, as a commercial satellite operator, of providing its clients with the highest quality of service, an additional series of tests will be carried out by industry on part of the equipment installed on W4's propulsion system. "This measure has been decided in order to ensure full confidence in the performance of the satellite throughout its expected 12-year lifetime," the statement added.

The Lockheed Martin engineering team will take advantage of the delay to perform additional validation of interface loads on the duct of the Centaur upper stage's overboard vent system.

Each new Atlas configuration has flown successfully in its maiden flight with a paying customer aboard. The Atlas performance record also includes a string of 48 consecutive successful launches.

Atlas III is the next step in Lockheed Martin's logical, evolutionary approach to next-generation launchers and a bridge to the Atlas V family which will make use of flight proven hardware from Atlas III.

The launch of AC-201 will demonstrate the first use of the RD-180 engine on the Atlas booster and the new single-engine Centaur configuration.

Built by Alcatel Space, W4 will join Eutelsat's 15-satellite fleet and provide Ku-band capability for digital pay television and broadband Internet access to Russia and sub-Saharan Africa. W4 is built by Alcatel Space Industries of Cannes, France.