DirecTV-7S, a geostationary satellite designed to beam services to 60 local markets in the United States, was taken aloft at 1242 GMT by a Ukrainian-made Zenit-3SL rocket, launched from a mobile platform in international waters in the Pacific, Sea Launch said on its website.

"A ground station in Weilheim, Germany, acquired the spacecraft signal. All systems are operating normally," Sea Launch said.

The 5.5-tonne satellite, built for the US digital multichannel television provider DIRECTV, was initially to have been launched in late 2003 by Arianespace, which markets the European Space Agency's Ariane rocket.

But that launch was scrapped in order to make way for the long-postponed deployment of ESA's comet-chasing spacecraft Rosetta, which eventually lifted off on March 2.

To meet its contractual needs, Arianespace invoked a cooperation agreement that it had only just signed with two other launch companies: Boeing Launch Services, representing Sea Launch, and Mitsubishi Heavy Industries of Japan.

Under the three-way "launch services alliance" struck last July, the companies agree to provide backup launches if one of their number cannot cope with an order.

Sea Launch is owned by Boeing (40 percent), RSC-Energia of Russiapercent), Kvaerner of Norway (20 percent), and SDO Yuzhnoye/PO Yuzhmash of Ukraine (15 percent).

SPACE.WIRE