Inmarsat successfully launched the first of its new generation of satellites on Friday, bringing it one step closer to offering 3G-compatible broadband data services to mobile users.

The six-ton Inmarsat 4 (I-4) satellite, the size of a London double-decker bus, took off from Cape Canaveral, Fla., and will now undergo post-launch tests and maneuvers, the U.K. satellite company said. It is the first of three I-4 satellites that will supply Inmarsat's coming menu of Broadband Global Area Network (BGAN) services, due in the fourth quarter of this year.

The BGAN services will offer data speeds of up to 432K bit/sec for applications such as video on demand, phone, e-mail, and Internet access. Inmarsat's satellite services are used by maritime vessels, military units and other customers that need roaming capabilities in remote areas.

The second I-4 satellite is set to take off in the third quarter, and a third satellite, which will provide mostly redundant coverage for the first two, will follow at a later, unspecified date.

The satellites are being built by European Aeronautic Defense and Space Co. subsidiary EADS Astrium as part of an eight-year, $1.5 billion development plan to build Inmarsat's next-generation network. The satellites have a lifespan of about 14 years, according to an Inmarsat spokesman.

The IDG News Service is a Network World affiliate.