It said a Zenit-3SL vehicle will lift the 5,511 kg (12,150 lb) spacecraft to Geosynchronous Transfer Orbit from the Odyssey Launch Platform, positioned on the Equator in the Pacific Ocean.
The EchoStar XI will expand DISH Network's capacity to its direct broadcast satellite TV customers throughout the United States.
The Sea Launch consortium, established in 1995, is owned by Boeing, Norway's Kvaerner ASA, Ukraine's Yuzhnoye design bureau and Yuzhmash production association, as well as Russia's RSC-Energia. It is the only company that launches its vehicles from the Equator, which allows rockets to carry heavier payloads than from other latitudes.
Sea Launch has performed a total of 27 commercial launches for a range of companies, including EchoStar, DirecTV, XM Satellite Radio and PanAmSat.
The Zenit-3SLB is a modernized version of the Zenit-3SL, which was the rocket previously in use at Sea Launch's floating platform in the Pacific Ocean.
