Both the rocket and the satellite were built by Lockheed Martin Corp. , which is also a partner in the ILS joint venture. This was the fifth launch for ILS in 2004, four of which have been on Atlas rockets. This also was the 72nd consecutive successful launch for the Atlas vehicle family.

The Atlas IIAS rocket lifted of from Cape Canaveral's Launch Complex 36B at 6:22 p.m. EDT (2222 GMT). The satellite, an A2100 model, was injected into a transfer orbit 28 minutes later. The AMC-11 spacecraft is a twin to AMC-10, launched in February, and together they form SES AMERICOM's premier cable neighborhood and the platform for its HD-PRIME service.

"We're proud to deliver another satellite on target for SES AMERICOM," said ILS President Mark Albrecht. "We look forward to the same success with our two Proton launches this summer with WORLDSAT 2 and AMC-15, and the AMC-16 mission scheduled for an Atlas V at the end of this year. You could say SES AMERICOM is an ILS Frequent Flyer."

Albrecht noted the long-standing relationship shared by ILS, SES AMERICOM and its parent company, SES GLOBAL. To date ILS has launched 16 satellites for companies affiliated with SES GLOBAL, including seven for the SES AMERICOM fleet. Last month, the companies announced that three additional satellites for SES AMERICOM and SES ASTRA will be launched on ILS vehicles.

Dean Olmstead, president and CEO of SES AMERICOM, said: "We have great confidence in ILS, as evidenced by our recent experience with the Atlas IIAS and Proton launch vehicles. We are optimistic that the two Proton launches scheduled for August and October, as well as our first Atlas V launch in December, will be just as flawless as tonight's AMC-11 Atlas IIAS launch."

ILS has established itself as the indisputable leader of launch services worldwide and offers the industry's two best launch systems: Atlas and Proton. With a remarkable launch rate of 63 missions during the past three years, the Atlas and Proton launch vehicles have consistently demonstrated the reliability and flexibility that have made them the vehicles of choice. Further demonstrating ILS as the industry leader, ILS has signed more new contracts than its competitors combined over the same three-year period. By any measure, ILS is truly the global leader.

ILS is a joint venture of Lockheed Martin and Russian rocket builder Khrunichev State Research and Production Space Center. ILS markets and manages the missions on the Atlas rocket in the United States and on the Proton rocket at the Baikonur Cosmodrome, Kazakhstan. ILS was formed in 1995, and is based in McLean, Va., a suburb of Washington, D.C.