Sea Launch AG says a U.S. communications satellite was lost after a booster rocket carrying it into space failed shortly after its launch from a floating platform in the Pacific.

The company said in a statement Friday the Intelsat 27 satellite was lost 40 seconds after the launch due to the failure of the Zenit-3SL rocket. The Boeing. Co-built spacecraft was launched Thursday from the Odyssey ocean platform.

Sea Launch AG President Kjell Karlsen said the cause of the failure is unknown and the company is working to evaluate it.

An affiliate of Russia’s RKK Energia state-controlled rocket manufacturer owns 95 percent of stock in Sea Launch, with the remainder being held indirectly by Boeing Co. and Norwegian Aker ASA. The Zenit booster is manufactured by Ukraine’s Yuzhmash rocket plant.