The rocket, which was launched from the Baikonur space center in Kazakhstan at 2:43 a.m. Moscow time (10:43 p.m. GMT Wednesday), experienced an engine malfunction and second-stage separation failure 139 seconds into its flight, and came down in the central Kazakh steppe, 50 kilometers (30 miles) southeast of the town of Dzhezkazgan, the spokesman said.
The rocket was carrying highly toxic heptyl rocket fuel, and an investigative team will soon be sent to determine the extent of any environmental damage that may have resulted from the crash, he said.
Although Russia and Kazakhstan have an agreement on launches from Baikonur until 2050, for which Moscow pays Astana $115 million a year, Kazakhstan recently said it would reconsider allowing further flights of the Proton because of the rocket fuel's toxicity and potential for catastrophic environmental contamination in the event of a launch failure.
The satellite was owned by JSat Corp. and would have provided communications links for Japan, the Pacific Region and Hawaii. The company currently operates eight geostationary communications satellites.
The Delaware-registered company International Launch Services (ILS), which organized the launch, is a Russian-American joint venture that has orbited 41 commercial payloads since 1996.
Last year, a Russian Dnepr rocket crashed on lift-off from Baikonur, after which a special commission was formed to assess the resulting environmental damage. On the basis of its findings, Russia paid Kazakhstan $1.1 million in damages.