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Russian Proton rocket fails on satellite mission

Anatoly Zak, Spaceflight Correspondent
May 16, 2015, 17:18 UTC, Updated May 16, 2015, 23:13 UTC

Sen—The Russian space program has suffered another launch failure, crippling its commercial operations, just weeks after a major accident grounded the main carrier of its human missions.

The Proton rocket lifted off from Baikonur Cosmodrome in Kazakhstan on Saturday, May 16, carrying the MexSat-1 communications satellite for the Mexican government. The initial phase of the flight seemed to go smoothly until an official commentator suddenly declared a "non-nominal situation" and interrupted the live broadcast of the launch slightly more than eight minutes into the flight, during the operation of Proton's third stage.


A nominal flight profile of the Proton rocket with the MexSat-1 communications satellite.

The International Launch Services (ILS), which markets Proton missions to commercial customers around the world, also covered the initial phase of the mission live, however could not confirm the status of the rocket or the satellite by the end of its broadcast. The company's representative admitted some loss of telemetry from the mission, however reported that other available information, including data from NORAD radar had indicated a normal flight.

After several minutes of confusion, the official Russian media reported that the launch had failed during the operation of the rocket's third stage. According to the Interfax news agency quoting unnamed sources, the remnants of the vehicle had been expected to crash in the Chita Region in Eastern Russia.

According to preliminary analysis of available telemetry, a failure of steering engines on the third stage could have caused the accident, the agency reported.

In the meantime, an online broadcast of key mission milestones based on the livetelemetry from the launch came with a considerable delay and stopped before the planned engine cutoff on the third stage of the Proton rocket.

Around half an hour after the accident, the Russian space agency (Roscosmos) announced that a "non-nominal situation" had taken place during the Proton launch and its cause had to beinvestigated.

The same press-release also said that a planned orbit correction of the International Space Station (ISS) with the engines of the Russian Progress cargo ship had not taken place either.

A similar Progress ship was lost moments after its separation from the third stage of the launch vehicle on April 28. Although the root cause of the accident still remains unknown, the Soyuz-2-1a rocket was blamed, leading to a domino effect of delaysin the operation of the ISS.

After the latest accident with the Proton, the two main rocket families in the Russian rocket fleet are out of commission.