WASHINGTON — A Russian Proton rocket carrying the Express AM4R telecommunications satellite for the Russian Satellite Communications Co. (RSCC) failed shortly after liftoff May 16 from the Baikonur Cosmodrome in Kazakhstan, the Russian space agency, Roscosmos, announced.

In a brief press release posted on its website, Roscosmos said a problem occurred with the third stage of the workhorse vehicle. The heavy-lift Proton has now failed five times since late 2010, all on Russian government missions.

A state commission has been formed to investigate the mishap, Roscosmos said.

According to an English translation of the Roscosmos press release, the Express AM4R spacecraft did not reach orbit.

As was the case with the previous four Proton failures, including a spectacular crash last July, International Launch Services, which markets Proton commercially, was not involved in the Express 4AMR mission. However, the company has upcoming commercial Proton launches on its manifest, including missions for satellite operators SES and Inmarsat.

It is unclear whether the schedules for these commercial missions will be affected by the failure. However, Roscosmos is known for quickly returning vehicles to flight following failures.

The Express AM4R satellite was built for RSCC, Russia’s top satellite fleet operator, by Airbus Defence and Space of Europe. The satellite, carrying 36 C-band, 28 Ku-band, three L-band and two Ka-band transponders, was intended to replace the Express AM4 satellite that was lost in a Proton failure in mid-2011.

Peter B. de Selding was the Paris bureau chief for SpaceNews.