PARIS — The head of Russia’s Roscosmos space agency on Dec. 7 said all launches of the Proton vehicle will be suspended until a board of inquiry has determined the cause of the Dec. 5 Proton failure, which destroyed three Glonass navigation satellites.

In statements posted on the Roscosmos website following an interview with Russia’s Izvestia news service, Anatoli N. Perminov also said a demonstration model of the next generation of Glonass satellites will be put into operational service to offset the loss of the three earlier-generation spacecraft.

The launch of the first Glonass-K satellite, now undergoing final testing at ISS Reshetnev in Krasnoyarsk, Russia, is scheduled later this month aboard a Soyuz rocket.

Perminov said he hopes the inquiry board will return its conclusions by the end of this month, and perhaps even within two weeks.

“Until we reach conclusions about the cause of the failure, Proton won’t be launched,” Perminov said. “We have one more launch of this rocket, with a foreign payload, on this year’s schedule.”

An International Launch Services (ILS) Proton using a different upper stage than the one used for the failed Glonass launch is scheduled to launch the Ka-Sat consumer broadband satellite for Eutelsat of Paris late this month.

International Launch Services on Dec. 7 released the following statement about its Ka-Sat launch preparations.

“We expect to receive an interim [Proton failure] report in approximately one week that may include details on the respective performance of the Block DM-03 upper stage built and operated by RSC Energia and the three lower Proton M stages, all built and operated by Khrunichev Research and State Production Center, the majority owner of ILS. While the Proton M is a flight-proven configuration, this was a maiden flight of the Block DM-03 upper stage, which is a derivative of Energia’s Block DM-3.

“The Ka-Sat satellite built by Astrium for Eutelsat is scheduled for launch on December 20 using the Proton M Breeze M launch vehicle. The Breeze M upper stage, like the Proton M stages, is built and operated by Khrunichev. The Ka-Sat satellite launch campaign continued with the completion of the spacecraft propellant loading yesterday, and the start of joint operations today with mating to the payload adapter system. 

      

“Further information will be provided on the status of the December 5 Proton M Block DM-03 GLONASS-M mission investigation as well as the upcoming ILS Proton Ka-Sat launch as soon as it becomes available,” the statement concludes.

Perminov said the Proton rocket, which for ILS launches uses the Breeze M upper stage and for some government launches uses the older Block DM stage, remains one of the world’s most reliable vehicles, with a 96 percent success rating. He noted that the Breeze M caused a Proton launch failure in 2008, and that the Block DM stage “has not had any problems … for almost 15 years. Proton DM has launched six Glonass satellites in 2010, and the injection accuracy was very high.”

Perminov said the Dec. 5 launch used a Block DM with a newly modified, digital control system, and that this could be one focus of the board of inquiry. But he cautioned it was too soon to point to any single cause.

After a major government investment to return the Glonass constellation to full service over Russian territory, and then to a global utility on par with the U.S. GPS navigation and timing constellation, the Glonass system now counts 20 operational satellites and two in-orbit spares, Perminov said. While only 18 operational satellites are needed for full Russian coverage, it takes 24 to provide a global service.

With a Glonass-K satellite launching aboard a Soyuz vehicle with a Fregat upper stage from northern Russia’s Plesetsk spaceport in the coming weeks, and the integration of the two in-orbit spares, the constellation will have 23 operational spacecraft.

ISS Reshtnev is completing another Glonass satellite, presumably a Glonass-K version, that Perminov said would be ready for launch in three or four months. The possibility of accelerating production of other Glonass satellites is under study, he said.

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