The GLONASS orbital group has the necessary reserve to work efficiently, Russian Deputy Prime Minister Dmitry Rogozin said at a meeting at the Government House on Friday.

"The developed space group of the GLONASS system has the necessary orbital reserve and the crash which happened should not lead to the decrease of its efficiency, however it is necessary to compensate for the loss of satellites in the future," Rogozin said.

The Proton-M rocket, launched at the Baikonur cosmodrome on July 2, was to put into orbit three GLONASS satellites. The rocket fell and exploded near the launch site within minutes.

Early launch likely cause of Proton-M failure
Early launch is seen among the most likely cause of the recent Proton-M rocket failure and the loss of three satellites, a Russian space industry source familiar with the investigation said on Thursday.

The source said a special commission is still investigating the incident, several versions are being considered.

One of the versions is that, for yet unknown reasons, an early start took place and resulted in the failure. The control system treated it as an emergency situation... and started to divert the rocket away from the launch pad, the way it was programmed. This version prevails," the source said.

The Proton-M rocket was carrying three Glonass navigation satellites when it exploded shortly after launch early on Tuesday from the Baikonur space center in Kazakhstan.

Rocket crash may be due to premature engines ignition: space agency
The failed launch of the Proton-M rocket this week could be caused by premature launch, head of the Russian space agency Roscosmos said on Friday.

"This is obvious that the rocket blasted-off before its engines started work on full capacity," Vladimir Popovkin told reporters.

According to Popovkin, the rocket engines were ignited 0.4 seconds before the planned time.

He said the reason why the lift-off happened prematurely should be investigated.

Experts consider various other possibilities, including malfunctions in the launch-pad equipment, rocket guiding device and first-stage engines, he added.

Investigation must be completed in July, Popovkin added.

The Proton-M carrying three communications satellites crashed Tuesday 17 seconds after lift-off from the Baikonur space center in Kazakhstan. The rocket fell about 2.5 km away from the launch pad.

Another Proton-M rocket also failed to reach orbit in 2012.

Source: Voice of Russia