MOSCOW, May 30. /TASS/. An irregularity occurred when the Soyuz-2.1b carrier rocket’s third stage was orbiting a Glonass-M satellite from the Plesetsk spaceport in Russia’s northwestern Arkhangelsk region on Sunday, a source in the Russian space rocket industry told TASS on Monday.
"The Fregat upper stage worked longer than planned and used its engines to remedy the situation. A state commission is probing into the accident," the source said.
According to him, the upper stage successfully placed the satellite into the target orbit and then Fregat entered the disposal orbit.
The Russian Defense Ministry’s press service reported earlier that stable telemetry link was established and maintained with the Glonass-M satellite. The spacecraft’s onboard systems are functioning normally.
According to the rocket and space industry source, the testing of the satellite before its putting into service will last for about a month.
The Soyuz-2.1b carrier rocket was launched at 11:45 am, Moscow time (08:45 GMT) on Sunday from site No 43 of the Plesetsk cosmodrome in the Arkhangelsk region in north Russia by an operational crew of the Russian Aerospace Force’s space troops.
Ten minutes after the launch, the carrier rocket’s upper stage comprising a Fregat booster and the Glonass-M navigation satellite separated from the rocket in a normal mode. The satellite’s further injection into orbit was carried out by the Fregat acceleration unit.
This is the second launch of a Glonass-M satellite and the third launch of a Soyuz-2 medium-class carrier rocket from the Plesetsk cosmodrome this year.
As Roscosmos State Corporation said earlier, up to eight satellites may join the Glonass system constellation by the end of 2017. Both Soyuz launch vehicles and Proton-M heavy carrier rockets may be used for the launches. A source in the space rocket industry told TASS that the launch of a Proton carrier rocket with three Glonass satellites may take place already before the end of 2016.
Glonass is Russia's satellite navigation system designed to provide Russia with its own navigation data for military and civilian use, as well as to compete with the US Global Positioning System (GPS) in the commercial market for navigation data.
Aside from the satellite launched on May 29, Russia’s Glonass orbital constellation comprises 28 satellites, of which 24 are used according to their target designation while two spacecraft are in the operational evaluation of the chief designer, one in the orbital reserve and the other one at the stage of flight tests.