Glonass - the Global Navigation Satellite System - is the Russian equivalent of the U.S. Global Positioning System, or GPS, and is designed for both military and civilian use. Both systems allow users to determine their positions to within a few meters.
"The launch of the Proton-M carrier rocket with Glonass-M satellites on board was made on schedule at 13:43 Moscow time [10:43 GMT], and the separation of the satellites from the spacecraft is due to occur at 17:15 Moscow time [14:43 GMT]," the Roscosmos spokesman said.
This is the second successful launch of the Glonass mission this year. The first launch of three Glonass satellites was carried out on September 25.
According to Roscosmos, Russia carried out a total of 27 launches in 2008, beating last year's previous record of 26 launches. The latest launch is the 10th in 2008 involving Proton-M carrier rockets.
The Russian space agency announced earlier this month it planned to make a total of 39 launches in 2009 from the Baikonur space center and the Plesetsk space center, in northwest Russia.
The Glonass system currently consists of 19 satellites, of which 16 are operational, two are undergoing maintenance, and one is due to be withdrawn. The system requires 18 satellites for continuous navigation services covering the entire territory of the Russian Federation, and 24 satellites to provide services worldwide.
A total of 9.9 billion rubles ($360 million at the current exchange rate) was allocated for Glonass from the federal budget in 2007, and 4.7 billion rubles ($170 million) in 2006.
Russian Prime Minister Vladimir Putin signed a directive on September 12 allocating an additional $2.6 billion to develop the system.
Roscosmos chief Anatoly Perminov said in September that the number of satellites in the Glonass network would be increased to 30 by 2011.