Russia plans to launch four satellites for the GLONASS navigation system by the end of this year, the Aerospace Defense Forces head said.
"Three GLONASS satellites are scheduled to be launched on board of a Proton carrier rocket in July from the Baikonur space center and another one is planned to be launched in December from the Plesetsk space center," Maj. Gen. Alexander Golovko said.
The most recent launch of the GLONASS satellite took place on April 26, when a Soyuz 2-1b rocket blasted off from the Plesetsk space center to orbit a GLONASS-M satellite, according to reports.
The Global Navigation Satellite System (Glonass), which was officially launched in 1993, is only the second worldwide navigation system to be fully operational following the U.S. GPS.
It provides data for real-time positioning and speed of surface, sea and air objects to within an accuracy of one meter.
The Glonass program was initiated in the 1970s but underwent a radical revamp in 2001. The 24 satellites comprising the system had been put into orbit by 2010, though only after several costly malfunctions and launch failures by carrier rockets.
The program has cost 140 billion rubles ($4.4 billion) to implement to date, and its budget for 2012-2020 stands at a further 326 billion rubles ($10 billion).