Russia launched another Glonass-M navigation satellite Nov. 28, continuing a replenishment effort that has seen a total of six Glonass satellites added to the constellation since three craft were lost to a launch failure last December.

ISS Reshetnev, the Krasnoyarsk, Russia-based company that built the satellite, said the latest Glonass-M satellite was successfully injected into orbit following liftoff aboard a Soyuz rocket from the Plesetsk Cosmodrome in Northern Russia at 12:26 p.m. Moscow time.

The day of the launch, the Russian space agency, Roscosmos, said 23 Glonass satellites were currently in operation, two were temporarily out of service and one was being held in reserve as a spare. The four satellites launched Nov. 4 were undergoing on-orbit checkout in preparation for entering service. A next-generation Glonass-K satellite launched in February is undergoing flight testing.

“Having launched these satellite we have made an important step towards creating an orbit reserve,” ISS Reshetnev Director General Nikolay Testoyedev said in a statement. “The availability of two reserve satellites in each of the three orbital planes will enable us to replenish the system within several days or weeks, but not months and years as it used to be before.”

The Russian government has been investing heavily in recent years in restoring the Glonass system, which fell into neglect following the collapse of the Soviet Union.