Three GLONASS-M spacecraft, Cosmos 2447 (Glonass 727), Cosmos 2448 (Glonass 728), Cosmos 2449 (Glonass 729) were added to the Russian global navigation satellite system. They were launched by a Proton-M rocket with a Block DM upper stage from Baikonur on 25 December 2008 at 10:43 UT. The spacecraft are designed to last at least seven years. The Glonass system currently consists of 20 satellites, of which 16 are operational, the three newest are in their commissioning and test phase, and one is due to be withdrawn.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.