The agency added that the separation of the satellite from the carrier rocket in the designated orbit was scheduled for 12:17 Moscow time (8:17 GMT).
Initially, the lift-off of the Russian telecoms satellite was scheduled for December 2. However, the event was postponed until December 16 amid the delayed launch of Europe's Astra-2G. Last week the launch was moved again for December 15.
The Yamal-401 satellite, designed and built by ISS-Reshetnev Company for Russian operator Gazprom Space Systems, is capable of continuously relaying signals in Europe and Asia. The satellite has 53 transponders and six antennas in C/Ku-bands.
The Yamal-401 is the third spacecraft built on the basis of a heavy-class Express-2000 platform. The mass of the satellite is 2,976 kg, the power used to carry the payload is 11 kWt, and the life span is 15 years.