Soyuz-2.1B • Glonass-M


Russia is going to launch next Glonass satellite in the end of December 2015. It is planned to utilize Soyuz-2.1B version with Fregat upper stage. Glonass-M is result of work and experience of engineers from NPO Prikladnoi Mekhaniki (present name is Reshetnev Information Satellite Systems). It is medium satellite with weight at 1415 kg and operational life at seven years; it is powered by two deployable solar arrays. Stabilization of satellite is in 3 axis. Main equipment of Glonass-M (another name is Uragan-M) is L band transponder and cesium clocks. Navigation signal is broadcast in 0.5625 MHz intervals, on 25 channels in two frequency ranges: 1602.5625 MHz - 1615.5 MHz and 1240 MHz - 1260 MHz. Additional civil navigation signal is broadcasted on L2 band and should improve civilian Glonass accuracy (Glonass offers civilian accuracy to 100 m and for military purpose it is 10 m -20 m). Effective isotropically radiated power (EIRP) for transponder fits in the range 25 dB - 27 dB. Designated launch vehicle will be Soyuz-2.1B with Fregat-M upper stage. Fregat is liquid fueled (UDMH and N2O4) single engine (one S5.92 with thrust at 19.61 kN) vehicle with capability of being restarted up to 25 times. Its height is 1.5 m, diameter is at 3.5 m and mass of propellant is 5350 kg, dry mass of the Fregat-M is 6500 kg. Launch is delayed, status is TBD.