Glonass-M delivered to orbit

Russian navigation satellite developed under Glonass system was launched today in the morning from Plesetsk cosmodrome.

This mission was planned as second in 2016 launch of satellite from Glonass-M generation. Objective of the mission is to place satellite on 19132 km x 19158 elliptical orbit with inclination at 64.8° to improve capabilities of Glonass system (Globalnaya Navigationnaya Sputnikovaya Sistema-Global Orbiting Navigation Satellite System). Mission of the satellite will last seven years. Roscosmos decided about using Soyuz-2.1B rocket with Fregat-M and lunch site 43/4 in Plesetsk cosmodrome in Arkhangelsk Oblast. Liftoff took place punctually at 08:45 GMT and it was third rocket from Soyuz-2.1 series launch from Plesetsk in 2016. After deployment of the satellite at 12:16 GMT satellite will operate under codename Kosmos-2516. Roscosmos is still developing Glonass and it is planned that until end of the 2017 additional eight Glonass satellites will be launched. Unfortunately next generation of improved Glonass-K generation satellites smaller and with improved lifespan, is planned to be put into mission schedule not earlier than in 2018.

Glonass-M satellites are second generation of navigation satellites operating under Glonass system. They were designed and are manufactured by NPO Prikladnoi Mekhaniki. They remain in service since first launch on atop of Proton-K in 2001. Since then, 61 Glonass satellites were built with 42 launched and with number of remaining operational of 24. Each satellite weighs 1415 kg and is powered by two deployable solar arrays and onboard NiH2 battery which are providing 1250W of power. Satellite is equipped in 3 axis stabilization system; navigational payload is based on L band transmitters for emitting navigational signal in 25 channels on 1602.5625 - 1615.5 MHz and 1240 - 1260 MHz frequencies with 0.5625 MHz intervals. Additional payload is 3 precision cesium clocks and Laser Ranging device. Glonass-M satellites are able to autonomously switch to sun pointing mode for power in five hours and to Earth pointing mode for communication with ground control for 4- 6h radio contact windows.

Soyuz-2.1B rocket with  Fregat-M upper stage is proven launch vehicle for Glonass satellite. It was used for the first time for Glonass-M mission in 2011. It is liquid fueled (LOX/Kerosene) rocket with four strap-on boosters. Length is 46 m with mass at 308000 kg. Each booster is equipped with single RD-107A with thrust at 838.5 kN and burns 44413 kg of propellant. Core stage is powered by one RD-108A with thrust at 792.5 kN and fueled with 90100 kg of propellant. Second core stage is equipped in one RD-0124 generating thrust at 297.9 kN and if fueled with 25400 kg. For final injecting into orbit during this mission Fregat-M upper stage was used. It weighs 902 kg and takes 5600 kg of N2O4/UDMH propellant for one S5.92 engine which gives 19.85 kN of thrust. GTO payload capacity with Fregat-M upper stage is 3250 kg.