Soyuz 2.1b launches new GLONASS-M navigation satellite
Russia has continued the expansion of its GLONASS constellation with the Saturday, Nov. 3, 2018 launch of a Soyuz 2.1b rocket from the Plesetsk Cosmodrome located in northern Russia.
The GLONASS-M (GLONASS-M No. 757) spacecraft that was sent aloft will now become part of Russia’s Global Navigation Satellite System (GLONASS). The rocket and its payload took to the late evening’s skies at 11:17 p.m. Moscow time (20:17 GMT / 3:17 p.m. EST) from Plesetsk’s Pad 4 at Site 43.
While the flight of a navigational satellite might seem to be small potatoes, last night’s flight was attended by the Commander of the Space Troops and Deputy Commander-in-Chief of the Aerospace Force Colonel General Alexander Golovko.
One hour and 20 minutes after it had left the pad, it was declared that the mission was a success by the Russian Defense Ministry.
“On Saturday, November 3 at 23:17 Moscow time the operational crew of the Space Troops of the Aerospace Force successfully launched the Soyuz 2.1b medium capacity carrier rocket with the GLONASS-M navigation spacecraft from launching unit 4 at platform 43 of Plesetsk Cosmodrome (Arkhangelsk Region),” the Russian Defense Ministry stated via the government-owned TASS press agency.
The pre-launch campaign for GLONASS-M got underwat in early October with the arrival of the spacecraft at Plesetsk. Throughout the month the engineers were busy conducting checks and fueling operations of the satellite. The launch vehicle was fully assembled in late October and rolled out to the launch pad on October 31. However, its flight could have been ended up taking place much later.
With the failure of a Soyuz-FG rocket to send two crew members to the International Space Station on Oct.11, it was feared the GLONASS-M launch might slip further. With the cause of that accident determined to be a faulty sensor, pre-launch activities for the GLONASS-M mission got back on track.
That mission kicked off with the roar of RD-107A engines which pushed the rocket off of the pad and into the night. After completing a short vertical climb the four boosters mounted to the side of the rocket were jettisoned after approximately two minutes into the flight.
For Saturday’s mission, the Soyuz 2.1b rocket flew in a configuration that used a Fregat-M third stage. That upper stage measures about 4.9 feet (1.5 meters) long and 11 feet (3.35 meters) in diameter. Its S5.92 engine is designed to burn for a period of about 18 minutes.
Once this stage of the flight was complete, the core stage assumed control over the mission and powered the launch vehicle until it was detached at about four-and-a-half minutes after liftoff.
Afterward, the third stage ignited and controlled the flight for nearly seven minutes. Then, at about T+10 minutes, the Fregat-M upper stage separated from the third stage and commenced its three-hour trek which culminated with the satellite being inserted into a circular medium-Earth orbit (MEO) at an altitude of approximately 11,800 miles (19,000 kilometers), inclined 64.8 degrees toward the equator.
When GLONASS-M No. 757 reached its targeted orbit, it received the official designation Kosmos 2529. The new satellite is planned to be a replacement for one of the GLONASS spacecraft currently in service. Russia has not disclosed which of these it will replace.
GLONASS-M satellites, also known as Uragan-M, are the second generation of Uragan satellite designs that are used as part of the Russian GLONASS radio-based navigation system. A typical GLONASS-M spacecraft, developed by the Reshetnev Information Satellite Systems (ISS Reshetnev) and operated by the Russian Aerospace Defense Forces, measures about 7.87 by 12.14 feet (2.4 by 3.7 meters) and has a launch mass of some 1.4 metric tons.
The GLONASS system provides real-time position and velocity data for both military and civilian users. All the satellites are located in a middle circular orbit at about 11,800 miles (19,000 kilometers) altitude with a 64.77-degree inclination at a period of 11 hours and 15 minutes. They provide an accuracy of 328 feet (100 meters) as part of the public segment and 33 to 66 feet (10 to 20 meters) for military purposes.
The system operates in three orbital planes, with eight evenly-spaced satellites on each plane. A total of 24 satellites are required to guarantee global coverage, while 18 are necessary to cover the territory of Russia.
As the rocket’s nomenclature suggests, this version of the rocket is an upgraded version of an earlier design – the three-stage Soyuz 2 launch vehicle. The Soyuz 2.1b stands an imposing 151-feet (46.1-meters) in height and has a total mass of 672,000 pounds (304,814 kilograms) and is designed to put satellites into a variety of orbits.
So far this year, Russia has carried out the fifth launch out of Plesetsk Cosmodrome and the 13th overall from Russia.
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