Soyuz 2.1b Launches New GLONASS-M Navigation Satellite

Russia successfully launched on Saturday, November 3, the newest GLONASS-M spacecraft for the country’s Global Navigation Satellite System (GLONASS).

The satellite, designated GLONASS-M No. 757, lifted off atop a Soyuz 2.1b booster at 11:17 p.m. Moscow time (20:17 GMT / 3:17 p.m. EST) from the Pad 4 at Site 43 of the Plesetsk Cosmodrome located in northern Russia.

The launch was overseen by the Commander of the Space Troops and Deputy Commander-in-Chief of the Aerospace Force Colonel General Alexander Golovko. Launch success was confirmed by the Russian Defense Ministry about 80 minutes after liftoff.

"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 government-owned TASS press agency quotes the Russian Defense Ministry as saying.

The pre-launch campaign for the mission commenced 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.

There were worries that the mission could be delayed due to the October 11 Soyuz-FG rocket failure. However, the accident has not affected the pre-launch operations as they were carried out in a routine mode and the date of the liftoff remained unchanged.

Powered by its RD-107A engines, the Soyuz 2.1b rocket completed a short vertical climb after blastoff. The four boosters, responsible for accelerating the launch vehicle during the initial phase of the flight, were jettisoned at approximately two minutes into the flight.

Next, 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 was 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 tasked with injecting the satellite 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 orbit, however Russia has not disclosed which one exactly it will replace.

GLONASS-M satellites, also known as Uragan-M, are the second generation of Uragan satellite designs 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, is 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 determination 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. A total of 24 satellites are required to guarantee global coverage, while 18 are necessary to cover the territory of Russia.

The Soyuz 2.1b rocket employed for Saturday’s launch is an upgraded version of the three-stage Soyuz 2 booster. The 151-foot (46.1-meter) tall launch vehicle has a total mass of 672,000 pounds (304,814 kilograms) and is designed to put satellites into a variety of orbits.

For Saturday’s mission, the Soyuz 2.1b rocket was used in a configuration with a Fregat-M third stage. This upper stage measures approximately 4.9 feet (1.5 meters) long and is 11 feet (3.35 meters) in diameter. Its S5.92 engine is designed to burn for about 18 minutes.

Saturday’s launch was the 13th flight for Russia and the fifth launch from Plesetsk in 2018.