On Friday, a Soyuz booster and a Fregat upper stage put a missile warning satellite for the Russian military into orbit.
Launched from the Plesetsk Cosmodrome in Russia’s far north, the Soyuz-2.1ba rocket lifted off at 0731 GMT (0331 EDT; 10:31 Moscow time) on Friday and headed southeast.
A statement from the Russian Defense Ministry did not identify the payload, but information on the mission’s trajectory published in warning notices to pilots and sailors suggests the satellite was likely the fourth alert satellite. EKS missiles, or Tundra, for the Russian army.
The Defense Ministry said the spacecraft had been launched into the targeted orbit and ground controllers had established stable communications with the new satellite. The spacecraft will receive the Kosmos 2546 designation, in accordance with the Russian government’s naming scheme for military satellites.
The satellite was to be deployed in an elliptical orbit between approximately 1,000 miles and 24,000 miles (1,600 kilometers and nearly 39,000 kilometers) from the Earth’s surface. EKS, or Tundra, satellites fly in orbits tilted approximately 63.8 degrees from the equator.
Russia launched four EKS-class early warning satellites launched on Soyuz / Fregat rockets in November 2015, May 2017 and September 2019. The new generation of EKS satellites replace the Russian series of Oko missile warning spacecraft , the last of which was launched in 2012.
The flight profile for Friday’s launch included the separation of the four kerosene-powered boosters from the Soyuz rocket approximately two minutes after the start of the mission, followed by the dropping of the payload fairing and the rocket’s center stage. . A third stage powered by an RD-0124 engine then ignited, followed by the deployment of a Fregat upper stage on a suborbital trajectory approximately nine minutes after the start of the mission.
The Fregat upper stage fired several times to place its satellite payload in the target orbit, and the spacecraft separated from the Fregat space tug several hours after takeoff.
Russia uses missile warning satellites, as well as ground-based radars, to track missiles approaching the country’s territory. The Molniya-like orbits used by EKS satellites give the spacecraft’s thermal infrared sensors long views of the northern hemisphere on every 12-hour loop around the Earth.
The orbits allow satellites to detect missile launches from North America and detect incoming missiles that threaten Russian territory.
Friday’s mission was the seventh flight of a Soyuz rocket so far this year and the third launch from Plesetsk Cosmodrome in 2020.
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