Soyuz-2-1v rocket launches military payload

On March 29, 2023, Russian military personnel in Plesetsk performed a successful launch of Soyuz-2-1v vehicle with a classified payload, according to the nation's department of defense


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The EO MKA No. 4 mission at a glance:

Spacecraft designation EO MKA No. 4, Kosmos-2568
Launch date and time 2023 March 29, 22:57:02 Moscow Time (19:57 UTC)
Launch vehicle

Soyuz-2-1v (14A15)

Launch Site Plesetsk, Launch complex 17P32-S4, Site 43

Around March 14, 2023, rumors on the Russian-language forums reported preparations for another launch from Plesetsk within couple of days. According to some posters, a Soyuz-2-1v rocket was expected to launch EO MKA No. 4 experimental satellite, apparently similar to a previous such spacecraft launched in 2021. By March 16, Russian authorities issued a warning to air traffic in the Arctic region, indicating a launch around 07:00 UTC on March 23, 2023.

According to the warnings to air and and sea traffic issued by the Russian authorities, the launch from Plesetsk was planned between 20:00 and 21:00 UTC (23:00-24:00 Moscow Time, 4-5 p.m. EDT) on March 29, 2023.


The mission lifted off on March 29, 2023, at 22:57:02 Moscow Time.

Emulating a similar earlier mission, the rocket likely headed almost exactly north, under the combined propulsion of a single NK-33 main engine and the four thrusters of the RD-0110 steering engine. Lacking the four strap-on boosters of its predecessors in the Soyuz family of rockets, Soyuz-2-1v relied solely on a modified core booster as its first stage.

Following the first-stage ascent, the second stage took over the powered flight around two minutes into the flight. It fired its four-chamber engine moments before the separation of the first stage, thanks to a lattice structure connecting the two boosters, which allows the free flow of the exhaust from the nozzles above. Right after the separation of the first stage, the tail section of the second stage split into three segments and fell away.

Both, the first stage and the fragments of the tail section were expected to splash down in the Barents Sea, north of Murmansk.

As the second stage continued its burn, the payload fairing protecting the satellite split in two halves and also separated. Its fragments were to fall into the Arctic Ocean, south of the Spitsbergen Archipelago.

Around the time of the reentry of the second such satellite in May 2022, a post on the Novosti Kosmonavtiki forum claimed that Kosmos-2555 and Kosmos-2551 had served as targets for Russia's Peresvet anti-satellite laser system. Both satellites were not intended to manuever and functioned as planned. The reentry of Kosmos-2555 was preceded by a statement from Deputy Prime Minister Yuri Borisov about Russia's satellite-blinding laser.

After the successful launch on March 29, 2023, the new satellite received official designation Kosmos-2568.

The US Space Force quicklly published orbital parameters for two objects associated with the launch, likely representing the payload and the upper stage:

Orbital period
91.27 minutes
96.46 degrees
345 kilometers
329 kilometers
91.23 minutes
96.47 degrees
344 kilometers
326 kilometers


In the following weeks, the satellite was seen steadily losing altitude without any sign of orbital maneuevers:

Orbital period
2023 April 4
91.3 minutes
96.5 degrees
335.7 kilometers
350.6 kilometers
2023 April 9
91.2 minutes
96.5 degrees
334.3 kilometers
348.9 kilometers
2023 April 14
91.2 minutes
96.5 degrees
332.0 kilometers
347.9 kilometers
2023 April 19
91.1 minutes
96.5 degrees
329.7 kilometers
346.2 kilometers

However, in late June and early July 2023, Kosmos-2568 showed first signs of orbital maneuvering, something that have never been noticed happening to his three presumed predecessors – Kosmos-2551, Kosmos-2555 and Kosmos-2560. Starting around Aug. 9, 2023, Kosmos-2568 appeared to perform small orbit-raising maneuvers, counteracting natural orbital decay. The apparent orbit boosts continued until around Oct. 6, 2023, when the uninterrupted descent of the spacecraft had resumed.

However, after the average altitude of the satellite fell by around four kilometers by Oct. 11, 2023, small orbit-raising maneuvers seemingly started again. Interestingly, Kosmos-2568 appeared to be entering orbit, which made it possible periodic flybys directly below Kosmos-2561 at a distance of around 150 kilometers. The latter satellite also resumed maneuvers in the middle of September 2023, after flying passively since the beginning of April 2023.


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Page author: Anatoly Zak; Last update: December 20, 2023

Page editor: Alain Chabot; Last edit: March 29, 2018

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A Soyuz-2-1v rocket leaves the assembly building in Plesetsk in March 2023. Credit: Russian Ministry of Defense


A Soyuz-2-1v rocket rolls out to the launch pad in Plesetsk in March 2023. Credit: Russian Ministry of Defense


Soyuz-2-1v lifts off on March 29, 2023. Credit: Russian Ministry of Defense