EO MKA-4 | Soyuz 2.1v

Lift Off Time
March 29, 2023 – 19:00:00 UTC | 22:00:00 MSK
Mission Name
Launch Provider
(What rocket company will launch it?)
Russian Space Forces
(Who is paying for this?)
Russian Ministry of Defense
Soyuz 2.1v
Launch Location
Site 43, Pad 4, Plesetsk Cosmodrome, Russia
Payload mass
~150 kg (~330 lb)
Where will the satellite go?
Sun-Synchronous Orbit (SSO) ~300 km altitude, ~96.5° inclination
Will they attempt to recover the first stage?
No, this is not a capability of Soyuz
Where will the first stage land?
It will crash into the Barents Sea south of Svalbard (Norway)
Will they attempt to recover the fairings?
No, this is not a capability of Soyuz
Are these fairings new?
This is the:
1st launch of Soyuz 2.1v in 2023
– 2nd launch from the Plesetsk cosmodrome in 2023
10th launch of Soyuz 2.1v
50th orbital launch attempt of 2023
Where to watch
If a live stream is available, it will be provided here

What Does All This Mean?

Russia is launching a small military satellite, known as EO MKA-4, to a Sun-Synchronous Orbit onboard the tenth orbital launch of a Soyuz 2.1v rocket. Soyuz 2.1v is notably different from other variants of Soyuz/R7, since it has no side boosters. This mission marks the first launch of the Soyuz 2.1v rocket of this year.

EO MKA-No.4 Satellite

Not much is known about this payload, due to its military and secret purpose. The EMKA series of satellites are thought to be optical reconnaissance spacecraft. The first EMKA satellite, designated as Kosmos 2525, launched on a Soyuz 2-1v rocket back in March 2018.

The second satellite in the series, known as Kosmos 2551, reached orbit successfully, but apparently showed no signs of life after this. It is thought to have fallen out of orbit in October 2021.

A third EMKA satellite, known as Kosmos 2555, was launched on the inaugural orbital flight of Angara 1.2, in April 2022. This vehicle appeared to have no operational function after separating from its payload adapter, and fell out of orbit in May 2022.

Later in 2022, another EMKA satellite was launched on another Angara 1.2 rocket. This was designated Kosmos 2560 after its successful deployment.

The prime contractor for building the satellite is NPP Vniiem. The imaging sensor has been constructed by OAO Peleng which is a company located in Belarus.

The “E” in “EMKA” is understood to represent the word “experimental”. This satellite is known as “EO MKA” as opposed to “EMKA”. It is not yet clear what this change in terminology represents.

What is Soyuz 2.1v?

ROSCOSMOS’s Soyuz is a multi-use medium-lift launch vehicle that was introduced in far 1966 and since then has been the workhorse of the Soviet/Russian space program. It is capable to launch civilian and military satellites, as well as cargo and crewed missions to the ISS. Over the decades, several variants of the Soyuz rocket have been developed. Soyuz 2.1v is one of its latest iterations that belongs to the Soyuz-2 rocket family and is based on the Soyuz 2.1b.

However, the Soyuz 2.1v drastically differs from other family members, the Soyuz 2.1a and Soyuz 2.1b. Unlike them, the Soyuz 2.1v is a small-lift launch vehicle that lacks the four strap-on boosters. Consequently, this rocket does not feature the “Korolev cross”, a pattern that happens when the four side boosters separate from the core stage.

Soyuz 2.1v on the launch pad
The Soyuz 2.1v rocket on the launch pad. (Credit: Ministry of Defense of the Russian Federation)

The rocket consists of two stages, both of them are expendable. Moreover, it can feature the Volga upper stage. Soyuz 2.1v is about 44 meters (144 ft) in height and 3 meters (9 ft) in diameter. The vehicle’s total lift-off mass is approximately 160,000 kg (365,967 lb). The rocket’s payload lift capacity to low-Earth orbit (LEO) is between 2,800 and 3,300 kg depending on the launch site. Further, its payload lift capacity to SSO is between 1,200 and 1,400 kg.


First StageSecond Stage
Engine 1 NK-33A + 1 RD-0110R1 RD-0124
Total Thrust 1,535 kN (345,082 lbf),
sea level
1,714 kN (385,323 lbf),
294 kN (66,094 lbf),
Specific Impulse (ISP)297 s, NK-33A, sea level
261 s, RD-0110R, sea level
359 s, vacuum

First Stage

The first stage of the Soyuz 2.1v rocket is powered by a single-chamber NK-33 engine and a steering RD-0110R engine. They are capable of producing a thrust of 1,535 kN at sea level and 1,714 kN in a vacuum. Originally, the NK-33 engine was designed and built for the N-1 rocket for the Soviet lunar program, by the Kuznetsov Design Bureau. It runs on kerosene and liquid oxygen (LOx) and works in the staged combustion cycle. 

Second Stage

The second stage of the Soyuz 2.1v is identical to the third stage of the Soyuz 2.1b. It is powered by a single RD-0124 engine that runs on kerosene and LOx and has four combustion chambers. This engine produces a thrust of 294 kN in a vacuum, with an ISP of 359 s.

One interesting thing about the RD-0124 engine on this stage is that it starts its ignition sequence prior to stage separation. This process is called “hot fire staging” and is possible thanks to the open interstage that has a lattice structure.

Rocket-motor-RD-0124б Soyuz 2.1b
RD-0124 motor at Salon-du-Bourget 2013. (Credit: Pline)

Rocket section adapted from Mariia Kiseleva.

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