Soyuz-5: the New Russian Rocket Debuts from Baikonur

On April 30th, at 9:00 PM Moscow time, the new Soyuz-5 lifted off from Baikonur Cosmodrome Pad 45, the same one once used by Zenit, successfully completing its first suborbital test flight.

7:00 PM GMT, April 30, 2026: The Soyuz-5 Sunkar lifts off from Baikonur's pad 45 for its maiden flight. Credit: Roscosmos — *7:00 PM GMT, April 30, 2026: The Soyuz-5 Sunkar lifts off from Baikonur’s pad 45 for its maiden flight. Credits: Roscosmos*

The first two stages operated normally, and the payload simulator followed the planned trajectory until splashdown in the Pacific Ocean. For Roscosmos, this was far more than just a successful test.

From Zenit to Soyuz-5

To truly understand what Soyuz-5 represents, we need to go back forty years, to Zenit, one of the most advanced Soviet rockets ever built.

Designed in Ukraine but equipped with Russian engines, Zenit was considered the natural bridge between the Soyuz and Proton launch vehicles. A modern launcher, relatively “clean” thanks to the use of kerosene and liquid oxygen, reliable enough to be chosen even for the Sea Launch program, the ocean launches from the Odyssey platform.

*One of the launches from the Sea Launch Odyssey marine platform. Credits: Roscosmos*

Then came 1991, and later, 2014. As tensions between Russia and Ukraine escalated into open conflict and eventually full-scale war, Moscow suddenly found itself without its most efficient medium-class launcher.

From that moment came the need to create a completely Russian successor.
The result is precisely Soyuz-5, also known by the names Irtysh or Sunkar.
Calling it “a new rocket,” however, would be reductive.
Soyuz-5 is rather a modern reinterpretation of Zenit: the same design philosophy, but with updated components and significantly greater power.

The Soyuz-5 Sunkar's RD-171MV quad-chamber engine. In the background is the "birdcage," the crew's wing of the mast. Credit: Roscosmos — *The Soyuz-5 Sunkar’s RD-171MV quad-chamber engine. In the background is the “birdcage,” the crew’s wing of the mast. Credits: Roscosmos*

The heart of the rocket: the gigantic RD-171MV

The heart of the project is undoubtedly the RD-171MV, installed in the first stage.
And here we enter an almost mythological territory of Soviet space propulsion engineering.

The RD-171MV is derived directly from the RD-170 developed for the colossal Energia launcher. It is a four-chamber engine powered by RP-1 synthetic kerosene and liquid oxygen, capable of producing more than 8 MN of thrust in vacuum, a figure that during recent tests reached approximately 8.06 MN. For comparison, a Starship Raptor produces around 2.3 MN of vacuum thrust, while a Falcon 9 Merlin 1D+ reaches about 0.93 MN. This means that Soyuz-5 flies thanks to one of the most powerful engines ever to enter operational service.

And this is precisely one of the most fascinating aspects of contemporary Russian cosmonautics: while much of the world focuses on reusability and new methane cycles, Russia continues refining an engineering school born in the Soviet era and still incredibly competitive in terms of pure propulsion efficiency.

A More Modern and Efficient Second Stage

The second stage also represents an evolution compared to the original Zenit.
Instead of the old RD-120, we now find the RD-0124MS, an evolution of the engine already used on Soyuz-2.1b.

A more efficient, more modern propulsion system designed to improve the launcher’s overall performance. The final result is a launch vehicle capable of carrying about 17 tons into low Earth orbit, practically almost double the capacity of traditional Soyuz rockets

The Soyuz-5 Sunkar rolls out of the assembly complex (MIK) named after the joint Russian-Kazakh Baiterek program. Credit: Roscosmos — *The Soyuz-5 Sunkar rolls out of the assembly complex (MIK) named after the joint Russian-Kazakh Baiterek program. Credits: Roscosmos*

Baiterek: Kazakhstan’s Space Future

But Soyuz-5 is not important only for technical reasons. Behind its development lies the Baiterek program, probably one of the most significant political-industrial projects in contemporary Central Asia.

After the collapse of the USSR, Kazakhstan found itself the owner of the Baikonur Cosmodrome, while Russia remained its main user. For more than thirty years, the most famous spaceport on the planet survived in a sort of delicate balance: Kazakh territory, Russian management.

With Baiterek, the situation changes. The project includes the modernization of the historic Zenit infrastructure and the direct involvement of Kazakhstan in the development of the new launch complex. No longer simply “hosting” Baikonur, but truly participating in access to space. After the April 30 launch, Kazakh authorities openly spoke of a new era for the nation’s cosmonautics.

The Possible Future with the Oryol Capsule

Another detail could make this launcher historic. Roscosmos plans to use Soyuz-5 for the future crewed Oryol spacecraft, intended to progressively replace the current Soyuz capsules. If this plan materializes, for the first time in more than half a century, Russian cosmonauts could leave Earth not aboard a direct derivative of Korolev’s R-7, but on a completely different launcher. And this is where Soyuz-5 takes on an almost symbolic value.

*The Soyuz-5 Sunkar on Pad 45 of the Baiterek complex in Baikonur. A year ago, work had not yet begun. Credit: Roscosmos*

Naturally, many uncertainties remain. The launch market has changed radically, Falcon 9 competition is enormous, and Soyuz-5 arrives in an era in which reusability is redefining the economics of spaceflight.

However, it would be a mistake to dismiss it as “just another Russian rocket.”
Because on April 30, 2026, what lifted off from Baikonur was not simply a launch vehicle. It was the idea that post-Soviet cosmonautics might still have an independent future.