Irtysh, also known as Soyuz‑5, is a medium-class orbital launch vehicle under development by Russia, led by the RKTs Progress and RKK Energia design organizations. It was conceived to replace the retired Zenit rocket family and other older medium-class launchers, forming a modern part of Russia’s space launch capabilities. The program is part of broader efforts to maintain domestic launch independence and reduce reliance on foreign-built rockets.

Specs
Height: Uncrewed: 61.9 m (203 ft 1 in) — Crewed: 65.9 m (216 ft 2 in)

Diameter: 4.1 m (13 ft 5 in)
Mass: 530,000 kg (1,170,000 lb)
Stages: 3
Payload to LEO: Uncrewed: 18,000 kg (40,000 lb) — Crewed: 15,500 kg (34,200 lb)

Payload to GTO: 5,000 kg (11,000 lb)

Development of Irtysh has been ongoing for several years, with engine testing and vehicle integration progressing steadily. Multiple ground firing tests of key engines have been conducted to ensure reliability, and the design has incorporated lessons from previous Soviet and Russian launch systems. The program has faced delays due to infrastructure and testing requirements, but progress continues toward its first flight.

The maiden flight of Irtysh is currently scheduled for 2026 and will likely be a test launch. The rocket is expected to launch from the Baikonur Cosmodrome in Kazakhstan, specifically from the former Zenit pad at Site 45/1, which has not been used for orbital launches since 2017. This launch is part of the Russian-Kazakh Baiterek joint project, marking the return of the site to operational status.

Photo courtesy of Roscosmos.

Site 45/1 is a rocket launch pad at the Baikonur Cosmodrome in Kazakhstan, historically built and used by the Soviet Union and later Russia for Zenit medium‑lift rocket launches. Completed in 1983, it hosted its first launch on 13 April 1985 with a Zenit‑2 test flight, and continued supporting Zenit‑2 and Zenit‑3 launches for government and commercial missions. The second pad in the complex, Site 45/2, was destroyed in an accident in 1990, leaving Site 45/1 as the sole active pad. The last launch from the site before recent developments was on 26 December 2017, when a Zenit‑3F rocket carried the Angosat‑1 satellite into orbit.

After nearly a decade without launches, Site 45/1 is slated to host the first flight of the new Soyuz‑5 (also known as Irtysh) rocket in 2026. This will be the first time the launch pad is used since 2017. Soyuz‑5 is a medium‑class Russian launch vehicle developed to replace the Zenit and expand Russia’s orbital launch capabilities, capable of lifting around 17 tonnes to low Earth orbit.

The upcoming Soyuz‑5 launch at Site 45/1 is expected to be a test/demonstration flight, marking the debut of the rocket and the pad’s return to operational status after years of inactivity. The rocket and its stages have been delivered to Baikonur, and ground preparations and testing are underway as part of the joint Russian‑Kazakh Baiterek project. Following the first flight, additional test flights and routine launches from the upgraded pad are planned.

Image credit courtesy of NASA/Bill Ingalls.