Soyuz-5 (rocket)

The Soyuz-5 is a Russian medium-lift launch vehicle developed by the Progress Rocket Space Centre, known as RKTs Progress. It was designed to replace the Ukrainian-built Zenit, whose launches ended after the start of the Russo-Ukrainian war in 2014, and it flies from Site 45, the former Zenit launch site, at the Baikonur Cosmodrome under a partnership with the government of Kazakhstan. The rocket uses a kerosene and liquid oxygen propellant mixture that the article calls kerolox. Its first stage is powered by the four-chambered RD-171MV, described as the most powerful liquid fuel engine in the world and based on the RD-170 originally built for the Energia, its second stage uses the RD-0124MS, and an optional Blok DM-03 third stage can serve geostationary missions. Soyuz-5 first launched in April 2026, and it is also meant to serve as the base of the Yenisei, a super heavy-lift launch vehicle.