TASS reports that Russia and Kazakhstan have agreed to construct a new launch complex for the Soyuz-5 and Soyuz-6 rockets at the latter’s Baikonur Cosmodrome. Kazakhstan will be responsible for ground infrastructure while Russia will develop the new launch vehicles.
The construction will take place at the Baiterek launch facility that previously was to be modernized for launching Zenit boosters. Zenit is a rocket largely built in Ukraine but had elements supplied in Russia. Cooperation on the Zenit program ended after Russia annexed Ukraine’s Crimea region and invaded the country.
Being developed by JSC Progress, the Soyuz-5 booster is designed to replace the Zenit-2 and Proton-M booster and serve as the base for a super heavy-lift launcher that will match the capabilities of the retired Energia rocket. Soyuz-5 will be capable of lifting satellites weighting 18 metric tons or crewed spacecraft weighing 15.5 metric tons to low Earth orbit.
There isn’t much public information available on the Soyuz-6 rocket. The new booster will apparently be a shortened version of the Soyuz-5 booster.