Russia's Plan To Spin Off a New Space Station From the ISS, Popular Mechanics
"According to RKK Energia, the prime Russian contractor on the ISS, the new outpost would begin with the separation of the Nauka from the rest of the old station in mid-2020s. By that time, Nauka should have two even newer modules in tow. One would be the so-called Node Module, a tinker-toy-like component that could connect to six other modules, crew ships, cargo tankers, structural elements, you name it. The Node Module is already in RKK Energia's garage and ready to go within a few months after the Nauka. Next would be the new Science and Power Module (NEM) which, as it name implies, will finally give cosmonauts a state-of-the-art science lab and a pair of large solar arrays, making the Russian segment fully independent from the rest of the ISS in terms of power, communications, and other resources."