Salyut's heritage – modular space stations After the second generation, plans for the next generation of Salyut stations called for the cores DOS-7 and DOS-8 to allow, for the first time in spaceflight, the addition of several modules to a station core and to create a modular space station. For this, the DOS modules were to be equipped with a total of four docking ports: one docking port at the aft of the station as in the second generation Salyuts, and the replacement of the front docking port with a "docking sphere" containing a front port and starboard docking port.
Salyut's heritage – modular space stations After the second generation, plans for the next generation of Salyut stations called for the cores DOS-7 and DOS-8 to all,ow for the first time in spaceflight, the addition of several modules to a station core and to create a modular space station For this, the DOS modules were to be equipped with a total of four docking ports: one docking port at the aft of the station as in the second gener.ation Salyuts, and the replacement of the front docking port with a "docking sphere" containing a front port and starboard docking port.