Mir Core Module

The Mir Core Module, also known as the Base Block or DOS-7, was a module of the Mir space station. It was the first module to be launched and operated in low Earth orbit from 1986 until its de-orbiting in 2001. The module was launched on a Proton-K rocket on February 20th, 1986.

A spare of this module, originally designed for Mir-2, later became the Zvezda module used on the International Space Station.