The Soviets added the Kristall ("Crystal") module to Mir in June 1990. The module contains experiment space inside for biological and materials science experiments. it also hosts solar panels used to generate power for Mir.
The module also comes equipped with a special "androgynous docking mechanism" at the far end of the module. The docking port was designed to accomodate the Buran space shuttle the Soviet Union developed, but was never used for this purpose as the Buran was mothballed after a single unmanned test flight. It was used for the first Shuttle/Mir docking mission, STS-71, in June 1995. Later shuttle docking missions now use the docking module attached to the docking port in the second shuttle docking.
| Length: | 13.7 m (45.2 ft.) |
| Mass: | 19,650 kg (43,230 lbs.) |
| Max. Diameter | 4.3 m (14.2 ft.) |
| Volume: | 60.8 m^3 (2180 cu. ft.) |