The Mir Docking Module, formally known as the Stykovochnyy Otsek (SO; Russian: стыковочный отсек, lit.

When the Shuttle-Mir programme began, engineers realised that in order to enable US space shuttles to dock to Mir, the Kristall module would have to be relocated to the forward port of the core module and back to its own lateral port each time a shuttle docked, a process which was not only time consuming but would also be entirely reliant on Kristall's Lyappa arm, which, should it fail, would prevent any further shuttle missions to the station.

[1] Discussions on providing a docking module for the Shuttle-Mir programme began in May 1993 and approval was granted on 1 November, with the draft plan being developed by December.

[5] Development of the simplified module was given priority over the more complex Mir-2 type SO-1, and the flight model, the first to make use of NASA's new Space Station Processing Facility, was delivered to Kennedy Space Center on 7 June 1995 alongside the new solar arrays which were to be launched with it.

[8] MEEP also fulfilled the need to examine the occurrence and effects of man-made debris and natural micrometeoroids through capture and impact studies.