US/Russian Adapter

Because there are different standards for the Space Station components designed in Western countries and in Russia, a US/Russian Adapter has been built.  Formally known as the Pressurized Mating Adapter or PMA, this unit reconciles the different sizes of the opening of the Russian and American pressurized modules.  It also copes with the differences in the designs of the module connectors, allowing Russian and American components to be used on the same space station.  A unit very similar to the US/Russian Adapter has already flown on the US space shuttle permitting the shuttle to dock with the Mir space station on June 29, 1995.
