The Universal Docking Module (UDM) (Russian: Универсальный стыковочный модуль), was a planned Russian docking module for the International Space Station, to be jointly built by RKK Energia and Khrunichev. The Prichal nodal addition to the Nauka laboratory, the eventual form of the FGB-2 design upon which the UDM was based, grew out of this proposal. [1]