Nodal module

Uzlovoy Module ″Prichal″ also known as UM (Russian: Узловой Модуль ″Причал″, Nodal Module Berth) is a Russian spacecraft which will form part of the International Space Station, and later the proposed Russian OPSEK space station. Approved in 2011 and scheduled for launch in 2018, it is designed to connect modules of the future OPSEK space station.

The nodal module is intended to serve as the only permanent element of OPSEK, a Russian space station intended to support deep space manned exploration missions to Mars, possibly the Moon, and Saturn. Other OPSEK modules will be replaced as they reach the end of their useful life, whilst the Uzlovoy Module will be refurbished on orbit for an extended period.

The module has six hybrid docking ports. One port is equipped with an active docking port to allow docking with the space station, while the remaining five ports are passive, enabling other spacecraft to dock with the module. The Nadir, or earth-facing, port will support automated transfer of propellants between docked Russian spacecraft and the ROS in both directions, and automated docking of manned and unmanned spacecraft using the Kurs system. The docking compartment has an internal volume of 14 cubic metres.

In the current plans the Zvezda nadir location is scheduled to be used by the Nauka module. Additionally the SO2 was put back in the plans, but relocated to Zvezda zenith location (the location for the cancelled SPP).

In the mid-2000s, RKK Energia, the manufacturer of the ROS components, again added the UM to the future configuration of the ISS. The proposal is to execute a similar to the original ISS plan with the addition of a Nodal Module (significant modification of the UDM design - to increase the number of docking ports from 4 to 6 and to take into account its location at MLM nadir - at the same time with reducing its weight from 20t to 4t and removing the additional life-support system) and two additional science/energy modules to the segment around 2013-2015. Despite its small size, this four-ton, ball-shaped module could play an extremely important role in the Russian space program.

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