Russia Launches new useless ISS docking module…..
https://www.nasaspaceflight.com/2021/11/prichal-launch/
Russia launches new docking node to space station
Rgoscosmos launched a new docking node module to the International Space Station (ISS) on Wednesday, November 24 at 13:06 UTC / 8:06 am EST.
Launching from the Baikonur Cosmodrome in Kazakhstan, the module will add additional docking ports to the Russian Segment of the station to provide options for future expansion but is the final Russian model planned for the outpost.
The original design for the Russian Segment of the ISS called for a Universal Docking Module (UDM) to expand the Russian Segment’s available docking ports for the addition of future modules. This module was canceled early in the ISS program due to budget issues.
However, out of the UDM concept grew a new proposal for a Nodal Module (NM), which would provide the Russian Segment with expansion options since all of its docking ports were either in use or reserved for visiting spacecraft.
The node, named Prichal (“pier”), marks a departure from the previous concept of Russian station design, which typically included a core module (which, in the case of ISS, is Zvezda) with an attached spherical docking compartment to which all other modules are docked.
The problem with this design is that it makes the core module an irreplaceable part of the station, as all the other modules would have to be undocked from the core module for the core to be replaced — something which is not technically feasible once all modules have been integrated.
This means that as the core module ages and its systems begin to fail, there is no option but to build a brand-new station, even though the other modules may be newer and perfectly functioning.
The Node Module concept essentially separates the spherical docking compartment from the core module and makes it into a standalone element. All station modules would then dock to the Node Module, the idea being that each module is then replaceable without having to undock them all.
In this sense, Prichal is essentially the Russian equivalent of the Node modules found on the US segment of the station.
It was originally planned that two Science & Power Modules (NEMs) would be docked to Prichal as part of an expansion of the Russian Segment, with a view to then one day separate from the ISS into a free-flying station.
However, in April 2021, Roscosmos announced that the NEMs are no longer planned for the ISS and will instead form part of a new independent Russian space station for which a new Node Module would be built.
Therefore, while Prichal is an interesting module in many ways, it is already essentially a module without a purpose as it does not, in itself, add any additional capabilities to the ISS over what the station already has…..