MLM-U (Mnogozelewoi Laboratorny Modul - Usovershenstvovanny, Multipurpose Laboratory Module - Upgrade) is a multipurpose module of the russian segment of the International space station ISS. MLM is built using the module, which was once slated to become the UDM (Universal Docking Module), which was in turn modified from the FGB-2 module, which was the back up of the central FGB module.
The MLM module will accommodate both service systems for the Russian segment of the ISS and scientific payloads. The European-built ERA manipulator and the DMS-R multifunction computer will also be installed onboard.
The effort to build FGB 2 as a back-up for FGB 1 dates back to 1995 when the top managers of the Khrunichev Space Center decided to engage in this project using the Center's budget, almost in parallel with creating the Functional Cargo Module Zarya, the first element of the ISS. In compliance with Rosaviacosmos Decision dated 16 February 2004, on Implementation of abbreviated ISS configuration as well as the Federal Space Agency Decision dated 20 July 2004, on Multipurpose Lab Module (MLM) implementation process using the FGB 2 backlog, the MLM was included in the Russian Segment Configuration on the nadir port of Zarya Module.
The target date for the completion of MLM as defined in the MLM Program Schedule was late 2007. At present, the MLM's detailed profile has been finalized based on streamlined design parameters proceeding from the need to reduce the cost and time to be spent on building the Russian Segment of the ISS while making the most of the hardware backlog and potential investment from foreign partners and commercial customers. Following final definition of the MLM Design Specification within the abbreviated Russian Segment configuration of the ISS, it will take two years to implement modifications. As per the ISS RS abbreviated configuration the FGB 2-based MLM is to support further ISS RS deployment providing docking ports to transportation vehicles and research modules as well as accommodating payloads, providing stowage capability, etc.
The MLM should be capable of supporting commercial projects to the degree possible so as to outsource off-budget funding including investments to be used to complete and commission the module.
Following requirements were set for the FGB 2-based MLM as derived from the input data:
Functions to Support Russian Segment:
Originally scheduled for 2009, the launch of the MLM module has been delayed several times. In 2013 a leak in the propulsion system was found, postponing the launch to 2015, then to mid 2017. In June 2016, it was again delayed by six months to December 2017. At the same time, the designation was changed to MLM-U, hinting at upgrades being made to the module, possibly to enable it to act as the core of a separated free-flying Russian segment. Further issues delayed it to November 2019. Contamination in the propulsion system was discovered, and in March 2019 it was decided to replace the contaminated tanks of the propulsion system by new ones built by Lavochkin based on their Fregat stage. Launch has now slipped to May 2021.
|Type / Application:||Space Station module|
|Power:||2 deployable solar arrays, batteries|
|Orbit:||400 km × 400 km, 51.6° (typical)|
|MLM-U (Nauka, ex MLM ex UDM ex FGB 2)||-||2021||Ba LC-200/39||Proton-M|