Nauka, also known as the Multipurpose Laboratory Module-Upgrade or simply Multipurpose Laboratory Module (MLM), is a module of the International Space Station (ISS). The MLM-U is funded by Roscosmos. In the original ISS plans, Nauka was to use the location of the Docking and Storage Module (DSM). Later, the DSM was replaced by the Rassvet module and Nauka was moved from Zarya's nadir port to Zvezda's nadir port.

Zarya, also known as the Functional Cargo Block or FGB, is the first module of the International Space Station to have been launched. The FGB provided electrical power, storage, propulsion, and guidance to the ISS during the initial stage of assembly. With the launch and assembly in orbit of other modules with more specialized functionality, as of August 2021 it is primarily used for storage, both inside the pressurized section and in the externally mounted fuel tanks. The Zarya is a descendant of the TKS spacecraft designed for the Soviet Salyut program. The name Zarya ("Dawn") was given to the FGB because it signified the dawn of a new era of international cooperation in space. Although it was built by a Russian company, it is owned by the United States.