MOSCOW (Roscosmos PR) — The Russian crewmembers of the 65th long-term expedition to the International Space Station are preparing the Pirs module for undocking from the Russian segment of the ISS. Given that the Proton-M carrier rocket launches with the Nauka module on July 21, 2021, Pirs undocking is scheduled for July 23.
Roscosmos cosmonauts Oleg Novitskiy and Pyotr Dubrov, together with the specialists from the Chief Operating Control Group of the Russian segment of the ISS (RSC Energia, part of Roscosmos) split the hydraulic circuit and docking unit control communications through the Progress MS-16 cargo vehicle, and checked the docking unit and its systems. After that, the crew took readings from all systems and assemblies of the module.
The Pirs docking module will be replaced by the new Nauka Multifunctional Laboratory Module. Pirs is to be undocked from the International Space Station by the Progress MS-16 cargo vehicle on July 23 at 13:17 UTC and sink in the Pacific Ocean in about 4 hours after undocking.
The Pirs module was launched from the Baikonur Cosmodrome on September 15, 2001 on a specialized Progress-M cargo ship, which successfully docked the module to the nadir port of the Zvezda Service Module of the ISS Russian Segment on September 17. Since then, it has been used as an additional berthing port for the Soyuz crewed and Progress cargo spacecraft, as well as an airlock for spacewalks under the Russian program.
The Pirs Docking Compartment consists of a sealed hull and features equipment, service systems and structural elements that ensure spacewalks. The outer side of the hull is covered with 1 mm thick anti-meteorite protection panels and screen-vacuum thermal insulation.
Two active and passive docking nodes are located along the longitudinal axis of Pirs. The active docking node is designed for sealed connection with the Zvezda Service Module. The passive docking node on the opposite side is designed for sealed connection with the Soyuz and Progress ships.