''Pirs'' ''('', meaning "
pier
A pier is a raised structure that rises above a body of water and usually juts out from its shore, typically supported by piling, piles or column, pillars, and provides above-water access to offshore areas. Frequent pier uses include fishing, b ...
") – also called Stykovochny Otsek 1 (SO-1; , "
docking module") and DC-1 (Docking Compartment 1) – was a Russian module on the
International Space Station
The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...
(ISS). ''Pirs'' was launched on 14 September 2001, and was located on the ''
Zvezda'' module of the station. It provided the ISS with one
docking port for
Soyuz
Soyuz is a transliteration of the Cyrillic text Союз (Russian language, Russian and Ukrainian language, Ukrainian, 'Union'). It can refer to any union, such as a trade union (''profsoyuz'') or the Soviet Union, Union of Soviet Socialist Republi ...
and
Progress
Progress is movement towards a perceived refined, improved, or otherwise desired state. It is central to the philosophy of progressivism, which interprets progress as the set of advancements in technology, science, and social organization effic ...
spacecraft, and allowed egress and ingress for
spacewalks by
cosmonauts
An astronaut (from the Ancient Greek (), meaning 'star', and (), meaning 'sailor') is a person trained, equipped, and deployed by a human spaceflight program to serve as a commander or crew member of a spacecraft. Although generally reserve ...
using Russian
Orlan space suit
270px, Cosmonaut Maksim Surayev next to two Orlan-MK models on the International Space Station
image:Sharipov one.jpg, 270px, Cosmonaut Salizhan Sharipov, next to the Orlan-M spacesuit
The Orlan space suit () is a series of semi-rigid one-piece ...
s. ''Pirs'' was docked to ''Zvezda'' for almost 20 years, until 26 July 2021, when it was decommissioned and undocked by
Progress MS-16 to make way for the new ''
Nauka'' module.
Poisk module
A second docking compartment, Stykovochniy Otsek 2 (SO-2), was planned with the same design. However, when the Russian segment of the ISS was redesigned in 2001, the new design no longer included the SO-2, and its construction was canceled.
After another change of plans the SO-2 module finally evolved into the
''Poisk'' module, which was added to the ISS in 2009.
Design and construction

The ''Pirs'' docking compartment had two primary functions: to provide a docking port for visiting Soyuz and Progress spacecraft and to serve as an airlock for Russian EVAs. The docking port could accommodate one
Soyuz-MS or one
Progress-MS spacecraft. Visiting spacecraft could deliver people and cargo to and from the space station. In addition, the Docking Compartment could transfer fuel from the fuel tanks of a docked Progress resupply vehicle to either the Zvezda Service Module’s Integrated Propulsion System or the
Zarya Functional Cargo Block. It could also transfer propellant from ''Zvezda'' and ''Zarya'' to the propulsion system of docked vehicles — Soyuz and Progress. The two
airlock
An airlock is a room or compartment which permits passage between environments of differing atmospheric pressure or composition, while minimizing the changing of pressure or composition between the differing environments.
An airlock consist ...
s were designed to accommodate
spacewalk
Extravehicular activity (EVA) is any activity done by an astronaut in outer space outside a spacecraft. In the absence of a breathable atmosphere of Earth, Earthlike atmosphere, the astronaut is completely reliant on a space suit for environme ...
ing
cosmonauts
An astronaut (from the Ancient Greek (), meaning 'star', and (), meaning 'sailor') is a person trained, equipped, and deployed by a human spaceflight program to serve as a commander or crew member of a spacecraft. Although generally reserve ...
wearing
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
n
Orlan-M spacesuit
A space suit (or spacesuit) is an environmental suit used for protection from the harsh Space environment, environment of outer space, mainly from its Vacuum (outer space), vacuum as a highly specialized pressure suit, but also its temperatu ...
s. The ''Pirs'' docking compartment was manufactured by
RKK Energia. The Docking Compartment was similar to the
Mir Docking Module used on the earlier
Mir
''Mir'' (, ; ) was a space station operated in low Earth orbit from 1986 to 2001, first by the Soviet Union and later by the Russia, Russian Federation. ''Mir'' was the first modular space station and was assembled in orbit from 1986 to ...
space station. The docking compartment's planned lifetime as part of the station was five years.
Launch
''Pirs'' was launched on 14 September 2001, as ISS Assembly Mission 4R, on a Russian
Soyuz-U
Soyuz-U ( GRAU index: 11A511U) was a Soviet and later Russian expendable medium-lift launch vehicle designed by the TsSKB design bureau and constructed at the Progress factory in Samara, Russia. The ''U'' designation stands for ''unified' ...
launch vehicle, using a modified
Progress spacecraft
The Progress () is a Russian expendable cargo spacecraft. Originally developed for the Soviet space program and derived from the crewed Soyuz spacecraft, Progress has been instrumental in maintaining long-duration space missions by providing ...
,
Progress DC-1, as an upper stage. The ''Pirs'' Docking Compartment was attached to the
nadir
The nadir is the direction pointing directly ''below'' a particular location; that is, it is one of two vertical directions at a specified location, orthogonal to a horizontal flat surface.
The direction opposite of the nadir is the zenith.
Et ...
(bottom, Earth-facing) port of the ''
Zvezda'' service module.
Docking

''Pirs'' docked to the International Space Station on 17 September 2001, at 01:05 UTC, and was configured during three spacewalks by the
Expedition 3 crew. Two
''Strela'' cargo cranes were later added by the
STS-96
STS-96 was a Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle '' Discovery'', and the first shuttle flight to dock at the International Space Station. It was Discovery's 26th flight. The shuttle carried the S ...
and
STS-101
STS-101 was a Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle '' Atlantis''. The mission was a 10-day mission conducted between 19 May 2000 and 29 May 2000. The mission was designated 2A.2a and was a resuppl ...
missions, carried up on
Integrated Cargo Carriers and installed during EVAs.
Airlock specifications
* Length:
* Diameter:
* Weight:
* Volume:
Docking location at the ISS
Undocking and disposal
On 14 July 2021, Roskosmos announced that members of the 65th expedition aboard the ISS, were preparing the ''Pirs'' module for its departure on 23 July.
The ''Pirs'' module supported 52 spacewalks and served as a docking port for Russian Soyuz and Progress spacecraft ferrying crew and cargo to and from the space station.
After nearly 20 years at the International Space Station, ISS, the ''Pirs'' Docking Compartment, SO1, undocked from the nadir (Earth-facing) port of the Zvezda Service Module, SM, on 26 July 2021, at 13:55 Moscow Time (6:55 a.m. EDT) in the joint stack with the Progress MS-16 cargo ship. At the time, the spacecraft was orbiting the Earth over Eastern China and within communications range of Russian ground stations.
Within four minutes (13:59:00 Moscow Time, according to schedule), Progress MS-16 performed a short separation burn to increase distance from the ISS. The deorbiting maneuver was planned within around three hours aiming at the reentry of the ''Pirs''/Progress stack over the Pacific.
Progress MS-16 initiated braking maneuver as planned at 17:01 Moscow Time (10:01 a.m. EDT) and after a 1,057-second (17.6-minute) burn, the module/cargo ship duo reentered the dense atmosphere at 17:42 Moscow Time (10:42 a.m. EDT).
According to NASA, the ''Pirs'' Docking Compartment spent 19 years, 313 days 9 hours 50 minutes and 45 seconds at the station and 19 years 315 days 15 hours 10 minutes and 47 seconds in flight.
Gallery
Outside
File:Pirs assembly.jpg, ''Pirs'' under construction at Energia in Moscow.
File:Progress M-SO1.jpg, Progress DC-1 with the ''Pirs'' module seen from the International Space Station during docking.
File:ISS-36 EVA-1 e Alexander Misurkin.jpg, Cosmonaut Alexander Misurkin (top center), participates in a session of extravehicular activity (EVA) near ''Pirs'' module.
File:Pirs March 2009.jpg, Image of the ''Pirs'' taken during a March 2009 EVA.
Inside
File:ISS-37 Oleg Kotov works with a Russian Orlan spacesuit in the Pirs module.jpg, Cosmonaut Oleg Kotov works with a Russian Orlan spacesuit in the ''Pirs'' Docking Compartment.
File:Main pirs interior.jpg, Gennady Padalka
Gennady Ivanovich Padalka (; born 21 June 1958 in Krasnodar, Soviet Union) is a Russian Air Force officer and Roscosmos cosmonaut. Padalka is the only person to have served as commander of the International Space Station (ISS) four times. He previ ...
(left) and astronaut Michael Fincke pose with their Orlan spacesuits.
File:ISS-30 Oleg Kononenko in the Pirs Module with Progress M-13M and the Chibis-M satellite.jpg, Oleg Kononenko is pictured near a hatch in the ''Pirs'' Docking Compartment.
Undocking
File:Progress MS-16 docked to the ISS (1).jpg, Progress MS-16 docked to the ISS. The one who undocked Pirs.
File:Progress MS-16 docked to the ISS (2) before the removal of Pirs.jpg, Progress MS-16 docked to the ISS before the removal of Pirs
File:ISS-65 Pirs docking compartment separates from the Space Station.jpg, ISS-65 Pirs docking compartment separates from the Space Station
File:ISS-65 Pirs docking compartment separates from the Space Station.webm, ISS-65 Pirs docking compartment separates from the Space Station
File:ISS_and_Progress_MS-16_with_Pirs_module.jpg, Tracks of the ISS and Progress MS-16 with the ''Pirs'' module on July 26, 2021, after undocking
References
External links
*
{{Orbital launches in 2001
Russian components of the International Space Station
Spacecraft launched in 2001
2001 in Russia
Spacecraft which reentered in 2021