ISS Russian Segment

Docking compartment Pirs

Docking compartment Pirs

Docking compartment Pirs


  • support for extravehicular activities (spacewalks to deploy ISS RS and to carry out a program of fundamental and applied research and experiments);
  • creation of an additional docking port, enabling Russian manned and cargo transportation spacecraft to dock with and function within the space station;
  • providing pass-through propellant transfer from Progress cargo transportation spacecraft through its own refueling lines supporting venting prior to the undocking with the transportation spacecraft;

Key specifications

Parameter Value

Launch mass, kg

4 350

Mass in orbit, kg

3 580

Mass reserved for deliverable cargo, kg


Length (with docking units), mm

4 910

Maximum diameter, mm

2 550

Volume of the pressurized compartment, m3


Docking compartment Pirs consists of a pressurized hull carrying equipment, service systems and structural elements supporting spacewalks. On the outside the hull is covered with micrometeoroid shield panels 1 mm thick and multilayer insulation.

Two docking units - one active and one passive - are located along the longitudinal axis of the docking compartment Pirs. The active docking unit is intended for pressure-tight mating with Zvezda Service Module. The passive docking unit located on the opposite side of the compartment is intended for pressure-tight mating with transportation spacecraft of the Soyuz and Progress type.

Progress M-CO1 on the launch pad

LV with CV Progress M-CO1 on the launch pad

Installed in the hull are two ring frames with hatches for spacewalks. Both hatches have inside diameter of 1000 mm. Each cover has a window with inside diameter of 228 mm. The two hatches are completely equivalent and can be used depending on which side of the Pirs compartment is more convenient for performing a spacewalk. Each hatch is designed for 120 opening cycles. To make cosmonauts' work in open space more comfortable, there are ring handrails around the hatches both inside and outside the compartment.

Handrails are also installed outside all the hull elements of the compartment in order to make it easier for the crew to work during spacewalks.

The vehicle for delivery and integration of the docking compartment into ISS RS was a specialized cargo spacecraft developed on the basis of Progress M cargo transportation spacecraft.

On September 15, 2001, after completion of the full cycle of prelaunch processing at Baikonur, the cargo spacecraft/module was launched to the space station. On September 17, it was successfully docked with the nadir port on the ISS RS Service Module Zvezda.

During the time of Pirs operation as a part of ISS RS, there have been almost 50 spacewalks supporting space station deployment and the program of fundamental and applied research and experiments.

Module Pirs as part of RS ISS

Module Pirs as part of RS ISS

ISS Crew

Hoshide  AkihikoHoshide

leg Novitskiy Novitskiy

Petr Dubrov Dubrov

Mark Vande Hei Vande Hei

Robert Shane

Megan McArthur McArthur