TIM FURNISS / LONDON & VLADIMIR KARNOZOV / MOSCOW
Pirs 1 Docking Compartment with also serve as back-up airlock for space walks
The Russian Pirs 1 Docking Compartment docked to the Russian Zvezda module aboard the International Space Station (ISS) on 16 September, two days after its launch attached to a modified M-CO1 Progress tanker aboard a Soyuz booster from Baikonur.
The 5m-long (16ft), barrel-shaped Pirs is the sixth habitable module to be launched to the ISS and the third by Russia. It will provide additional crew and equipment accommodation and a docking port for Soyuz and Progress craft.
Prior to the arrival of Pirs, Soyuz and Progress tanker craft could only dock with either the aft axial docking port of Zvezda or the nadir port of the Russian Zarya module. The added capability from Pirs will allow a Progress spacecraft to remain attached to the ISS when a new Soyuz vehicle arrives to replace an older Soyuz. Previously, the Progress had to be undocked before the arrival.
Pirs will also serve as the back-up extra vehicular activity airlock, equipped with a 1m diameter hatch, to complement the US Airlock Module. It carries a crane-like Strela deployable boom to be installed outside the ISS, a Soyuz capsule crew seat, a new spacesuit and various spares and equipment.
The new module can only support EVAs by crews wearing Orlan Russian suits. Three spacewalks are planned from it by the Expedition Crew 3 in October and November.
Pirs was to have been replaced by the Universal Docking Module (UDM), providing three ports for Soyuz and Progress craft and life-support for up to six crew. However, the UDM, scrapped due to a lack of funding, will be replaced by the Functional Cargo Block (FGB 2) module which was the reserve craft for the Zarya module launched in 1998.
The 70% complete FGB 2 requires modifications, including a new docking port and improved solar panels. The unit will be launched in 2003 aboard a Proton booster.
Source: Flight International
