Two Russian cosmonauts wearing bulky spacesuits used the International Space Station’s poisk docking compartment for the first time on Wednesday as an airlock on a spacewalk to prepare the nearly identical Pirs module for removal next year. A new laboratory module will later be parked in its place.
Expedition 64 commander Sergey Ryzhikov and Sergey Kud-Sverchkov began the eighth spacewalk of the year at 10:12 a.m. EST. The excursion, the first for both cosmonauts, takes place just two days lateron board a SpaceX Crew Dragon commercial ferry.
For identification purposes Ryzhikov, callsign EV-1, wears a spacesuit with red stripes and helmet camera 20, while Kud-Sverchkov, EV-2, wears a suit with blue stripes and helmet camera 18.
Almost identical to Pirs, Poisk was launched almost exactly 11 years ago, on November 10, 2009, and was attached to the upper port of the Zvezda module two days later. It has been used as a docking port for Progress non-piloted cargo ships and Soyuz ferries many times, but never as an airlock.
Before venturing outside, the cosmonauts spent about an hour ensuring that Poisk’s never-before-used side hatch could be securely opened and closed with an airtight seal, and that the hatch leading into the main body of the station was inside the Compartment is leak-free at or near vacuum.
Ryzhikov and Kud-Sverchkov wear their Orlan spacesuits and partially depressurise Poisk for a first round of leak tests. NASA crewmate Kate Rubins conducted similar tests in the Russian segment of the station.
The cosmonauts then took Poisk to vacuum, opened the side hatch for the spacewalk for the first time in the history of the module, and examined the seals for any signs of foreign objects or damage. Replacement gasket material is available if required, but no signs of problems were found upon inspection.
Then they closed the hatch and performed additional leak tests before reopening it and floating outside just after 11 a.m. to begin the 232nd spacewalk dedicated to the assembly and maintenance of the station, the eighth EVA station this year .
The first item on the agenda was the replacement of a liquid flow regulator on the Russian Zarya module, the first component of the station, which was introduced 20 years ago on November 20th.
The cosmonauts then planned to get a materials science exposure palette out of the Pirs module and disconnect a telemetry cable. The cable is reconnected to Poisk, thereby ending the use of Pirs as an airlock.
After cleaning a window on the Zvezda module, the spacewalkers planned to reposition a rocket flag impact detector and get an experimental tray that engineers can use to assess the effects of micrometeoroids. Your final assignment is to photograph the exterior of the Russian segment.