Russian cosmonauts Sergei Ryzhikov and Sergei Kud-Sverchkov have completed a spacewalk to inspect a docking compartment on the International Space Station (ISS) in preparation for the installation of a Russian research module next year.
Ryzhikov and Kud-Sverchkov spent nearly seven hours on the space walk on November 18. It was the first for both cosmonauts.
The cosmonauts began the spacewalk around 10 a.m. (1500 GMT) and reentered the Poisk docking compartment airlock at about 5 p.m. (2200 GMT), NASA said.
Their mission was to inspect the Poisk airlock for leaks among other tasks such as relocating an antenna cable, retrieving hardware that measures space debris impacts, and repositioning an instrument used to measure the residue from thruster firings.
They had to scrap one of their tasks because of a stubborn bolt that prevented them from replacing a fluid-flow regulator on Russia's oldest compartment on the ISS, Zarya.
NASA said the old regulator was still working and the swap would be deferred to a later spacewalk.
The mission included preparations for the installation of the Nauka research module, which is to be delivered next year from the Russian-leased Baikonur Cosmodrome in Kazakhstan about a decade late because of a string of repairs.
The 22-ton lab, stretching 13 meters, is so big that it will be launched by a powerful Proton rocket. Once at the ISS, it will double as an air lock and docking port.
Relocating the antenna cable was the first step in decommissioning Russia's old Pirs spacewalking compartment to make room for the new lab.
The Pirs module will be removed and junked next year. Plans call for a cargo ship to be attached to it and used to guide it to a fiery reentry.