Two Russian cosmonauts ventured outside the International Space Station (ISS) today in the latest spacewalk designed to prepare for the arrival of a Russian laboratory module later this year.

Flight Engineers Fyodor Yurchikhin and Alexander Misurkin opened the hatch to the Pirs docking compartment to begin their spacewalk estimated to take between six and seven hours at 10:39 a.m. EST, the main objective being rigging cables for the future lab and the installation of an experiment panel.

According to Reuters, the event marks the seventh spacewalk for Yurchikhin and the second for Misurkin.

"There's a lot of intricate and delicate stringing [of the cables] through handrails and hook points," NASA mission commentator Rob Navias explained during a broadcast of the spacewalk, the news outlet reports.

The walk marks the third of six scheduled to take place this year.

Meanwhile, NASA is still investigating the cause behind a recent helmet link in the case of astronaut Luca Parmitano that forced space officials to abort what was scheduled to be a six-hour spacewalk only an hour and a half in. According to NASA, the walk was also designed to help prepare the ISS for the forthcoming Russian lab, among other things.

At first, Parmitano suspected the water to simply be his own sweat and attempted to work through it, but was forced to stop when water floated into his eyes. According to Space.com, the unprecedented leak could have potentially drowned the astronaut had it not been caught in time.

"The mishap investigation board will look more broadly at past operations and maintenance, quality assurance, aspects of flight control and other organizational factors," agency officials stated in a press release issued a week after the event. "The board's responsibility is to make observations and recommendations that can be applied to improve the safety of all of NASA's human spaceflight activities."