A pair of astronauts stepped out of the International Space Station (ISS) on Saturday, Feb. 21, to install cables needed for the docking mechanisms that will be used by the SpaceX and Boeing commercial space taxis.

Expedition 42 Commander Barry Wilmore and Flight Engineer Terry Virts left the Quest airlock of the ISS at 7:45 a.m. EST for the spacewalk, the first of three by the duo to install over 750 feet of cables and communication gears.

The National Aeronautics and Space Administration (NASA) considered the task the most complicated of all cable-routing jobs in the space station's 16-year history.

The extensive rewiring is crucial to the arrival of the commercial space taxis that NASA has commissioned Boeing and SpaceX to build in a bid to end the dependence of the U.S. on Russia in transporting its astronauts to and from the space station in low Earth orbit.

"This will be the most complicated cable-routing task that we have performed (by spacewalkers) to date," said lead spacewalk official Karina Eversley.

Although the new commercial crew capsules' first flight may not happen until late next year, the U.S. space agency said that the ISS has to undergo significant transformation in order to prepare for these new vehicles.

During their Saturday spacewalk, Wilmore and Virts installed six cables to a docking port on the $100 billion space laboratory's Harmony module, which is also used for docking space shuttles. Wimore and Virts are expected to have their next spacewalks on Feb. 25 and Mar 1.

Once all the scheduled spacewalks are done, the ISS will have a total of 764 feet of new cabling and will be fitted with communications systems that would support SpaceX's Dragon capsules and Boeing's CST-100.

The spacewalk on Saturday was initially scheduled on Friday, Feb. 20, but mission managers decided to delay it for one day to ensure the health of critical spacesuit components. Failure of these components during a spacewalk could stop oxygen flow to the astronaut.

Wimore and Virts were able to accomplish their tasks in just under seven hours, ending their spacewalk at 2:26 p.m. with the repressurization of the Quest airlock.

"Wilmore and Virts completed all the scheduled tasks for today and one get ahead task," reported NASA. "They rigged a series of power and data cables at the forward end of the Harmony module and Pressurized Mating Adapter-2 and routed 340 of 360 feet of cable."

ⓒ 2018 TECHTIMES.com All rights reserved. Do not reproduce without permission.