With private companies like SpaceX and Blue Origin now venturing into commercial spaceflight, the International Space Station (ISS) is expecting more spaceship traffic in the coming years.

Before that can happen, however, the space station has to have a "parking spot" for all upcoming commercial spaceships.

On Friday, Aug. 19, two NASA astronauts successfully installed a new docking port at the ISS, ending the United States' dependence on Russia for rides to the orbiting outpost.

Astronauts Jeff Williams and Kate Rubins hovered outside the space station for a spacewalk that lasted five hours and 58 minutes to attach the first of two international docking adaptors. The second docking adaptor will be launched to the space station in late 2017.

Williams, who is currently the Station Commander of the six-member crew, has performed a spacewalk four times in his career, while Rubins, who is the flight engineer, experienced the spacewalk for the first time.

For more than two hours, the two astronauts attempted to tie down the docking adaptor, which had been built by Boeing, and successfully attached it. The adaptor is around 1 meter (42 inches) in height and 1.6 meter (63 inches) in width.

After installation, the robotic machinery at the ISS completed the hard mate, successfully making it permanent.

During the rest of the mission, Williams and Rubins linked data and power cables for the adaptor. These fittings will allow the space station to share data and power with visiting spacecraft.

"With that, we have a new port of call," Rob Navias, NASA commentator, said as the space station floated over Singapore at 10:40 a.m. (1440 GMT).

Kenneth Todd, the operations integration manager at the ISS, described the installation as a significant milestone in the aspect of establishing commercial crew capability.

NASA believes the new docking port at the space station is the "gateway to a future" that will allow a new generation of American spacecraft to lift astronauts to space.

According to NASA, the new adaptors will work with SpaceX's Crew Dragon and Boeing's CST-100 Starliner, both of which are still under construction and are expected to ferry astronauts to the space station.

The new adaptor is more sophisticated than past equipment as it will enable automatic parking instead of the grapple and berthing process, NASA said.

Rubins and Williams will perform another spacewalk on Sept. 1 to revoke a solar array cooling panel no longer in use, as well as to install a television camera on the exterior frame of the ISS.

Watch the video below to witness the two astronauts' recent feat.