NASA astronauts Nick Hague and Andrew Morgan successfully installed a docking port delivered by SpaceX last month. It will be used by SpaceX and Boeing once they start launching astronauts to the orbiting lab late this year or early next year.

The two had to wrestle with old, stiff cables in order to get power and data flowing to the port. They also attached reflectors for navigation.

"Really well done ... You gave us a brand new docking port for our next-generation spacecraft," Mission Control radioed as the 6 ½-hour spacewalk ended.

This is the station's second docking port for commercial crew capsules. The first was attached three years ago. The newest port was a replacement for one that was destroyed during a SpaceX launch accident in 2015.