Two American astronauts Wednesday stepped out on the second of three spacewalks to prepare the International Space Station for the arrival of commercial capsules ferrying astronauts in the coming years.
Commander Barry "Butch" Wilmore and flight engineer Terry Virts emerged from the station airlock after placing their suits on internal battery power at 6:51 am (12:51 GMT), NASA said.
The team's goal for the six-plus hour spacewalk is to route two bundles of cable, lubricate parts of the space station's robotic arm and prepare for another operation later this year to move modules around at the orbiting outpost.
The work aims to set up additional docking ports -- which are essentially parking spots for space taxis -- at the ISS for the arrival of more crew-carrying spacecraft.
Boeing plans to send its first astronaut to space aboard the CST-100 spaceship in late 2017, followed by SpaceX soon after.