Video: Expedition 50 spacewalk highlights

Astronauts Jeff Williams and Kate Rubins ventured outside the lab complex Friday for a long-awaited spacewalk to attach a new docking mechanism, the first of two that will be used by U.S. crew ferry ships being built by Boeing and SpaceX to carry astronauts to and from the outpost, ending NASA’s sole reliance on Russian Soyuz spacecraft.

Two NASA astronauts will take part in the first all-female spacewalk this week, a critical outing to restore lost power in the wake of an equipment failure that cropped up after new batteries were installed in the International Space Station’s solar power system during two earlier spacewalks.

International Space Station managers Friday cleared astronauts Barry “Butch” Wilmore and Terry Virts to proceed with a third spacewalk Sunday, as originally planned, after concluding a small amount of water in Virts’ space helmet after an EVA Wednesday was an understood condition and not a threat to crew safety.