Video: Expedition 50 spacewalk highlights

Check out photos taken by two astronauts who ventured outside the International Space Station on Saturday, running more than 300 feet of wiring that will eventually be connected to new docking ports to receive commercial spaceships built by Boeing and SpaceX.

Engineers clad in clean suits finished stowing last-minute cargo into SpaceX’s Dragon supply ship Friday, including 40 mice and bacterial research specimens, a day before it is scheduled to blast off to the International Space Station in the first flight from the Kennedy Space Center’s historic Apollo-era launch pad 39A since 2011.

Two spacewalkers attached a new docking port to the International Space Station Friday, clearing the way for U.S. crew ferry ships being built by Boeing and SpaceX to begin test flights to the lab complex next year.