Astronauts conduct spacewalk outside ISS

For the second time this week, two astronauts are conducting a spacewalk on the International Space Station.

During the spacewalk on Friday, NASA astronaut Kate Rubins and Japanese astronaut Soichi Noguchi, both crew members of Expedition 64, will complete work to prepare the ISS for solar array upgrades.

Shortly before 7 a.m., Rubins and Noguchi headed toward the unfinished work from Sunday’s spacewalk, located on the far port end of the orbiting lab. They needed to finish installing mounting brackets and struts, and tighten some sticky bolts.

The equipment will support the first set of improved solar panels, due to arrive in June.

NASA is upgrading the space station’s power grid to accommodate more astronauts and experiments, now that SpaceX is launching crews and Boeing should be too by year’s end. The eight solar panels up there now have degraded over time; the oldest were launched 20 years ago.

The six new solar wings — smaller but more efficient — will fit over the older ones and boost the station’s power capability by up to 30%. Boeing is supplying the panels, which will be launched in pairs by SpaceX over the next year.

During Sunday’s spacewalk, Rubins and NASA astronaut Victor Glover encountered a number of stubborn bolts that prevented them from completing the support set-up.

NASA decided the leftover work was more important than the other chores that had been scheduled for Friday’s spacewalk, namely venting and rearranging hoses for ammonia coolant. Future spacewalkers will deal with that.

The latest spacewalk should be the last for the station’s current residents, whose half-year missions are coming to a close.

Rubins will return to Earth in mid-April in a Russian capsule, along with two Russians. Noguchi, Glover and two other NASA astronauts will fly SpaceX back in late April or May.

The spacewalkers are expected to be outside the ISS in the vacuum of space for about six-and-a-half hours, according to NASA.

Friday’s spacewalk marks the fourth for both Rubins and Noguchi, the U.S. space agency noted in a tweet.

Learn more about Friday’s spacewalk and Expedition 64 here.

Watch the spacewalk live as it happens in the video player at the top of this story.

The Associated Press contributed to this report.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Use the form below to sign up for the ClickOrlando.com space newsletter, sent every Wednesday afternoon.