Spacewalking astronauts ventured out Sunday to install support frames for new, high-efficiency solar panels arriving at the International Space Station later this year.

Nasa’s Kate Rubins and Victor Glover put the mounting brackets and struts together, then bolted them into place next to the station’s oldest and most degraded solar wings.

They had to carry out the hundreds of pounds of mounting brackets and struts in 8ft bags. The equipment was so big and awkward that it had to be taken apart like furniture, just to get through the hatch.

Some of the attachment locations required extra turns of the power drill and still were not snug enough, as indicated by black lines.

The astronauts had to use a ratchet wrench to deal with the more stubborn bolts, which slowed them down. At one point, they were almost an hour behind.

“Whoever painted this black line painted outside the lines a little bit,” Mr Glover said at one particularly troublesome spot.

“We’ll work on our kindergarten skills over here,” Mission Control replied, urging him to move on.

With more people and experiments flying on the space station, more power will be needed to keep everything running, according to Nasa.

The six new solar panels, to be delivered in pairs by SpaceX over the coming year or so, should boost the station’s electrical capability by as much as 30%.

Ms Rubins and Mr Glover worked on the struts for the first two solar panels, due to launch in June.

The eight solar panels there now are 12 to 20 years old, most of them past their design lifetime and deteriorating.

Each panel is 112ft long by 39ft wide. Tip to tip counting the centre framework, each pair stretches 240 feet, longer than a Boeing 777′s wingspan.

Boeing is supplying the new roll-up panels, about half the size of the old ones but just as powerful thanks to the latest solar cell technology.

They will be placed at an angle above the old ones, which will continue to operate.

A prototype was tested at the space station in 2017.

Rubins’ helmet featured a new high-definition camera that provided stunning views, particularly those showing the vivid blue Earth 270 miles below. “Pretty fantastic,” observed Mission Control.

Sunday’s spacewalk was the third for infectious disease specialist Rubins and Navy pilot Glover, both of whom could end up flying to the moon.

They are among 18 astronauts newly assigned to Nasa’s Artemis moon-landing programme. The next moonwalkers will come from this group.

Last week, US vice president Kamala Harris put in a congratulatory call to Mr Glover, the first African American astronaut to live full time at the space station.

Nasa released the video exchange Saturday.

“The history making that you are doing, we are so proud of you,” Ms Harris said. Like other firsts, Mr Glover replied, it will not be the last. “We want to make sure that we can continue to do new things,” he said.

Ms Rubins will float back out on Friday with Japanese astronaut Soichi Noguchi to finish the solar panel prep work, and to vent and relocate ammonia coolant hoses.

Mr Glover and Mr Noguchi were among four astronauts arriving via SpaceX in November. Ms Rubins launched from Kazakhstan in October alongside two Russians. They are all scheduled to return to Earth this spring.