NASA footage of spacewalking astronauts over the weekend has been released.

Expedition 64 flight engineers Kate Rubins and Victor Glover - both NASA astronauts - have spent more than seven hours working outside the station during the spacewalk to mount upgrade kits for new solar arrays.

They worked on the portside edge of the station to mount a bracket and support struts on two mast canisters at the base of the outpost's current solar wings - but they were only able to install one of the kits while assembling a second and saving it for later.

"They completed the construction of upper support hardware and secured it to the space station's exterior structure until work can be completed on the next spacewalk Friday," NASA officials said in an update.

The International Space Station, parts of which have been in orbit since 1998, is preparing for new solar panels. NASA reports the oldest group of panels have been running continuously since December 2000 and are still performing well despite their advertised 15-year service life. But the arrays don't produce as much power as they used to.

As a result of advances in solar technologies, the latest arrays will be smaller than existing ones. They will be installed to roll out in front of the six current arrays, allowing future deployments to use the technology already in place for the original array, according to NASA. With the support of its subsidiary Spectrolab and a major supplier, Deployable Space Systems, Boeing will provide the arrays.

The crew hopes to install two sets of struts on two worksites near the solar arrays. At each spot, they use a portable foot restraint and a strut to anchor in place before adding a left strut, a right strut and a middle strut. The astronauts decided to secure thermal blankets over each strut. Rubins also wore a new high-definition video camera on her spacesuit, the first for U.S. spacewalks, to provide better views.

Another spacewalk to continue the construction of the structure is expected for later this week. Rubins and Japanese astronaut Soichi Noguchi would exit the station March 5.

Below is a replay of the astronauts' daring spacewalk.