Spacewalking astronauts replaced a broken antenna outside the International Space Station after getting Nasa’s all-clear for orbiting debris.
US astronauts Tom Marshburn and Kayla Barron were supposed to complete the job on Tuesday, but Nasa delayed the spacewalk because of potentially threatening space junk.
Nasa later determined the astronauts were safe to go out, despite a slightly increased risk of a punctured suit from satellite wreckage.
But soon after the spacewalk ended, Mission Control notified the crew that the station would need to move into a slightly lower orbit on Friday to avoid an old US rocket fragment.
Last month, Russia destroyed an old satellite in a missile test, sending pieces everywhere.
Nasa is not saying whether that event was the source of the junk that delayed the spacewalk.
During the first National Space Council meeting under Vice President Kamala Harris this week, top US government officials joined her in condemning Russia’s extensive debris-scattering last month.
More than 1,700 sizeable pieces of the shattered satellite are being tracked, with tens if not hundreds of thousands too small to see.
Ms Barron reported at least 11 small debris strikes to the failed antenna that was removed during the spacewalk, with some of the holes looking old.
The device, up there for more than 20 years, malfunctioned in September.
Mr Marshburn, 61, became the oldest person to conduct a spacewalk.
It was the fourth of his career.
Ms Barron, a 34-year-old space debutante, ventured out on her first.
They flew up on SpaceX last month for a six-month stay.
Two other Americans are aboard the space station, along with two Russians and one German.