Astronauts have squeezed in one last spacewalk before turning their attention to the end of SpaceX’s first crew flight.
Nasa’s Bob Behnken and Chris Cassidy floated out of the International Space Station on their fourth and final spacewalk in under a month.
Instead of swapping batteries, they had to route cables, hook up a tool storage chest and perform other maintenance.
It was the 10th spacewalk in each of their careers, tying the US record set by previous space station residents.
In less than two weeks, Mr Behnken and Doug Hurley, who monitored the spacewalk from inside, will leave the orbiting complex in the same SpaceX Dragon crew capsule in which they arrived at the end of May.
The two-man crew blasted off on a Falcon 9 rocket at 8.22pm on May 30 – in the first ever space mission run by a private company.
SpaceX Falcon 9 launch - in pictures
The two men on board the Dragon capsule, operated by billionaire Elon Musk’s firm, were greeted by Mr Cassidy the next day, as well as two other space station residents, Russia cosmonauts Anatoli Ivanishin and Ivan Vagner.
The mission, named Demo-2, marked the first time Nasa had launched astronauts from US soil in nine years.
SpaceX is aiming for a splashdown off the Florida coast in August - the first for astronauts in 45 years.
Weather permitting, the Dragon capsule will parachute into the Gulf of Mexico off the Florida Panhandle.
Nasa administrator Jim Bridenstine said once Tuesday’s spacewalk is finished, the astronauts are "going to be focused like a laser on coming home".
He said the SpaceX test flight has gone exceedingly well so far.
"And I’m knocking on wood because it is not over until Bob and Doug are home," he said at a Space Foundation panel discussion.
The first-stage booster used to launch Mr Behnken and Mr Hurley on May 30 blasted off for a second time on Monday from Cape Canaveral.
It landed on a floating platform in the Atlantic after hoisting a satellite for South Korea’s military, to be used again for another flight.
Additional reporting by the Associated Press