Astronauts making the last spacewalk of Nasa's space shuttle era have retrieved a broken pump from the International Space Station and installed a "fill-er-up" experiment for a robot.
The space station's two-armed robot Dextre will not tackle the 22.6 million dollar play set - a fancy Fisher-Price toy as one astronaut describes it - until long after Atlantis departs and the shuttle programme ends.
But perhaps more than anything else on this final journey by a shuttle, the robotic demo illustrates the possibilities ahead for Nasa - satellite-refuelling stations in space run by robots.
In a departure from previous shuttle visits, the spacewalking job fell to space station astronauts, Michael Fossum and Ronald Garan Jr, who teamed up for three spacewalks in 2008. The four-person Atlantis crew is the smallest in decades, and so the lone spacewalk of the mission was handed over to the full-time station residents.
It was the 160th spacewalk in the 12 and a half-year life of the orbiting outpost, and the last one planned for Americans for more than a year.
Fossum and Garan completed the two major chores - the pump removal and robotic test hookup - inside of three and a half hours. They spent the rest of the six and a half-hour spacewalk on a variety of small tasks. The two paused during their spacewalk to admire the view 245 miles below - Kennedy Space Centre - and on the next swing around the world, Houston, home to Mission Control.
While the spacewalk unfolded, some of the eight astronauts inside worked to unload the nearly five tons of supplies that were delivered in a giant cargo carrier by Atlantis. It represents a year's worth of food, clothes and other housekeeping items, to tide the crew over in case commercial rocket makers fall behind in their own cargo runs. The first such haul is supposed to take place by year's end.
Until now, the shuttle has hoisted the bulk of supplies to the space station. Cargo runs by Russia, Japan and Europe will continue.
Nasa is turning to private enterprise in the post-shuttle period, so it can meet the White House goal of sending astronauts to an asteroid by 2025 and Mars the decade after that.
The 13-day flight by Atlantis is the last for the 30-year shuttle programme. Atlantis is due to return on July 21 to Kennedy, where it will go on display at a tourist centre.