Astronauts at the International Space Station (ISS) have carried out an unscheduled fourth spacewalk to finish tasks left over from their last outing.
Patrick Forrester and Steven Swanson set up a rotating joint allowing solar wings to track the Sun to provide power for the station.
Meanwhile computer processors which had crashed were repaired.
The station's commander said the recent work meant the ISS was now returning to a "normal mode of operations".
Sunday's six-and-a-half-hour spacewalk was the fourth since the space shuttle Atlantis docked with the ISS last week.
It was performed in order to complete tasks initially planned for a spacewalk on Friday.
Astronauts on Friday had to repair the shuttle's thermal blanket which was damaged when Atlantis launched on 8 June.
On Monday, flight controllers on the ground plan to test the new solar wings to see if they track the Sun accurately.
Atlantis is expected to undock with the ISS on Tuesday and land in Florida on Thursday.
The crew of Atlantis was originally due to spend 11 days at the ISS, but the mission has since been extended to 13 days to carry out the thermal shield repairs.
This was supposed to be the second shuttle mission of 2007, but a freak storm over the Florida launch site in late February caused hail damage to the shuttle and delayed the mid-March flight.
Despite the delays, managers are confident they will be able to complete the ISS before the shuttles' 2010 retirement date.
Nasa plans to fly 15 more missions to the station to deliver large components, spare parts and other supplies. In addition, one final servicing call to the Hubble Space Telescope is planned for September 2008.