Two astronauts on the US space shuttle Endeavour have completed a seven-hour spacewalk as part of an effort to repair the International Space Station.
Americans Heidemarie Stefanyshyn-Piper, 45, and Steve Bowen, 44, cleaned and lubricated the station's three double solar antenna arrays attached to the orbiter's exterior.
The spacewalk, the longest of the 15-day mission, which began on 15 November, was completed just before 1am this morning (Irish time).
Captain Stefanyshyn-Piper and Captain Bowen worked on repairs of the ISS's starboard Solar Alpha Rotary Joint race ring and replacing trundle bearing assemblies.
The worn-out parts will be taken to Earth for inspection.
The complex work was orchestrated by Lt Col Shane Kimbrough, 41, who was on a spacewalk along with Ms Stefanyshyn-Piper last Thursday.
The mission's fourth spacewalk, continuing the repair work, is scheduled for tomorrow.
The spacewalks are part of an ambitious project designed to double the station's crew capacity from three to six.
As the two astronauts worked on the exterior, the rest of the seven-strong crew ferried equipment from the Endeavour to the ISS.
Starting last Wednesday, the team began installing a freezer and an oven for scientific experiments by NASA's Destiny Laboratory Module.
The additions also include two new sleeping quarters, exercise equipment, a second toilet, two more ovens and a refrigerator.
During an earlier spacewalk on Tuesday, Capt Stefanyshyn-Piper let slip her tool bag and watched helplessly as it floated off into the void of space.
Meanwhile, NASA experts continued to work on problems with a $250m (€200m) urine processor unit that is designed to process urine, perspiration and bath water into drinkable water.
NASA said a centrifuge motor inside the distillation unit was running too slow and drawing too much electrical current.
Once the unit was in place, it would no longer be necessary to ferry vast quantities of water to the space station.
The device is essential for doubling the accommodation capacity. It would also be able to recycle the 6.8 tonnes of waste water produced each year.
