The first half of Monday's spacewalk was a breeze as two Discovery astronauts removed a faulty part on the international space station, but a series of minor problems combined to temporarily gum up the rest of their work on what were supposed to be routine repairs.
At one point, a key device that keeps spacewalkers from floating away free nearly came loose.
Astronauts Piers Sellers and Michael Fossum started their 6 1/2-hour spacewalk by removing a severed cable reel from a crucial rail car on the space station with a simple pull. The cable provides power, video and data to the car.
"We're getting a workout," Fossum said.
But then the British-born Sellers had problems placing the removed cable reel into the shuttle's payload bay. Next, a gun-device that anchors spacewalkers nearly came loose; Sellers and Fossum were able to repair in about half an hour. Finally, Fossum had trouble installing the new cable reel, even with Sellers helping.
After much wrangling, the astronauts completed their tasks and started the lengthy process of cleaning up just under six hours into their spacewalk.
The spacewalk's more mundane tasks included installing a spare external pump compartment on the station's cooling system. The astronauts attached the pump compartment to the space station's robotic arm, and it was moved to where it will be installed on the station.
The spacewalk came a day after the astronauts received the good news that everything appeared safe for them to return to Earth aboard Discovery. The shuttle has been docked at the international space station since dropping off European Space Agency astronaut, German-born Thomas Reiter, to join the crew there.
Sellers came out of the hatch first, followed by Fossum, as the space station and Discovery passed about 220 miles (350 kilometers) above Spain, reports AP.