Astronauts aboard the international space station conducted their second and last space walk Tuesday before heading for home later this month.
The excursion outside the orbiting outpost by space station commander Ken Bowersox and science officer Don Pettit was the first space walk carried out since the US space shuttle Columbia tragedy in February.
The two astronauts spent about six and a half hours on completing their scheduled tasks and then performed some get-aheadones, the US space agency NASA said.
Shortly after the start of the space walk, Bowersox reconfigured connectors between the girder-like trusses and Pettitreplaced a power relay box in the station's rail car which can move long tracks on the outside truss framework.
The two space-walkers also rerouted power cables to devices which provide orientation control to the station and placed clampson coolant system lines to prevent internal leakage.
While Pettit and Bowersox worked outside, Russian astronaut Nikolai Budarin assisted from inside the station and monitored thestation systems.
Pettit, Bowersox and Budarin, under the name of Expedition Six,have been aboard the space station since last November. They had been scheduled to return to Earth in March, but their stay was extended after NASA grounded the US shuttle fleet in the wake of the Columbia accident.
The three astronauts are now slated to depart the space stationlater this month aboard a Russian Soyuz spacecraft. They will be replaced by a smaller crew which consists one US astronaut and a Russian cosmonaut.