The U.S. and Russian crewmen of the international space station are carrying out a maintenance spacewalk. It is a repeat effort to fix a vital control mechanism following last week's aborted attempt.
The task for astronaut Mike Fincke and cosmonaut Gennady Padalka is to restore electricity to one of three functioning gyroscopes that point and stabilize the station. Two are sufficient, but station officials want a spare.
If the problem remains and another gyro fails, jet thrusters would have to be employed to position the station, using precious fuel.
The repair effort stalled last Thursday when astronaut Fincke lost pressure in the oxygen tank of his Russian space suit because of a faulty switch.
The two crewmen are again wearing Russian spacesuits for this outing because the U.S. suits have cooling problems.
The Russian outfits make the spacewalk slower and riskier than normal. Wearing them required the men to depart from the Russian hatch to a worksite that is near the U.S. module, forcing them to travel a greater than usual distance across the outpost before beginning the job.
They are also out of site of the Russian module's antennas, which could mean communications blackouts. So the crewmen have worked out hand signals if necessary to communicate.