Washington  - Two crew members aboard the International Space Station (ISS) completed a spacewalk early Tuesday after almost six hours in space.

US Commander Mike Fincke and Russian flight engineer Yuri Lonchakov resealed the airlock at 7:30 am (0630 GMT) after a mission to collect science experiments attached to the outside of their orbiting home, the Itar-Tass news agency reported, citing Russian officials.

The pair scheduled a device to measure electromagnetic potential around the station's Russian-made module.

The tests are part of an investigation of misfiring explosive bolts used to detach Soyuz capsules that have carried ISS crews back to Earth. (dpa)