Moscow, Aug 21 (IANS/RIA Novosti): Russian cosmonauts Gennady Padalka and Yury Malenchenko completed a six-hour spacewalk having carried out all planned maintenance tasks on the International Space Station (ISS).

The cosmonauts launched a microsatellite and collected a number of bio specimens from the surface of a docking module as part of the scientific experiment Biorisk.

The unique Biorisk experiment studies the impact of vacuum, subzero and hot temperatures and radiation on biological objects. It is impossible to simulate these processes on earth.

It was the first spacewalk of the current ISS Expedition 32. The expedition's Commander Padalka and Flight Engineer Malenchenko completed it in six hours ahead of the scheduled almost 6.5 hours.

The spacewalk was also initially delayed for 47 minutes due to some minor problems.

Both Padalka and Malenchenko are veteran cosmonauts with a lot of experience venturing outside the orbital station. It was the ninth spacewalk for Padalka and the fifth for Malenchenko in their space careers.