MOSCOW, June 6 (Xinhua) -- International Space Station (ISS) crew members have started a six-hour space walk Wednesday evening, Itar-Tass news agency reported.

    "The hatches were opened at 18:23 Moscow time (1423 GMT)," Moscow-based Mission Control Center head Valery Lydnin said.

    Two Russian crew members, Fyodor Yurchikhin and Oleg Kotov, opened the ISS hatches and began extravehicular activities.

    The walk is designed to add the remaining 12 out of 17 meteorite shielding panels, which were delivered to orbit by the U.S. space shuttle Discovery last December, on the outer surface of the station.

    The first five panels have been assembled during their first space walk taken on the night from May 30 to 31.

    They will also place containers with microorganisms and other biological forms on the outer surface of the ISS in a bid to study the possibility of their survival in open-space conditions during eight months, which were needed for a flight to Mars and back, Itar-Tass said.

    NASA astronaut Sunita Williams will provide support to her Russian colleagues from inside the station.