Two crew members of the International Space Station (ISS) began their spacewalk on Friday, the Mission Control Center outside Moscow said. The main task of the spacewalk is to install a docking port for Russia's small research module MIM-2, a space vehicle scheduled to blast off in autumn, said Valery Lyndin, spokesman for the Mission Control Center. The pair, Russian Commander Gennady Padalka and U.S. Flight Engineer Michael Barrett, also planned to install an antenna to aid docking during the over five- hour spacewalk, Lyndin was quoted as saying by the Interfax news agency. The spacewalk was delayed by about one hour because the astronauts spent more time to check the pressurization of the adapter section and the state of all systems of Russia's new Orlan-MK spacesuits. Three astronauts joined the three crew members already on board the space station in late May and formed a six-member permanent crew for the first time. 