China astronauts in first space walk to assemble robotic arm

Two astronauts made the first spacewalk outside China's new orbital station on Sunday to work on setting up a 15-meter (50-foot) long robotic arm. Liu Boming and Tang Hongbo were shown by state TV climbing out of the airlock as Earth rolled past below them. The third crew member, commander Nie Haisheng, stayed inside. The astronauts arrived June 17 for a three-month mission aboard China's third orbital station, part of an ambitious space program that landed a robot rover on Mars in May. Their mission comes as the ruling Communist Party celebrates the 100th anniversary of its founding. The station's first module, Tianhe, or Heavenly Harmony, was launched on April 29. That was followed by an automated spacecraft with food and fuel. Liu, Nie and Tang arrived on June 17 aboard a Shenzhou capsule. On Sunday, Liu and Tang were completing the installation of a robotic arm that will be used to assemble the rest of the station, according to state media.