BEIJING (AP) — Two astronauts have made the first spacewalk outside China’s new orbital station using a 15-meter-long (50-foot-long) robot arm to install cameras and other equipment. State TV showed astronauts Liu Boming and Tang Hongbo climbing out of an airlock as Earth rolled past below them. The Chinese space agency said the two spent nearly seven hours outside the station. The third crew member 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.