Two of the three astronauts worked outside the module for the first time, with the third helping from inside, operating a robotic arm. It's the first time China has used a robotic arm in this way. CGTN talks to Yang Yuguang, a professor from the China Aerospace Science and Industry Corporation, to share the differences between this extra-vehicular activity (EVA) and that of the Shenzhou-7 mission, as well as the significance of this mission.