China launches longest-ever manned space mission

China has launched its longest-ever manned space mission. Two Chinese astronauts have been sent into orbit to conduct experiments aboard a space laboratory. Beijing hopes to have the station permanently occupied by 2020. Al Jazeera’s science editor Tarek Bazley explains. Subscribe to our channel: http://aje.io/AJSubscribe Follow us on Twitter:   / ajenglish   Find us on Facebook:   / aljazeera   Check our website: http://www.aljazeera.com/