Full coverage: China Tiangong-2 Space Lab Launch

For more on this, we are joined in the studio by Professor Yang Yuguang, a researcher at the China Aerospace Science and Industry Corporation.

Q1: Professor Yang, tell us more about the Tiangong-2 missions . How significant are those missions?

Q2: The two visiting astronauts will stay in space for 30 days, doubling China's previous record of 15 days. What does this 30-day stint mean? Has the space lab been specially designed to allow longer stays?

Q3: Experts say docking with China's first-ever cargo ship and on-orbit propellent refueling would be the most difficult of the primary missions. Why is this and have we got any experience from its predecessor Tiangong-1? 

Q4: Launched in September 2011, Tiangong-1 was in essence a target spacecraft. Tiangong-2, however, will serve as the first space laboratory. Between target spacecraft and space lab, what are the major differences?