CRI:
My question is for Mr. Li Jian. We know that you are the commander of the Monitoring, Control and Communication Department, and also experienced the entire mission from the front line. How do you value the mission? Compared with previous docking missions, what are the new difficulties and challenges this time? Is there any technologic breakthrough?
Li Jian:
The Tiangong 2 and Shenzhou 11 missions have been completed successfully. The entire in-orbit flight and control plan, space experiments and key technologies have been verified and achieved various breakthroughs. Compared with previous docking missions, the differences are as follows: Firstly, it was a mission of long duration. Our astronauts orbited for 33 days, one time longer than the previous flight. Secondly, the orbit was a totally new one, operating at a range of 393 kilometers, or 50 kilometers higher than the previous one, which will be used for our country's space station in the future. Operating in this orbit, the calculation of the launch window, long-distance guidance and control strategy, including returning control all needed redesign, resulting in a series of breakthroughs in key technologies, such as fast orbit determination of return vehicle and preparations for return. All these formed new challenges.
Thirdly, during the combination period, we successfully released an accompanying satellite for the first time. This needed frequent and difficult control procedures. We have realized satellite fly-by of the combination and maintenance at the assigned position, both of which are very difficult to achieve. Fourthly, there were many in-orbit projects, such as the mechanical arm in-orbit operation calling for coordination between man and machine and cooperation between the astronauts and ground control. By completing the mission successfully, we also achieved breakthroughs in a range of key technologies.