One arrow in ten years ＂asks the sky＂

　　CCTV News:The successful launch this afternoon (July 24th) is the first experimental module of China’s space station, which consists of three parts: the working module, the airlock module and the resource module. It is the heaviest single-cabin active aircraft in the world. The candlestick experimental module has the backup function of several key systems in the core module. It can be said that it is of great significance to the construction of China’s space station, and its many innovative technologies have also set many new records in the development of spacecraft in our country, which is another major achievement made by China Aerospace in its efforts to achieve high-level self-reliance.　

　　Behind such a great achievement, the average age of the designer team of the candlestick experimental cabin is only in their thirties, and they are a group of young people. Today’s story about China Space Station, we will listen to the innovative stories of these young people. One arrow in ten years, "ask the sky", to feel the innovative power of this young designer team.

　　At 14: 22 this afternoon, the Changwu B rocket carrying the candlestick experimental module was successfully launched.

　　Just as everyone was taking a group photo to celebrate, one team was still staring at the computer screen nervously, waiting for an important news.

　　About an hour after the launch, the solar wing of the candlestick experimental module unfolded smoothly. Until then, the hanging heart of the team relaxed a little.

　　Zhang Jiao, chief designer of the overall system of the candlestick experimental cabin of the Fifth Academy of Aerospace Science and Technology Group:The deployment of solar wing windsurfing is the most important key event in the early stage of our orbit. Only if it succeeds can our aircraft fly smoothly and safely.

　　Zhang Jiao is the chief designer of the overall system of the candlestick experimental module, and his team is the team of designers who have been with the candlestick experimental module for ten years.　

　　The flexible solar wing is deployed in sections to ensure the attitude stability of the experimental cabin.

　　In order to provide enough energy for the space station, the space experiment module carries two huge flexible solar wings, and the length of each wing can reach 28 meters. In order to ensure the attitude stability of the space experiment module, the solar wings adopt a brand-new deployment method — — Expand in sections.

　　Zhang Jiao, chief designer of the overall system of the candlestick experimental cabin of the Fifth Academy of Aerospace Science and Technology Group:First of all, in the solo flight stage, expand the length by 1/3 to 1/4, and expand it by about 6.5 meters, so that it can fly in a contracted way first. After the contracted flight, its stiffness will be good and its control will be stable. When we finish the rendezvous and docking, it will be completely expanded again.

　　On March 30, 2012, that is, ten years ago, the space station officially shifted from the scheme demonstration stage to the scheme design stage. On the second day, Zhang Jiao, who had just returned from studying abroad, joined the team of space station designers as he wished. In the past ten years, the team of designers, including Zhang Jiao, has overcome many difficulties, constantly innovated and searched for the best solution. In their view, it is the responsibility of their generation of astronauts to do a good job in the space station and use it well in the future.

　　Zhang Jiao, chief designer of the overall system of the candlestick experimental cabin of the Fifth Academy of Aerospace Science and Technology Group:On the second day, I officially entered a node of the conceptual design of the space station and joined the design team of the space station. Therefore, I will keep this day in mind.　

　　How to successfully transfer the space migration and transposition experiment module?

　　Just as Zhang Jiao, a young and energetic man, was about to make a big splash, reality poured cold water on him. After the rendezvous and docking of the port and the core module in the previous paragraph, the candlestick experimental module needs to be transferred to the lateral port before the launch of the Mengtian experimental module. Two big guys weighing more than 20 tons have to complete the migration and transposition in space, and they may roll and drift if they are not careful. What attitude the space station will take to complete this ultra-difficult action is puzzling everyone.

　　Zhang Jiao, chief designer of the overall system of the candlestick experimental cabin of the Fifth Academy of Aerospace Science and Technology Group:In what form? What actuator is used for transposition? How to decompose the function of transposition? How to match the time sequence? How to verify the ground? Is the link of verification covered? What can each covered link come back? Answer me, how did my technical indicators match? These are all questions we need to answer, and we haven’t slept well for two years.

　　Task-level experiment, function-level experiment, test verification, model flight test, etc. In two years, the team of designers made thousands of experiments through simulation, and finally found the most stable and reliable flight attitude.

　　Zhang Jiao, chief designer of the overall system of the candlestick experimental cabin of the Fifth Academy of Aerospace Science and Technology Group:We found that such a transposition posture based on gravity gradient stability is the smallest for posture drift in the transfer process, that is to say, before transposition, I first set the cabin up and turned it into a slender one-line combination. For example, I hold this pen like this, which is actually very easy to roll and roll, but if I hold it, it will be stable by gravity gradient, which is a form of my center of gravity, and it is a basically quasi-stable combination.

　　At 6: 59 on January 6, 2022, after about 47 minutes of cross-system close cooperation, the test of the space station manipulator to transfer the cargo spacecraft was a complete success. This is the first time that China has used the space station manipulator to operate a large-scale on-orbit aircraft for the transfer test.

　　Zhang Jiao, chief designer of the overall system of the candlestick experimental cabin of the Fifth Academy of Aerospace Science and Technology Group:During the transposition of Tianzhou-2, we have verified the basic configuration and posture in advance, so the scheme we designed before is reasonable, so our subsequent transposition of the experimental module will also follow this posture scheme.　

　　Designer team: it is the responsibility of astronauts to do a good job in the space station

　　Overcoming the problem of transposition is only the tip of the iceberg in the development process of the experimental capsule. The summary document of the initial sample development stage of the experimental capsule from June 2014 to December 2020 has nearly 700 pages and more than 600,000 words.

　　Zhang Jiao, chief designer of the overall system of the candlestick experimental cabin of the Fifth Academy of Aerospace Science and Technology Group:We have nearly 4,000 fault mode countermeasures just for the rendezvous and docking of the experimental capsule and the linear construction of the two capsules, and we can accurately locate and identify the fault at the first moment, and we can deal with it in time.

　　Different from other types of spacecraft, the results can often be seen after several years of development cycle, and the development of the space station took ten years. In this decade, the team of space station designers had no chance to celebrate, but only insisted on sitting on the bench.

　　Zhang Jiao, chief designer of the overall system of the candlestick experimental cabin of the Fifth Academy of Aerospace Science and Technology Group:It was not until the launch of the core cabin on April 29 last year that we really felt the joy of the first copy. Doing a good job in the space station is to design it well, develop it well, and use it well again, which is the responsibility of our generation of astronauts.

　　Zhang Hao, the overall chief designer of the space station system of the Fifth Academy of Aerospace Science and Technology Group:Everyone is United in their efforts, and there is nothing else. They are all thinking about how to do this thing and this model well and do this business well.

　　Zheng Hao, deputy chief designer of the space station system of the Fifth Academy of Aerospace Science and Technology Group:The launch vehicle played perfectly and a big stone in my heart fell to the ground. I hope everything goes well in the following work, and then the rendezvous and docking will be completed perfectly tomorrow, which is an important step in the construction of our space station.