China’s Tiangong-2 target spacecraft and the space station of China’s space station will have a “gold eye†– the first third-generation rendezvous and docking optical imaging sensor in China. The sensor not only "sees" but also "sees far", starting from hundreds of thousands of kilometers for the aircraft and the spacecraft to "thread the needle," and finally complete the docking. Dry Running Mechanical Seals Dry Running Cartridge Seals,Desulfurization Pump Seal,Dry Running Seal for FGD-Mechanical Seals Sichuan Zhongying Industrial Pump Co., Ltd , https://www.zygyb.com
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Recently, China's first third-generation rendezvous and docking optical imaging sensor was successfully developed.
As a research and development unit for this sensor, China Aerospace Science and Technology Corporation's five hospitals and 502 institutes started in 2011, and after four years of technological research, they completed the development of third-generation products. The key technical indicators of the new generation of products have reached or even exceeded the international advanced level.
"Millions of needles" need a good "eye"
The optical imaging sensor is a close-range imaging measurement sensor for rendezvous and docking of a spaceship and a target aircraft, which consists of a camera on the spacecraft and a target marker on the target aircraft. The camera performs imaging measurement on the marker to obtain the relative position and relative attitude data between the spacecraft and the target aircraft, and provides the relative navigation measurement information for the two aircraft.
Spacecraft and target aircraft are rendezvous and docked in space. After hundreds of thousands of kilometers of chase, they complete the “needle thread†action and perform the perfect “kiss†and eventually become one. Its translation is the most critical phase, and it is also the most difficult, most demanding and extremely risky phase. From the distance of 150 meters until the final docking, the optical imaging sensor is the only sensor that has both relative position and attitude measurement capabilities, like the "eyes" of an aircraft.
"If the 'eyes' are not good, it will lead to the failure of the rendezvous and docking mission or even the collision of two aircrafts, which will seriously threaten the safety of the astronauts and the spacecraft." The original product designer and the 502 optical imaging sensor business unit Zhao Chunhui, secretary of the branch, said that the optical imaging sensor has become the key stand-alone unit for the success of the rendezvous and docking mission, and there is no room for glitches.
Comprehensively improve safety
When two high-speed vehicles with speeds about 8 times faster than Zidan are approaching in flight, the "eyes" of the optical imaging sensor, the aircraft's "eyes", cannot be shaken even when the sun is shining, and they must be given to the target aircraft. The target marker photographs and determines the distance and attitude information after real-time analysis of the photograph.
In the previous rendezvous and docking mission between the Shenzhou spacecraft and the Tiangong-1 target aircraft, the first-generation rendezvous and docking optical imaging sensors were applied. The second-generation products are currently used on some experimental satellites and have successfully completed the measurement tasks. Outstanding. The research and development team did not satisfy the current situation. Based on the previous two generations of products, with a view to the future, a new generation of products was developed.
"The radiation intensity of sunlight in space is 3 to 5 times that of the Earth. The 'eyes' of aircraft are easily spoiled when rendezvous and docking." Gong Dezhu, chief designer of the 502 optical imaging sensor division introduced the adoption of new With the technology, the third-generation rendezvous and docking optical imaging sensor has been refined into a “eye-catching eye†that can “see†the target even under strong light conditions, which greatly improves the reliability of the rendezvous and docking.
“The improvement of the anti-stray light capability will also make the working arc of the rendezvous and docking of the aircraft longer and the on-orbit docking time reach about 2 times the original, which will also give the aircraft launch window period a greater choice.†The original spacecraft control points Xi Yongchun, the chief designer of the system and deputy director of the 502 Science and Technology Committee, introduced the project.
In addition, the developers also increased the time for the first capture of the target by the third generation product by an order of magnitude - from about 10 seconds to less than 1 second. "This time is just like the time when the driver was back to normal vision by the strong light shook his eyes." Product designer Guo Shaogang explained. At the same time, the response time of the third generation “eyes†from seeing the target to making judgments is also greatly shortened, and the security of the rendezvous and docking process is better guaranteed.
　　 "The third-generation rendezvous and docking optical imaging sensor will be applied to the Tiangong-2 target aircraft and the Chinese space station," said Wang Li, deputy director of the 502 optical imaging sensor unit.
According to reports, in the future, the personnel and cargo transportation of China’s space stations throughout the day will be more focused on grasping the timing of the rendezvous and docking, and the third-generation products can well meet this demand. At the same time, the successful completion of the development of a new generation of products has also laid a good foundation for the follow-up R&D team to refine R&D and adapt products to the diversification of current space missions.
In the field of aerospace, navigation sensors are divided into two categories: one is the rendezvous and docking optical imaging sensor (CRDS) for on-orbit mission spacecraft such as Shenzhou spacecraft and Tiangong-1 target aircraft. Follow-up on-orbit operation is also included. This type of product is needed to provide protection; the other type is an intersection measurement Optical Imaging Sensor (NLS) for failed satellites or space debris.