How was the Shanghai “space postman” refined

The eighth Institute of China Aerospace Science and Technology Group Co., Ltd. has undertaken the research and development of the Long March 5 Booster and chang’e-5 orbiter. Four boosters provide 90% of the thrust of the Long March 5. As an active vehicle, the orbiter will undertake the tasks of Earth Moon transportation, lunar orbit rendezvous and docking, and sample container transfer. It will realize the first unmanned automatic rendezvous and docking and sample transfer in lunar orbit, the first separation of deep space environment in China, and the first moon earth transfer incident. < p > < p > chang’e-5 probe. China Aerospace Science and Technology Group Co., Ltd. plans to assist chang’e-5 lunar exploration: after the launch of the Shanghai brand “Sanduo” orbiter, the chang’e-5 orbiter carries the lander, ascent and reentrant to complete the Earth Moon transfer, midway correction and near moon braking. After entering the orbit around the moon, the orbiter separates from the landing and ascending combination and carries the reentrant to stay in orbit. After that, the orbiter will carry out active rendezvous and docking with the ascender taking off from the lunar surface, completing the first automatic rendezvous and docking mission of human lunar orbit, and transfer the sample container carried by the ascender to the reentrant; after separation from the docking module and the ascent combination, the orbiter will carry the reentrant into the lunar earth transfer orbit, and the orbit will be at a distance from the earth The reentry device was separated at 5000 km and the initial reentry condition was ensured. < / P > < p > first, there are many flight stages. The orbiter is involved in 8 of the 11 flight stages of the probe system, such as launch, Earth Moon transfer, near moon braking, circumlunar operation, lunar descent, lunar work, lunar rise, rendezvous and docking, lunar waiting, lunar earth transfer and reentry recovery. The other is that there are many states between devices. There are six kinds of combined states of orbiter in the flight process, which undertake the key tasks such as separation, rendezvous and docking, sample transfer and so on. There are many kinds of combination flight states, and the interface between them is complex. The mission process of the orbiter has to undergo multiple orbit changes and attitude adjustment. The orbital flight and attitude control are difficult, and the reliability requirements of the aircraft, electrical and thermal interfaces are high. The third is that the separation times are more. The whole process involves five separations, including separation from the rocket, separation from the landing ascent assembly, separation from the support module, separation from the docking module riser assembly, separation from the reentrant. There are many separation times in orbit, the separation environment is complex, and the system design is very difficult. < / P > < p > “in the whole mission process, the orbiter has five separation times and six combination states. It undertakes the key tasks of Earth Moon transportation, separation between vehicles, rendezvous and docking, and sample transfer. It is one of the most complex space vehicles at present.” Zha Xuelei, deputy chief designer of chang’e-5 detector of the eighth Academy of China Aerospace Science and technology group, said. In view of the characteristics of the whole mission, such as multiple flight states, multiple interfaces between vehicles, multiple working modes, difficulty in tackling key technical problems, difficulties in ground verification, and the new “three more, two difficult and one new” characteristics of the launch and launch site, the research team has broken through four key technologies. < / P > < p > the structure of chang’e-5 detector, the bottom is the orbiter. High reliable connection and separation technology: the chang’e-5 probe is composed of four parts. The state of multi device division and cooperation creates the deformation process of continuous separation, combination, re separation and re combination in space, which is unique among Chinese spacecraft. The orbiter has five separation surfaces, which is one of the difficulties in the development of the detector. It is necessary to ensure the stable connection of the orbiter and the separation process. < / P > < p > the traditional method of strap connection between compartments is abandoned, and multi-point high-strength separation nuts are used for connection. Different numbers of separation screws 75 nuts are arranged on each separation surface to meet the requirements of strength and stiffness of connection between compartments. At the same time, the double acting release nut contains two sets of unlocking mechanisms, and any set of action can ensure the reliable separation of each separation point on the separation surface. The key technologies of connection unlocking and separation with stable connection and reliable separation have made chang’e-5 a leisurely flight. < p > < p > chang’e-5 will implement the world’s first lunar orbit autonomous rendezvous and docking and sample transfer at 380000 km away. The accuracy and alignment of the moving position in the docking mechanism are the key factors affecting the transfer of the sample container, and the docking accuracy is required to reach millimeter level. < / P > < p > in order to solve this problem, the eighth Institute of Aerospace Science and Technology Group creatively developed a claw type docking mechanism, which can realize the automatic transfer of sample containers while automatic unmanned rendezvous and docking can be realized with the help of pawl transfer mechanism. This technology is the first in the world, which has achieved a very important link in the sampling and returning of Chang’e flying sky. < / P > < p > on this basis, the R & D team has also built four world-class ground test systems, including complete machine characteristic test bench, performance test bench, comprehensive test bench and thermal vacuum test bench, to fully verify the effectiveness of ground test of docking and sample transfer mechanism. < / P > < p > the schematic diagram of the whole probe propelled by the orbiter to the moon. Overall optimization and structure Lightweight Technology: light as a swallow, high load is affected by the overall weight of the detector, the orbiter has a strong bearing capacity, but also to be as light as a swallow. < / P > < p > in order to achieve the perfect proportion of the body, seven innovative technologies, such as the lightweight structure with large bearing complex configuration, the first innovative use of multiple separation complex configuration, the first use of multi redundant path composite force transfer structure, the first time the use of large bearing composite material integrated molding and variable thickness bearing spherical crown technology, the structure mass ratio reaches 9.6%, which is really achieved The efficiency is the best. Only 46 kg load-bearing spherical crown can carry 3 tons of tank, with the ultimate bearing capacity of 30 tons, truly achieve “hanging the weight on the eggshell”. < / P > < p > through active and innovative design, the orbiter has a strong iron bone inside and a perfect figure on the outside. It can hold up the flying dream and hold each movement stably, thus achieving a reliable flying Chang’e. < / P > < p > the design of the orbiter is divided into different compartments, and each cabin has corresponding requirements for power distribution management, thermal control management and information management. If the electrical design of the whole unit is carried out according to the traditional mode, a large number of cross cabin cables are required for information exchange, which will burden the weight design, separation surface design, cable network design and overall assembly of the orbiter. < p > < p > for this reason, the research team innovatively put forward the design idea of distributed integrated electronic stand-alone with sub regional management. Through regional division and overall layout, the connection between cables passing through cabins and hard wires in cabins can be reduced as much as possible. At the same time, the team also innovatively put forward the regional, standardized and modular design ideas for the electrical management of the whole device. Through the development of a series of standards and specifications, the integrated electronic system can achieve neat standards from the inside to the outside, flexible assembly, easy expansion, stable software, good signal transmission, ignition of initiating devices, and control of the mechanism. At present, the distributed integrated electronic technology has been widely applied in many kinds of aircraft, which has made a new way different from the past. Continue ReadingASMC, a lithography maker, was one of TSMC’s 14 top suppliers last year