嫦娥五号轨道器分离系统设计与验证

Design and test of a separation system for Chang’e-5 orbiter

嫦娥五号轨道器实现了中国首次月球轨道的多次分离任务.月球探测器重量限制苛刻,月球轨道空间环境复杂,连接分离任务可靠性、安全性要求高,分离系统的设计与验证难度大.本文介绍了轨道器分离系统的功能与组成、各分离面的配置、关键单机方案、分离动力学仿真分析、超高真空分离面防冷焊设计、分离系统地面验证试验.在分离系统方案中,针对重量限制苛刻难题,提出了采用大承载、轻小型的点式连接分离的方案;针对分离可靠性高的难题,发明了一种枢轴式双作动火工连接解锁机构,实现了解锁分离环节的全链路冗余;针对分离安全性高的难题,识别出分离体质心横移、弹簧分离装置输出力的偏差、弹簧分离装置刚度变化、解锁不同步性等影响要素,并采取相应的设计措施;针对大温差、微重力空间环境下分离系统验证难,提出了基于热-结构-流体多场耦合特征的分离仿真分析方法,并提出了气液电联动控制的液压重力平衡方法和大型航天器分区联动温控方法,研制了相应的分离试验系统,进行了地面试验.经飞行试验验证,嫦娥五号轨道器各分离面在轨正常解锁分离,分离姿态平稳,表明轨道器分离系统设计正确,可靠性高,地面仿真和试验验证方法有效,验证充分,满足任务要求.

The Chang’e-5 orbiter achieved China’s first multiple-separation missions in the lunar orbit. Because of the strict weight limit of the lunar probe, the complicated space environment of the lunar orbit, and the high reliability and security requirement of connection separation missions, it is difficult to design and verify the separation system. This paper introduces the function and composition of the separation system of the orbiter, the configuration of each separation interface, the key device scheme, separation dynamics simulation analysis, ultrahigh vacuum-separation interface cold-welding protection design, and the ground verification test of the separation system. For the problem of harsh weight limitation, we proposed a large load-bearing, light, and small point-type connection separation scheme. In response to the problem of high separation reliability, a pivot-type double-acting pyrotechnic connection-unlocking mechanism was invented to achieve full-link redundancy of the unlocking and separation link;to solve the problem of high separation safety, we identified the influencing factors, such as the transverse displacement of the separation body mass, deviation of the spring separation device output force, change in the spring separation device stiffness, and unlocking asynchrony, and we took corresponding design measures. Because of the difficulty in verifying the separation system under a large temperature difference and microgravity space environment, a separation simulation analysis method based on the coupling characteristics of the thermal-structural-fluid multifield, hydraulic gravity balance method of gas-hydraulic-electric linkage control,and large spacecraft zonal linkage temperature control method were proposed;then, the corresponding separation test system was developed and the ground tests were performed. A flight test showed that the separation system of the Chang’e-5 orbiter is correct and meets the mission requirements.