The safety of crews is the primary concern in the manned lunar landing project, particularly during re-entry as the manned spacecraft returns from a direct Lunar-Earth trajectory. This paper analyzed the crew’s chest biomechanical response to assess potential injuries caused by acceleration loads during the re-entry phase. Initially, a sophisticated finite element model of the chest was constructed, whose effectiveness was verified by experiments involving vertebral range of motion, rib lateral rupture, and chest frontal impact. The model was then subjected to the return re-entry loads simulating the Apollo and Chang’e 5 T1 (CE-5T1) test returner to specifically analyze the correlation between the acceleration load and the injury of the crew’s chest tissues and organs. The results indicate that the biomechanical response of crew chest bone tissue under the two return missions is within the threshold value and will not directly cause damage. Compared to the Apollo mission, the CE-5T1 mission’s load poses a higher risk to internal organs. These findings can enhance the crew’s safety and provide reliable assurance for future space exploration.

中文翻译：

---

月球-地球再入返回过程中乘员胸部载荷的模拟与分析

宇航员的安全是载人登月项目的首要关注点，特别是在载人航天器从直接月球-地球轨道返回时的重返过程中。本文分析了机组人员胸部生物力学反应，以评估重返阶段加速载荷造成的潜在伤害。最初，构建了复杂的胸部有限元模型，并通过涉及椎体运动范围、肋骨横向断裂和胸部正面撞击的实验验证了其有效性。然后对该模型进行模拟阿波罗和嫦娥五号T1（CE-5T1）测试返回器的返回再入载荷，具体分析加速载荷与乘员胸部组织器官损伤的相关性。结果表明，两次返回任务下乘员胸部骨组织的生物力学响应均在阈值以内，不会直接造成损伤。与阿波罗任务相比，CE-5T1任务的负载对内脏器官造成的风险更高。这些发现可以增强宇航员的安全，为未来的太空探索提供可靠的保证。