月球返回舱跳跃式再入弹道设计方法研究

Skip entry trajectory design for lunar return module

不同于近地航天器返回地球,月球返回舱存在再入速度更高、大气和气动参数误差影响更大以及再入动力学耦合更强烈的特点。为缓解这些突出问题,降低月球返回舱所受到的冲击,对跳跃式再入弹道进行了研究,给出了跳跃式返回弹道的设计流程和算法,分析了不同再入角和航程约束下的弹道形态,并针对7 500 km航程可能出现的横向超调现象提出了3种解决方案。其中控制出口射面法引入了"预测-校正"思想,从根本上解决了自由飞行段可能出现的问题。数值仿真结果验证了弹道设计流程和算法的有效性。

The lunar return module has its own characteristics, including higher entry velocity, more un- certainty of atmospheric density and aerodynamic parameters, stronger coupled dynamics, which is different from the near earth spacecraft. To ease these difficulties and reduce the impact on the lunar returns module, a research on skip entry trajectory was designed. The generalized design process and algorithm for skip entry trajectory were presented, and the trajectory parameter profiles of different entry flight-path angle and range were analyzed. Three solutions for the possible uncontrollable condition of crossrange for range 7500 km were developed. The approach of ＂shooting plane determination＂ solved the problem thor- oughly, which introduced the strategy of ＂predictor-corrector＂. The numerical simulation verifies the a- vailability of the trajectory design process and algorithm.