行星借力地木转移轨道优化与星历模型下中途修正设计

Gravity-assist Earth-to-Jupiter transfer trajectories optimization and midcourse correction design in ephemeris model

木星系探测具有重要的科学意义与战略价值,而地木转移是实现木星系探测的关键基础。基于行星借力飞行技术对地球木星转移轨道进行了优化设计,并在高精度星历模型中针对实际飞行可能存在的轨道误差设计了中途修正策略。基于Tisserand图分析行星借力飞行序列;以进入环木轨道探测器质量最大化为目标,构建考虑行星星历的借力飞行转移轨道优化非线性规划模型;针对实际飞行误差设计多次借力飞行轨道的中途修正策略;以中国木星系探测任务论证为背景,以2034—2036年为发射窗口,在长征5号运载火箭发射能力下,得到了多种借力转移序列的最优与次优转移方案。结果表明:金星-地球-地球借力转移的最优解可以使进入目标环木轨道的探测器质量达到4 340.8 kg,相比霍曼转移提高约1 300 kg,而后在星历模型下用蒙特卡罗仿真验证中途修正策略,结果显示,在各种误差情况下终端B平面脱靶量小于50 km,且修正脉冲消耗较小,证明所设计的行星借力转移轨道和中途修正策略能够在高精度力学环境中实现地木转移任务,可为中国木星系探测任务设计提供参考。

The Jupiter system exploration has important scientific significance and strategic value,and the Earth-to-Jupiter transfer is the key basis for Jupiter system exploration.The optimal design of Earth-to-Jupiter transfer trajectories is carried out using gravity-assist flight technology,and the midcourse correction strategy is designed to reduce orbit errors during actual flight in the high-precision ephemeris model.First,gravity-assist flight sequences were analyzed through the Tisserand graph.Second,in order to maximize the mass of the probe entering the orbit around Jupiter,a nonlinear programming model is established to optimize the planet-assisted transfer trajectories by considering the planetary ephemeris.Then,the midcourse correction strategy is designed to eliminate actual flight errors of the multiple gravity-assist flight trajectories.Finally,with China’s Jupiter system exploration mission as an example,the optimal and suboptimal transfer solutions of various gravity-assist sequences are obtained by considering the capability of the Long March 5 launch vehicle in the launch window between the year 2034 and 2036.The results show that the optimal solution of the Venus-Earth-Earth-assisted transfer can make the mass of the probe entering the target orbit around Jupiter reach 4340.8 kg,which is about 1300 kg higher than that of the Hohmann transfer.Monte-Carlo simulations validate the midcourse correction strategy in the ephemeris model.The results show that under various errors,the final B-plane miss distances are less than 50 km,and the correction pulse consumption is small,which proves that the designed gravity-assist transfer trajectories and midcourse correction strategy can realize the Earth-to-Jupiter transfer mission in the high-precision mechanical environment and can provide a reference for the design of China’s Jupiter system exploration mission.