飞向Halo轨道的太阳帆航天器轨迹优化设计

研究太阳帆航天器从地球同步轨道飞向日-地第2Lagrange(L2)点Halo轨道时其转移并入轨的轨迹优化设计问题。提出了分3阶段优化设计的方法:首先调整航天器逃离地球的飞行轨迹,使其比较接近目标Halo轨道的不变流形;再借助不变流形,用遗传算法求解相应的最优控制,使其转移到目标Halo轨道的不变流形上;最后航天器将沿流形飞行完成入轨。数值仿真结果表明,提出的方法可以得到相当好的转移轨道。由此显示,将转移轨道分为若干阶段,借助不变流形,用遗传算法求解最优控制问题的轨道优化设计方法对于此类小推力变轨问题是切实可行的。

Optimal trajectory design of solar sail transfer to halo orbits

Solar sail transfer from earth-synchronous orbits to Sun-Earth L2 halo orbits was explored.A three-stage optimization method first adjusts the earthescape trajectory to get the sail close to the invariant manifold of the desired orbit.Then,the orbit is selected so as to transfer to the manifold by solving an optimal control problem for the invariant manifold using a genetic algorithm.Finally,the sail flies to the desired halo orbit along its invariant manifold.Numerical simulations show that this method produces good results.Division of the transfer orbit into several stages with the optimal control problem for the invariant manifold solved using a genetic algorithm gives an efficient method for this kind of low-thrust orbit-transfer problems.