利用连续推力的人工太阳同步轨道设计方法

针对人工太阳同步轨道的设计方法进行研究，通过施加法向连续推力调整升交点赤经（RAAN）变化率。首次推导了升交点赤经在变方向推力作用下的周期摄动平均值的精确计算公式，解决了已有近似方法对相关轨道参数的取值范围存在限制的问题，并给出了对应的轨道倾角周期摄动平均值计算公式。在分析J2项摄动对升交点赤经影响的基础上，给出了所需的法向连续推力幅值和一个轨道周期内对应的速度增量的计算方法。通过数值仿真，校验了计算公式的正确性，分析了实现人工太阳同步轨道的连续法向推力对轨道倾角的影响，给出了连续推力幅值随轨道参数的变化规律，并且提出了未来工程任务的应用建议。

Design of Artificial Sun Synchronous Orbit Using Continuous Low Thrust

The control technique of the artificial sun-synchronous orbit is analyzed, a continuous cross-track low-thrust which switches sign as a function of the latitude argument is adopted to regulate the rotation of right ascension of ascending node (RAAN). The accurate formulation of the average variation of RAAN over one orbital period caused by the cross-track control is proposed, which does not restrict the eccentricity to be small or brings secular excursion on the RAAN; moreover, the accurate formulation of the average variation of inclination over one orbital period caused by the cross-track control is proposed. The magnitude of the continuous thrust and the corresponding velocity increment are given on the basis of the calculation of the effect of J2 perturbation on RAAN. Simulation illustrates the validity of the formulation presented in this paper, the example involving large eccentricity is considered, and the effect of the cross-track thrust on the inclination is shown. The variation of the continuous thrust magnitude caused by the initial values of the orbit parameters are analyzed, and the advice for future application is proposed.