平面引力辅助中施加脉冲的最优位置

在引力辅助过程中施加脉冲可以改善变轨效果。虽然轨道设计中一般将施加脉冲的位置设置在轨道的近拱点,但是并没有研究表明近拱点是施加脉冲的最优位置。为了研究平面引力辅助中施加单次共面脉冲的最优位置,首先采用6个参数对变轨过程进行描述,其中3个参数表征平面引力辅助、2个参数表征脉冲的大小与方向、1个参数表征施加脉冲的位置。然后将航天器的状态向量表示成参数的函数,进而求出变轨之后航天器的能量变化。研究施加脉冲的位置对航天器能量的影响,结果表明最优位置一般并不是近拱点,在最优位置施加脉冲比在近拱点有时可高效20%以上。

Best position to apply an impulse in a planar swing-by

Applying an impulsive thrust during a close encounter with a celestial body can significantly improve the efficiency of the swing-by maneuver. The impulse is usually applied at the periapsis in much literature, but there is no proof that periapsis is the optimal position. In order to study the best position to apply an impulse in a planar swing-by, the powered swing-by is described by the three usual parameters of the standard swing-by maneuver plus the three parameters which specify the magnitude, the direction and the position of the impulse. A set of new analytical equations are derived, including the variation in velocity, energy and angular momentum due to the maneuver as a function of the six parameters. Using these equations, it is possible to find the best position to apply the impulse to maximize the energy change. The results show that periapsis is not the best position, as the application of impulse in the best position is 20% more efficient than the application of impulse at the periapsis in some cases.