H-2 OPTIMAL HALO ORBIT GUIDANCE

An output feedback guidance law for a halo orbit about the translunar equilibrium point in the circular restricted three-body problem is dev eloped. The equations of motion are derived and the location and stabi lity of the translunar equilibrium point discussed. The halo orbit gui dance problem is formulated in the frequency domain from which an outp ut feedback guidance law is developed using H-2 control theory. Simula tion results validate the guidance law and provide data that quantify the effect of control inputs, noise characteristics, and halo orbit ch aracteristics on the steady-state halo orbit stationkeeping costs.