Control acceleration magnitudes for the laser-interferometric gravitational-wave observatory. The left panel shows the contour map of the control acceleration magnitudes (u_d = ||u_d||) with respect to the separation (defined as r_r) and altitude. The gray lines show the borderlines that indicate when to change the mitigation methods for the secular and long-period drifts of the eccentricity vector. For the secular and long-period eccentricity drift owing to lunar gravity, the more propellant-saving approach appeared above the lines (specified by e^(s)(Moon) and e^(lp)(Moon)) when applying method (c) for the secular one and (b) for the long-period one in Fig. 1, while it appeared below the lines when applying method (a) in Fig. 1. For the long-period eccentricity drift owing to Earth’s J₃ gravity, the more propellant-saving approach appeared above the line (specified by e^(lp)(J₃)) when applying method (a) in Fig. 1, while it appeared below the line when applying method (b) in Fig. 1. The borderlines for the secular and long-period drifts of the eccentricity vector owing to solar gravity were abbreviated because their magnitudes were sufficiently smaller than 10⁻⁹ m s⁻² in the plotted region. The right panel shows the control acceleration magnitudes at the desired separation with respect to the semimajor axis. The atmospheric drag and secular and long-period drift of the eccentricity vector owing to solar gravity were removed from the figure because their magnitudes were sufficiently smaller than 10⁻⁹ m s⁻².