The paper proposes a numerical approach to the problem of optimal control of low-thrust spacecraft in a strong central gravity field. The approach employs the solution of the averaged equations of optimal motion. For an optimal variable-thrust maneuver, it is shown that quasioptimal trajectories are close to the averaged ones. It is established that in the case of constant thrust, the averaged solutions can be used as a satisfactory first approximation for finding a quasioptimal solution by minimizing the discrepancy at the right end of the trajectory Keywords: low-thrust orbit transfer, optimal control, averaging method Introduction. The use of electric main engines for maneuvering in the near-earth space makes the problems of optimal control and optimal transfer trajectories a top priority [1, 11, 13-15, 20-26, 35]. The main difficulty in solving these problems is that the jet acceleration developed by such engines is three to four orders of magnitude less than the gravitational acceleration in low Earth orbits. Therefore, orbit transfers of practical interest may include hundreds and thousands of revolutions around an attracting center. The two-point boundary-value problems to which the above problems are reduced upon the use of Pontryagin's maximum principle have to be solved numerically, even if the central gravity field is Newtonian. In this case, finding the missing initial conditions for the conjugate system by using derivatives of the terminal functional and/or the discrepancy of the final conditions (at the right end of the trajectory) with respect to the control at the beginning of motion involves severe difficulties [10,27], which results in slow convergence of the traditional optimization methods and, most often, makes them impossible to use. As always, whether the problem is solved successfully depends on the initial approximation [12].One of the ways to find the initial approximation is to use the averaging method [2]. Average solutions of the first order were first efficiently constructed for unlimited-thrust engines [16,17,33]. Later, ways were found to average the equations of optimal constant-thrust motion, which is of more practical interest [18,19,29]. Note that the approach proposed in [19] does not allow a qualitative analysis of the averaged equations of optimal motion because their right-hand side contains quadratures that cannot be expressed in terms of elementary functions.Whether a boundary-value problem is solved successfully is still determined by the quality of the initial approximation [5] or by the method used such as the parameter continuation method [11,12]. The approach proposed in [27] and detailed in [5] made it possible not only to evaluate the quadratures, but also to obtain analytic solutions to the averaged equations for maneuvers of practical interest.Computing average orbit transfers in a strong central gravity field would provide a basis for embarking on seeking for methods for the numerical integration of the nonaveraged equations of motion. One method is proposed her...