Abstract: Autonomous midcourse correction is a key technique to facilitate autonomy of an interplanetary spacecraft. Using B-plane parameters as target parameters and impulse control method combined with linear guidance, an autonomous orbit correction method used during cruise phase of interplanetary orbit is proposed.First, the navigation system periodically determines positions and velocities of the spacecraft. The state is than mapped forward to the B-plane by integrating the dynamics model precisely. If deviation from the desired encounter condition is large enough and isn’t out of the capability of autonomous midcourse correction system, the velocity increment for correction maneuver is computed by using linear guidance formula combined with Newton iteration method. The sensitivity matrix of target parameters relative to control parameters is numeri-cally computed using finite central difference formula. Monte Carlo Simulation shows that this method is capa-ble of guiding the spacecraft to a successful encounter.

Key words: midcourse correction, B-plane, transfer orbit, deep space exploration