An improved two-manoeuvre method for orbit rendezvous with constant thrust

Abstract

An improved two-manoeuvre method to the two-point boundary value problem for arbitrary non-coplanar elliptic orbital rendezvous with constant thrust is proposed. The initial required velocity is obtained by solving Lambert's problem. A new method is proposed to determine the optimal thrust direction to nullify the velocity variation. The optimal direction is close to the direction of the velocity-to-be-gained vector. Therefore, the velocity-to-be-gained guidance method is adopted in both the first and the second engine manoeuvres. The total rendezvous process requires a closed-loop feedback control in the first manoeuvre and an open-loop control in the second one. Compared with existing methods based on the linear relative motion equations, this new approach can be used in the cases of far relative ranges and long rendezvous times. Numerical simulations show that the proposed method is feasible.