In this study, we consider a generic chaser spacecraft capable of reaching any target belonging to a given set of objects located in different sun-synchronous low Earth orbits (LEO). The entire mission must be completed within a given time period. Once launched from Earth, the chaser reaches a set of targets where it provides the required services and finally returns to Earth (or performs a destructive re-entry). Since different sequences and target selections are generally possible, some optimization criteria (such as total economic value) can be considered. The orbit transfer strategy adopted here aims to exploit Earth J2 perturbations in order to achieve considerable propellant savings which can maximize the feasible number of services, enabling the in-orbit servicing LEO market. A number of specific operational conditions are considered. Since the problem is combinatorial in nature, it is approached allying mixed integer linear programming.