This thesis investigates the application of Encke’s methods to the maneuver of station keeping. In general, a low-earth-orbit (LEO) satellite orbits the earth at the altitude of 300 to 800 km. Even though the air density is quite low at such a height, the influence of air drag to the orbit is still quite huge due to long time accumulation. In order to maintain the height of the satellite, a station-keeping maneuver should be performed if the satellite falls out the acceptable region. At the phase of preliminary orbit design, the numbers and total fuel cost of station keeping should be estimated to approximate the fuel to carry for the whole mission. This thesis approaches the problem with a case study. A virtual satellite mission is investigated in the thesis. However, the methodology is applicable to all space missions in the future. At beginning, the satellite is performed an orbit transfer with Hohmann transfer to simulate a real space mission, where the main fuel is used for the orbit transfer and the remaining fuel is used for station keeping. Then the air density, the drag coefficient, and influence of solar activities are studied. With the knowledge of potential disturbances, the Enche’s method is employed to estimate the decay of the orbit radius. At the end of the thesis, an virtual space mission is presented as an example to demonstrate how Enche’s method can be employed for the maneuvers of station keeping. The results of this thesis are potentially applicable to estimate the fuel to carry in the perspective space missions.