An efficient tool for the propagation and control of geosynchronous orbits

The considered study is concerned with the development of an orbit ephemeris propagator that is useful for low inclination, low eccentricity geosynchronous satellite orbits. A semianalytical technique is used in which the perturbations due to earth zonal and tesseral harmonics to 4th order, sun-moon attractions, and solar radiation pressure are averaged over one satellite revolution. The averaged element rates are then numerically integrated with step sizes of one day, allowing for rapid, yet accurate ephemeris prediction over years of mission duration. The propagator contains algorithms for automatically and optimally controlling longitude of ascending node, inclination and argument of perigee. Typical stationkeeping requirements for these three parameters are 2, 50, and 8 m/sec per year, respectively.