Orbital evolution of geosynchronous objects with high area-to-mass ratios

The dynamical evolution of objects released in geostationary orbit with area-to-mass ratios (A/M) between 1 and 50 m2/kg was analyzed, both short (a few months) and long-term (54 years), taking into account geopotential harmonics (8 × 8), luni-solar perturbations, direct solar radiation pressure with eclipses and, when applicable, air drag. The results obtained confirm that such objects may be good candidates to explain the recently discovered debris population with mean motions of about one revolution per day and orbital eccentricities as high as 0.55. More specifically, for A/M > 40 m2/kg, orbital decay is attained in less than 40 months due to the eccentricity rise, while, for lower values of the area-to-mass ratio, a lifetime of at least two decades was found. Increasing A/M from 1 to 15 m2/kg, the amplitude of the short-term eccentricity oscillation grows from about 0.03 to 0.3, while the long-term variation increases from approximately 0.02 to 0.5. Above 15 m2/kg, the pattern of eccentricity evolution becomes more complicated, with typically larger excursions. Concerning the inclination evolution, objects with A/M = 1 m2/kg exhibit the classical behavior of a typical abandoned geostationary spacecraft. However, a further increase of the area-to-mass ratio has as consequence a faster orbit pole precession and wider amplitude of the plane motion.