The concept of frozen orbit has been applied in space missions mainly for orbital tracking and control purposes. This type of orbit is important for orbit design because it is characterized by keeping the argument of perigee and eccentricity constant on average, so that, for a given latitude, the satellite always passes at the same altitude, benefiting the users through this regularity. Here, the system of nonlinear differential equations describing the motion is studied, and the effects of geopotential and atmospheric drag perturbations on frozen orbits are taken into account. Explicit analytical expressions for secular and long period perturbations terms are obtained for the eccentricity and the argument of perigee. the classical equations of Brouwer and Brouwer and Hori theories are used. Nonsingular variables approach is used, which allows obtaining more precise previsions for CBERS (China Brazil Earth Resources Satellite) satellites family and similar satellites (SPOT, Landsat, ERS, and IRS) orbital evolution.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)EEL USP LOB, Engn Sch Lorena, BR-12602810 Lorena, SP, BrazilUniversidade Federal de São Paulo UNIFESP, ICT, BR-12231280 Sao Jose Dos Campos, SP, BrazilNatl Inst Space Res INPE DMC, Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, ICT, BR-12231280 Sao Jose Dos Campos, SP, BrazilFAPESP: 2012/21023-6Web of Scienc
