A general description of the problems associated with performing a safe descent of a spacecraft to Earth or another planet with an atmosphere is given. The limitations imposed on refueling and thermal modes are discussed, the aerodynamic characteristics of various types of spacecraft are analyzed. Analytical and semi-analytical methods for calculating atmospheric escape trajectories are compared, and the areas of applicability of the obtained approximate solutions are determined. Problems on optimization of entry trajectories are investigated, the main types of disturbances, navigation and control methods are analyzed.