Conclusion
Space Trajectories. Atmospheric reentry

Atmospheric re-entry is a critical phase of a space mission. This article reviews the equations of motion of the hypersonic glide phase and details the main analytical solutions. These simplified solutions enable rapid analysis in preliminary design or mission scenario preparation.

For some missions, aerodynamic braking is insufficient and must be supplemented by other means. Interplanetary missions can make several passes through the atmosphere (aerobraking) to progressively reduce energy. The suborbital return of a reusable launcher stage requires an aerobic propulsion system or rocket, the consumption of which must be minimized. These missions call for global optimization of the ascent and return phases.