Sliding mode controller for re-entry dynamics of spacecraft reusable type Starship

The behavior of a reusable Starship spacecraft during re-entry into Earth's upper atmosphere is governed by aerodynamic principles. This study aims to develop a sliding mode controller by constructing a nonlinear dynamic model with three degrees of freedom, considering external perturbations. The methodology involves applying a sliding mode control law to manage vibrations due to air friction, impact pressure on the spacecraft's front surface, and lateral friction. Simulation results demonstrate that the initial approximation of the spacecraft's reference and control trajectory achieves stable control behavior and safe re-entry. The controller's reliability and the stability of the closed-loop system are significantly enhanced, though transient responses vary due to the nonlinearity of re-entry dynamics.