Rapid ascent trajectory optimization for a solid rocket engine vehicle

A rapid ascent trajectory optimization approach is presented for a solid rocket powered vehicle. The combustion time of the solid rocket engine is limited, leading to shortest time climbing trajectory design problem. With a single-chamber dual-thrust motor thrust characteristic introduced, the model of ascent trajectory optimization is established. The trajectory optimization problem is an optimal control problem containing a set of differential equations. First, the gauss pseudospectral method is adopted to parameterize the differential equations, so the optimization is transformed into a nonlinear programming problem. Then, by using the sequential quadratic programming algorithm to solve the nonlinear programming, the optimal trajectory and the optimal control law is obtained. The simulation result proves that the trajectory optimization method is effective, and the solving speed and precision is satisfactory.