Optimal Supersonic Air-Launching Rocket Design Using Multidisciplinary System Optimization Approach

Abstract

Compared with the conventional ground rocket launching, air-launching has many advantages. However, comprehensive and integrated system design approach is required because the physical geometry of air launch vehicle is quite dependent on the installation limitation of the mother plane. Given mission objective is to launch 7.5kg nano-satellite to the target orbit of 700km x 700km using the mother plane, F-4E Phantom. The launching altitude and velocity are 12km, Mach number 1.5, respectively. As the propulsion system, a hybrid rocket engine is used for the first stage, and the solid rocket motors are used for the second and third stages. The total mass, length and diameter constraints of the rocket are imposed by the mother plane. The system design has been performed using the sequential optimization method. Gradient based SQP(Sequential Quadratic Programming) algorithm is employed. Analysis modules include mission analysis, staging, propulsion analysis, configuration, weight analysis, aerodynamics analysis and trajectory analysis. As a result of system optimization, a supersonic air launching rocket with total mass of 1272.61kg, total length of 6.43m, outer diameter of 0.60 m and the payload mass of 7.5kg has been successfully designed.