Hybrid combustion technology has recently been employed in the sounding rocket developments to support the science experiments of academic applications and the establishment of a viable flight test platform for space components development. In this paper, hybrid combustion sounding rocket development approach and strategy are described. The present hybrid sounding rocket development program involve multi-disciplinary design practice that covers the areas of propulsion, aerodynamics, thermal protection materials, structure, trajectory/attitude, flight computer avionics, telemetry, ground support and payload processing. Among these disciplines, advancement in hybrid propulsion technology presents the major contribution to the hybrid rocket designs in this research. Computational fluid dynamics (CFD) methodology is employed as an efficient and effective tool in the design and analysis of hybrid rocket engine concepts. The main objective is to improve the overall combustion efficiency of hybrid combustion, which features in slow mixing characteristics of typical diffusion flames. Innovative design concepts are analyzed and improved with advanced multi-physics CFD models using parallel computing to improve the combustion efficiency of the design. The numerically designed hybrid rocket engines are validated with hot-fire experiments. Two mixing enhancing designs are obtained as a result of this investigation.