ORBITEC proposes to develop a unique Advanced Vortex Hybrid Rocket Engine (AVHRE) to achieve a safe, highly-reliable, low-cost and uniquely versatile propulsion system. The benefits of AVHRE result from the combination of four innovations: (1) the patented vortex injection technique which generates a coaxial vortex pair, driving high solid-fuel regression rates and improved combustion efficiency; (2) high-regression rate paraffin solid fuels; (3) patented regression sensor technology, and (4) a new fuel formulation innovation to control the solid fuel regression characteristics and provide improved structural integrity of the grain. These innovations simplify hybrid rocket design, development, and manufacture both inherently and by providing many practical design degrees of freedom that can be harnessed for a given application. Specific benefits of the AVHRE technology include: (1) increased propellant mass fractions; (2) the ability to tailor and optimize a hybrid propulsion system for a given application; (3) increased ISP efficiency; (4) a reduction or elimination of residual fuel; (5) improved grain structural integrity and increased thermal properties; and (6) reduced need for thermal insulation. The Phase II effort will design, develop, and test a 10,000 lbf AVHRE-I chamber and a suite of practical AVHRE engineering design tools that will be delivered to NASA upon completion of the project.